can I get a second set of eyes on this. I'm trying to write a Signup activity and it keeps crashing on me. I've been struggling since last night. Can anyone point out what I'm doing wrong?
Here is the activity code
package mw.technology.app.ribbit;
import android.app.Activity;
import android.app.AlertDialog;
import android.app.Fragment;
import android.os.Bundle;
import android.view.LayoutInflater;
import android.view.Menu;
import android.view.MenuItem;
import android.view.View;
import android.view.ViewGroup;
import android.widget.Button;
import android.widget.EditText;
public class SignUpActivity extends Activity {
protected EditText mUsername;
protected EditText mPassword;
protected EditText mEmail;
protected Button mSignUpButton;
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_sign_up);
mUsername = (EditText)findViewById(R.id.usernameField);
mPassword = (EditText)findViewById(R.id.passwordField);
mEmail = (EditText)findViewById(R.id.emailField);
mSignUpButton = (Button)findViewById(R.id.signupButton);
mSignUpButton.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View arg0) {
// TODO Auto-generated method stub
String username = mUsername.getText().toString();
String password = mPassword.getText().toString();
String email = mEmail.getText().toString();
username = username.trim();
password = password.trim();
email = email.trim();
if (username.isEmpty() || password.isEmpty() || email.isEmpty()) {
AlertDialog.Builder builder = new AlertDialog.Builder(SignUpActivity.this);
builder.setMessage(R.string.signup_error_message)
.setTitle(R.string.signup_error_tittle)
.setPositiveButton(android.R.string.ok, null);
AlertDialog dialog = builder.create();
dialog.show();
}
else {
// create the new user!
}
}
});
}
#Override
public boolean onCreateOptionsMenu(Menu menu) {
// Inflate the menu; this adds items to the action bar if it is present.
getMenuInflater().inflate(R.menu.sign_up, menu);
return true;
}
#Override
public boolean onOptionsItemSelected(MenuItem item) {
// Handle action bar item clicks here. The action bar will
// automatically handle clicks on the Home/Up button, so long
// as you specify a parent activity in AndroidManifest.xml.
int id = item.getItemId();
if (id == R.id.action_settings) {
return true;
}
return super.onOptionsItemSelected(item);
}
/**
* A placeholder fragment containing a simple view.
*/
public static class PlaceholderFragment extends Fragment {
public PlaceholderFragment() {
}
#Override
public View onCreateView(LayoutInflater inflater, ViewGroup container,
Bundle savedInstanceState) {
View rootView = inflater.inflate(R.layout.fragment_sign_up,
container, false);
return rootView;
}
}
}
And here is the layout code
<FrameLayout xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:tools="http://schemas.android.com/tools"
android:id="#+id/container"
android:layout_width="match_parent"
android:layout_height="match_parent"
tools:context="mw.technology.app.ribbit.SignUpActivity"
tools:ignore="MergeRootFrame" >
<RelativeLayout
android:layout_width="match_parent"
android:layout_height="match_parent"
android:paddingBottom="#dimen/activity_vertical_margin"
android:paddingLeft="#dimen/activity_horizontal_margin"
android:paddingRight="#dimen/activity_horizontal_margin"
android:paddingTop="#dimen/activity_vertical_margin" >
<EditText
android:id="#+id/userName"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:layout_alignParentLeft="true"
android:layout_alignParentTop="true"
android:ems="10"
android:hint="#string/username_hint" >
<requestFocus />
</EditText>
<EditText
android:id="#+id/password"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:layout_alignParentLeft="true"
android:layout_below="#+id/userName"
android:ems="10"
android:hint="#string/password_hint"
android:inputType="textPassword" />
<EditText
android:id="#+id/emailField"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:layout_alignParentLeft="true"
android:layout_below="#+id/password"
android:ems="10"
android:hint="#string/email_hint"
android:inputType="textEmailAddress" />
<Button
android:id="#+id/signupButton"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:layout_alignParentLeft="true"
android:layout_below="#+id/emailField"
android:text="#string/sign_up_button_label" />
</RelativeLayout>
</FrameLayout>
Thanks in advance and I apoligize for my current ineptitude.
Any thoughts?
Related
I have tried searching for answers but i haven't found the fix for my problem yet. I have 2 activities -apple and Bacon. I am trying to learn intents and data passing between activities. The apple activity is supposed to pass the value entered in the EditText field on a button click to the bacon activity which just displays the value.
I am getting the following exception on the stack
Caused by: java.lang.NullPointerException: Attempt to invoke
virtual method 'android.text.Editable android.widget.EditText.getText()'
on a null object reference
The code snippets are as follows:-
apples.xml
<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:tools="http://schemas.android.com/tools" android:layout_width="match_parent"
android:layout_height="match_parent" android:paddingLeft="#dimen/activity_horizontal_margin"
android:paddingRight="#dimen/activity_horizontal_margin"
android:paddingTop="#dimen/activity_vertical_margin"
android:paddingBottom="#dimen/activity_vertical_margin" tools:context=".Apple"
android:background="#009900">
<TextView
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:textAppearance="?android:attr/textAppearanceLarge"
android:text="Apples"
android:id="#+id/applesText"
android:layout_alignParentTop="true"
android:layout_centerHorizontal="true" />
<Button
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:text="Go to Bacon"
android:id="#+id/applesButton"
android:layout_below="#+id/applesText"
android:layout_centerHorizontal="true"
android:layout_marginTop="104dp"
android:onClick="onClickApples"/>
<EditText
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:inputType="textPersonName"
android:ems="10"
android:id="#+id/personName"
android:layout_below="#+id/applesText"
android:layout_centerHorizontal="true" />
Apples.java
package com.example.karan.intentexample;
import android.support.v7.app.AppCompatActivity;
import android.os.Bundle;
import android.util.Log;
import android.view.Menu;
import android.view.MenuItem;
import android.view.View;
import android.content.Intent;
import android.widget.EditText;
public class Apple extends AppCompatActivity {
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_apple);
}
#Override
public boolean onCreateOptionsMenu(Menu menu) {
// Inflate the menu; this adds items to the action bar if it is present.
getMenuInflater().inflate(R.menu.menu_apple, menu);
return true;
}
#Override
public boolean onOptionsItemSelected(MenuItem item) {
// Handle action bar item clicks here. The action bar will
// automatically handle clicks on the Home/Up button, so long
// as you specify a parent activity in AndroidManifest.xml.
int id = item.getItemId();
//noinspection SimplifiableIfStatement
if (id == R.id.action_settings) {
return true;
}
return super.onOptionsItemSelected(item);
}
public void onClickApples(View view){
final EditText applesInput = (EditText)view.findViewById(R.id.personName);
String userMessage = applesInput.getText().toString();
Intent i = new Intent(this, Bacon.class);
//putExtra takes data in the form of a key-value pair
i.putExtra("appleMessage", userMessage);
startActivity(i);
}
}
Bacon.xml
<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:tools="http://schemas.android.com/tools" android:layout_width="match_parent"
android:layout_height="match_parent" android:paddingLeft="#dimen/activity_horizontal_margin"
android:paddingRight="#dimen/activity_horizontal_margin"
android:paddingTop="#dimen/activity_vertical_margin"
android:paddingBottom="#dimen/activity_vertical_margin"
tools:context="com.example.karan.intentexample.Bacon"
android:background="#72231F">
<TextView
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:textAppearance="?android:attr/textAppearanceLarge"
android:text="Bacon"
android:id="#+id/baconText"
android:layout_alignParentTop="true"
android:layout_centerHorizontal="true"
android:layout_marginTop="39dp" />
<Button
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:text="New Button"
android:id="#+id/baconButton"
android:layout_below="#+id/baconText"
android:layout_centerHorizontal="true"
android:layout_marginTop="99dp" />
Bacon.java
package com.example.karan.intentexample;
import android.support.v7.app.AppCompatActivity;
import android.os.Bundle;
import android.view.Menu;
import android.view.MenuItem;
import android.widget.TextView;
public class Bacon extends AppCompatActivity {
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_bacon);
Bundle applesData;
applesData = getIntent().getExtras();
//if there is no data in the intent
if(applesData==null)
return;
//get value by using the key in the getString method
String appleMessage = applesData.getString("appleMessage");
final TextView baconText = (TextView)findViewById(R.id.baconText);
baconText.setText(appleMessage);
}
#Override
public boolean onCreateOptionsMenu(Menu menu) {
// Inflate the menu; this adds items to the action bar if it is present.
getMenuInflater().inflate(R.menu.menu_bacon, menu);
return true;
}
#Override
public boolean onOptionsItemSelected(MenuItem item) {
// Handle action bar item clicks here. The action bar will
// automatically handle clicks on the Home/Up button, so long
// as you specify a parent activity in AndroidManifest.xml.
int id = item.getItemId();
//noinspection SimplifiableIfStatement
if (id == R.id.action_settings) {
return true;
}
return super.onOptionsItemSelected(item);
}
}
Here:
final EditText applesInput = (EditText)view.findViewById(R.id.personName);
view.findViewById causing issue.change it to:
final EditText applesInput = (EditText)Apple.this.findViewById(R.id.personName);
Because EditText with personName id is in Activity layout instead of inside Button layout(view parameter of onClickApples)
public class Apple extends AppCompatActivity {
private EditText applesInput;
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_apple);
applesInput = (EditText)findViewByID(R.id.personName);
}
public void onClickApples(View view){
String userMessage = applesInput.getText().toString();
Intent i = new Intent(this, Bacon.class);
//putExtra takes data in the form of a key-value pair
i.putExtra("appleMessage", userMessage);
startActivity(i);
}
}
I have a 2 activities with edittexts on them the first activity work fine but the second activity's EditText is focused but I can't edit it nor can I click the button on it.
Also everything works in the emulator but not when I install it on the device. (The keyboard popup also does not come up in the second activity where as it does in the first activity)
Below is the code for the1st and second activity
First Activity Class
package com.rohan.rohan_pc.sportappnew;
import android.content.Intent;
import android.os.AsyncTask;
import android.support.v7.app.ActionBarActivity;
import android.os.Bundle;
import android.view.Menu;
import android.view.MenuItem;
import android.view.View;
import android.widget.Button;
import android.widget.EditText;
import android.widget.Toast;
import org.json.JSONArray;
import org.json.JSONException;
import org.json.JSONObject;
public class LoginActivity extends ActionBarActivity {
EditText edtEmail, edtPassword;
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_login);
//Initialize components
edtEmail = (EditText) findViewById(R.id.edtEmail);
edtPassword = (EditText) findViewById(R.id.edtPassword);
Button btnLogin = (Button) findViewById(R.id.btnLogin);
btnLogin.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View view) {
if (edtEmail.getText().toString().length() > 0 && edtPassword.getText().toString().length() > 0) {
new GetAllCustomerTask().execute(new ConnecterClass());
}
}
});
}
#Override
public boolean onCreateOptionsMenu(Menu menu) {
// Inflate the menu; this adds items to the action bar if it is present.
getMenuInflater().inflate(R.menu.login, menu);
return true;
}
#Override
public boolean onOptionsItemSelected(MenuItem item) {
// Handle action bar item clicks here. The action bar will
// automatically handle clicks on the Home/Up button, so long
// as you specify a parent activity in AndroidManifest.xml.
int id = item.getItemId();
if (id == R.id.action_settings) {
return true;
}
return super.onOptionsItemSelected(item);
}
// Connect to the DB
private class GetAllCustomerTask extends AsyncTask<ConnecterClass, Long, JSONArray>
{
#Override
protected JSONArray doInBackground(ConnecterClass... params) {
// Execute in background
return params[0].usrLogin(edtEmail.getText().toString(), edtPassword.getText().toString());
}
#Override
protected void onPostExecute(JSONArray jsonArray) {
if (jsonArray != null) {
JSONObject json = null;
try {
json = jsonArray.getJSONObject(0);
if (edtEmail.getText().toString().equals(json.getString("email"))) {
if (edtPassword.getText().toString().equals(json.getString("pass"))) {
Toast toast = Toast.makeText(getApplicationContext(), "login successful", Toast.LENGTH_SHORT);
toast.show();
Intent intent = new Intent(LoginActivity.this, SearchActivity.class);
//Pass the school_id
intent.putExtra("SCHOOL_ID", json.getInt("school_id"));
startActivity(intent);
} else {
Toast toast = Toast.makeText(getApplicationContext(), "password incorrect", Toast.LENGTH_SHORT);
toast.show();
}
} else {
Toast toast = Toast.makeText(getApplicationContext(), "failed to login ...", Toast.LENGTH_SHORT);
toast.show();
}
} catch (JSONException e) {
e.printStackTrace();
}
//login(edtEmail.getText().toString(),""
/*
//Got to second screen if login is successful
Intent intent = new Intent(LoginActivity.this, AfterLogin.class);
//Pass the table name through
intent.putExtra("CLIENT_DB", clientDB);
startActivity(intent);
*/
}
}
}
}
Second Activity Class
> package com.rohan.rohan_pc.sportappnew;
import android.content.Intent;
import android.os.AsyncTask;
import android.support.v7.app.ActionBarActivity;
import android.os.Bundle;
import android.view.Menu;
import android.view.MenuItem;
import android.view.View;
import android.view.WindowManager;
import android.widget.AdapterView;
import android.widget.Button;
import android.widget.EditText;
import android.widget.ListView;
import android.widget.Toast;
import org.json.JSONArray;
import org.json.JSONException;
import org.json.JSONObject;
public class SearchActivity extends ActionBarActivity {
EditText edtFName, edtLName, edtIDNum;
ListView listViewSearch;
String sFName, sLName, sIDNum;
int school_id;
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_search);
edtFName = (EditText) findViewById(R.id.edtFirstName);
edtLName = (EditText) findViewById(R.id.edtLastName);
edtIDNum = (EditText) findViewById(R.id.edtIDNum);
Button btnSearch = (Button) findViewById(R.id.btnSearch);
listViewSearch = (ListView) this.findViewById(R.id.listViewSearch);
//Initialize the default values for the search criteria variables
sFName = "";
sLName = "";
sIDNum = "";
//Load school_id
school_id = getIntent().getExtras().getInt("SCHOOL_ID");
if(edtFName.requestFocus()) { getWindow().setSoftInputMode(WindowManager.LayoutParams.SOFT_INPUT_STATE_ALWAYS_VISIBLE); }
btnSearch.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View view) {
if(edtFName.getText().toString().length() > 0)
{
sFName = edtFName.getText().toString().trim();
}
if(edtLName.getText().toString().length() > 0)
{
sLName = edtLName.getText().toString().trim();
}
if(edtIDNum.getText().toString().length() > 0)
{
sIDNum = edtIDNum.getText().toString().trim();
}
new SearchAllCustomers().execute(new ConnecterClass());
}
});
}
#Override
public boolean onCreateOptionsMenu(Menu menu) {
// Inflate the menu; this adds items to the action bar if it is present.
getMenuInflater().inflate(R.menu.search, menu);
return true;
}
#Override
public boolean onOptionsItemSelected(MenuItem item) {
// Handle action bar item clicks here. The action bar will
// automatically handle clicks on the Home/Up button, so long
// as you specify a parent activity in AndroidManifest.xml.
int id = item.getItemId();
if (id == R.id.action_settings) {
return true;
}
return super.onOptionsItemSelected(item);
}
//Search in the background
public void setListViewArray(final JSONArray jsonArray)
{
this.listViewSearch.setAdapter(new Search_ListView_Adapter(jsonArray, this));
//Setup what happens when a user clicks on a searched item
this.listViewSearch.setOnItemClickListener(new AdapterView.OnItemClickListener() {
#Override
public void onItemClick(AdapterView<?> parent, View view, int position, long id) {
try{
JSONObject clickedItem = jsonArray.getJSONObject(position);
Intent askActivity = new Intent(getApplicationContext(), AskActivity.class);
askActivity.putExtra("IDNUM", clickedItem.getString("idnum"));
askActivity.putExtra("SCHOOL_ID", clickedItem.getInt("school_id"));
startActivity(askActivity);
} catch (JSONException e) {
e.printStackTrace();
}
}
});
}
// Connect to the DB
private class SearchAllCustomers extends AsyncTask<ConnecterClass, Long, JSONArray>
{
#Override
protected JSONArray doInBackground(ConnecterClass... params) {
// Execute in background
return params[0].searchPlayers(school_id, sFName, sLName, sIDNum);
}
#Override
protected void onPostExecute(JSONArray jsonArray) {
if (jsonArray != null) {
setListViewArray(jsonArray);
//login(edtEmail.getText().toString(),""
/*
//Got to second screen if login is successful
Intent intent = new Intent(LoginActivity.this, AfterLogin.class);
//Pass the table name through
intent.putExtra("CLIENT_DB", clientDB);
startActivity(intent);
*/
}
}
}
}
The XML - First Activity
<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:tools="http://schemas.android.com/tools"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:paddingLeft="#dimen/activity_horizontal_margin"
android:paddingRight="#dimen/activity_horizontal_margin"
android:paddingTop="#dimen/activity_vertical_margin"
android:paddingBottom="#dimen/activity_vertical_margin"
tools:context=".LoginAcivity">
<EditText
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:inputType="textEmailAddress"
android:ems="10"
android:id="#+id/edtEmail"
android:layout_alignParentTop="true"
android:layout_centerHorizontal="true"
android:layout_marginTop="52dp"
android:hint="email ..."
/>
<EditText
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:inputType="textPassword"
android:ems="10"
android:id="#+id/edtPassword"
android:layout_below="#+id/edtEmail"
android:layout_centerHorizontal="true"
android:layout_marginTop="44dp"
android:hint="password ..."
/>
<Button
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:text="New Button"
android:id="#+id/btnLogin"
android:layout_below="#+id/edtPassword"
android:layout_centerHorizontal="true"
android:layout_marginTop="49dp" />
</RelativeLayout>
The XML - Second Activity
<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:tools="http://schemas.android.com/tools"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:paddingLeft="#dimen/activity_horizontal_margin"
android:paddingRight="#dimen/activity_horizontal_margin"
android:paddingTop="#dimen/activity_vertical_margin"
android:paddingBottom="#dimen/activity_vertical_margin"
tools:context="com.rohan.rohan_pc.sportsappv001.SearchActivity">
<TextView
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:textAppearance="?android:attr/textAppearanceLarge"
android:text="Search"
android:id="#+id/textView"
android:layout_alignParentTop="true"
android:layout_alignParentLeft="true"
android:layout_alignParentStart="true" />
<EditText
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:inputType="textPersonName"
android:hint="Name"
android:ems="10"
android:id="#+id/edtFirstName"
android:layout_below="#+id/textView"
android:layout_alignParentLeft="true"
android:layout_alignParentStart="true" />
<EditText
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:inputType="textPersonName"
android:hint="Surname"
android:ems="10"
android:id="#+id/edtLastName"
android:layout_below="#+id/edtFirstName"
android:layout_alignParentLeft="true"
android:layout_alignParentStart="true" />
<EditText
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:id="#+id/edtIDNum"
android:hint="ID Number"
android:layout_below="#+id/edtLastName"
android:layout_alignParentLeft="true"
android:layout_alignParentStart="true"
android:layout_alignRight="#+id/edtLastName"
android:layout_alignEnd="#+id/edtLastName" />
<Button
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:text="Search"
android:id="#+id/btnSearch"
android:layout_below="#+id/edtIDNum"
android:layout_alignParentLeft="true"
android:layout_alignParentStart="true"
android:layout_marginLeft="64dp"
android:layout_marginTop="42dp" />
<ListView
android:layout_width="wrap_content"
android:layout_height="200dp"
android:id="#+id/listViewSearch"
android:layout_alignParentBottom="true"
android:layout_toEndOf="#+id/edtIDNum"
android:layout_alignTop="#+id/edtFirstName"
android:clickable="true"
/>
I just figured to re-create the app. I dont think it is a wise decision to copy the raw files to another directory and use that.
Something very weird is happening in my program. I try to use the button with the first program below (using an emulator) and the program did not even open. So I changed to the second version, using the android:OnClick, and it did not work either (the program opened, but in the click it crashed). Then I tried the third program, using android:onCLick and the instanciation of the EditText in the treatment function, and the program worked.
Can someone explain to me why the first two programs did not worked?
Edit: I noticed now that LogCat is pointing to the following error: error opening trace file: No such file oor directory (2), what is that? Can it have any relation to this error?
And if I comment the definition of the onClickListener to b1 the program do not crash anymore.
First code:
package app.projetnf33;
import android.app.Activity;
import android.app.Fragment;
import android.os.Bundle;
import android.view.LayoutInflater;
import android.view.Menu;
import android.view.MenuItem;
import android.view.View;
import android.view.View.OnClickListener;
import android.view.ViewGroup;
import android.widget.Button;
import android.widget.EditText;
import android.widget.Spinner;
public class MainActivity extends Activity implements OnClickListener{
String[] names;
EditText status;
EditText par1;
EditText par2;
EditText par3;
Button b1;
Button b2;
Button b3;
Button b4;
Spinner spin;
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
status = (EditText) findViewById(R.id.text);
b1 = (Button) findViewById(R.id.b1);
b1.setOnClickListener(new OnClickListener(){
#Override
public void onClick(View v) {
status.setText("Connect");
}
});
if (savedInstanceState == null) {
getFragmentManager().beginTransaction()
.add(R.id.container, new PlaceholderFragment()).commit();
}
}
#Override
public boolean onCreateOptionsMenu(Menu menu) {
// Inflate the menu; this adds items to the action bar if it is present.
getMenuInflater().inflate(R.menu.main, menu);
return true;
}
#Override
public boolean onOptionsItemSelected(MenuItem item) {
// Handle action bar item clicks here. The action bar will
// automatically handle clicks on the Home/Up button, so long
// as you specify a parent activity in AndroidManifest.xml.
int id = item.getItemId();
if (id == R.id.action_settings) {
return true;
}
return super.onOptionsItemSelected(item);
}
/**
* A placeholder fragment containing a simple view.
*/
public static class PlaceholderFragment extends Fragment {
public PlaceholderFragment() {
}
#Override
public View onCreateView(LayoutInflater inflater, ViewGroup container,
Bundle savedInstanceState) {
View rootView = inflater.inflate(R.layout.fragment_main, container,
false);
return rootView;
}
}
#Override
public void onClick(View v) {
// TODO Auto-generated method stub
}
}
Second code
package app.projetnf33;
import android.app.Activity;
import android.app.Fragment;
import android.os.Bundle;
import android.view.LayoutInflater;
import android.view.Menu;
import android.view.MenuItem;
import android.view.View;
import android.view.View.OnClickListener;
import android.view.ViewGroup;
import android.widget.Button;
import android.widget.EditText;
import android.widget.Spinner;
public class MainActivity extends Activity implements OnClickListener{
String[] names;
EditText status;
EditText par1;
EditText par2;
EditText par3;
Button b1;
Button b2;
Button b3;
Button b4;
Spinner spin;
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
status = (EditText) findViewById(R.id.text);
if (savedInstanceState == null) {
getFragmentManager().beginTransaction()
.add(R.id.container, new PlaceholderFragment()).commit();
}
}
public void treatment_connect(View v){
status.setText("Connect");
}
public void treatment_persons(View v){
status.setText("Persons");
}
public void treatment_lecture(View v){
status.setText("Lecture");
}
public void treatment_execute(View v){
status.setText("Execute");
}
#Override
public boolean onCreateOptionsMenu(Menu menu) {
// Inflate the menu; this adds items to the action bar if it is present.
getMenuInflater().inflate(R.menu.main, menu);
return true;
}
#Override
public boolean onOptionsItemSelected(MenuItem item) {
// Handle action bar item clicks here. The action bar will
// automatically handle clicks on the Home/Up button, so long
// as you specify a parent activity in AndroidManifest.xml.
int id = item.getItemId();
if (id == R.id.action_settings) {
return true;
}
return super.onOptionsItemSelected(item);
}
/**
* A placeholder fragment containing a simple view.
*/
public static class PlaceholderFragment extends Fragment {
public PlaceholderFragment() {
}
#Override
public View onCreateView(LayoutInflater inflater, ViewGroup container,
Bundle savedInstanceState) {
View rootView = inflater.inflate(R.layout.fragment_main, container,
false);
return rootView;
}
}
#Override
public void onClick(View v) {
// TODO Auto-generated method stub
}
}
Third code (which worked):
package app.projetnf33;
import android.app.Activity;
import android.app.Fragment;
import android.os.Bundle;
import android.view.LayoutInflater;
import android.view.Menu;
import android.view.MenuItem;
import android.view.View;
import android.view.View.OnClickListener;
import android.view.ViewGroup;
import android.widget.Button;
import android.widget.EditText;
import android.widget.Spinner;
public class MainActivity extends Activity implements OnClickListener{
String[] names;
EditText status;
EditText par1;
EditText par2;
EditText par3;
Button b1;
Button b2;
Button b3;
Button b4;
Spinner spin;
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
if (savedInstanceState == null) {
getFragmentManager().beginTransaction()
.add(R.id.container, new PlaceholderFragment()).commit();
}
}
public void treatment_connect(View v){
status = (EditText) findViewById(R.id.text);
status.setText("Connect");
}
public void treatment_persons(View v){
status.setText("Persons");
}
public void treatment_lecture(View v){
status.setText("Lecture");
}
public void treatment_execute(View v){
status.setText("Execute");
}
#Override
public boolean onCreateOptionsMenu(Menu menu) {
// Inflate the menu; this adds items to the action bar if it is present.
getMenuInflater().inflate(R.menu.main, menu);
return true;
}
#Override
public boolean onOptionsItemSelected(MenuItem item) {
// Handle action bar item clicks here. The action bar will
// automatically handle clicks on the Home/Up button, so long
// as you specify a parent activity in AndroidManifest.xml.
int id = item.getItemId();
if (id == R.id.action_settings) {
return true;
}
return super.onOptionsItemSelected(item);
}
/**
* A placeholder fragment containing a simple view.
*/
public static class PlaceholderFragment extends Fragment {
public PlaceholderFragment() {
}
#Override
public View onCreateView(LayoutInflater inflater, ViewGroup container,
Bundle savedInstanceState) {
View rootView = inflater.inflate(R.layout.fragment_main, container,
false);
return rootView;
}
}
#Override
public void onClick(View v) {
// TODO Auto-generated method stub
}
}
Fragment_layout:
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:orientation="vertical" >
<LinearLayout
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:orientation="horizontal" >
<TextView
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:text="#string/tex_status" />
<EditText
android:id="#+id/text"
android:inputType="text"
android:layout_width="match_parent"
android:layout_height="wrap_content" />
</LinearLayout>
<Spinner
android:id="#+id/spinner"
android:layout_width="wrap_content"
android:layout_height="wrap_content" />
<LinearLayout
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:orientation="horizontal" >
<TextView
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:text="#string/par1" />
<EditText
android:id="#+id/par1"
android:inputType="text"
android:layout_width="match_parent"
android:layout_height="wrap_content" />
</LinearLayout>
<LinearLayout
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:orientation="horizontal" >
<TextView
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:text="#string/par2" />
<EditText
android:id="#+id/par2"
android:inputType="text"
android:layout_width="match_parent"
android:layout_height="wrap_content" />
</LinearLayout>
<LinearLayout
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:orientation="horizontal" >
<TextView
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:text="#string/par3" />
<EditText
android:id="#+id/par3"
android:inputType="text"
android:layout_width="match_parent"
android:layout_height="wrap_content" />
</LinearLayout>
<LinearLayout
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:orientation="vertical">
<LinearLayout
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:orientation="horizontal">
<Button
android:id="#+id/b1"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:drawableLeft="#drawable/ic_action_usb"
android:gravity="center_vertical"
android:text="#string/connect"
android:onClick="treatment_connect" />
<Button
android:id="#+id/b2"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:drawableLeft="#drawable/ic_action_computer"
android:gravity="center_vertical"
android:text="#string/read"
android:onClick="treatment_lecture" />
</LinearLayout>
<LinearLayout
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:orientation="horizontal">
<Button
android:id="#+id/b3"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:drawableLeft="#drawable/ic_action_accept"
android:gravity="center_vertical"
android:text="#string/execution"
android:onClick="treatment_execution" />
<Button
android:id="#+id/b4"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:drawableLeft="#drawable/ic_action_warning"
android:gravity="center_vertical"
android:text="#string/disconnect"
android:onClick="treatment_disconnect" />
</LinearLayout>
</LinearLayout>
In the first and seconds layout you tried to call
status = (EditText) findViewById(R.id.text);
b1 = (Button) findViewById(R.id.b1);
before
getFragmentManager().beginTransaction()
.add(R.id.container, new PlaceholderFragment()).commit();
So you tried to reference a Button and EditText contained in the PlaceholderFragment layout before you created the fragment.
The views are in the fragment layout. It only becomes a part of the activity view hierarchy after the fragment transaction has been run. Your pending fragment transaction is executed in activity super.onStart() which comes only after onCreate(). In essence, you're calling findViewById() too early in the first two versions. The third version works because the findViewById() is in the click handler and gets invoked when the fragment is attached to the activity.
Usually you'd call findViewById() to set up listeners and so on at the earliest possibility in fragment onCreateView(), just after the fragment layout is inflated.
I'm having trouble with this part of my application:
_btnSubmit.setOnClickListener(
new View.OnClickListener() {
#Override
public void onClick(View v) {
// do something...
}
});
I get the "Unfortunately [app] has stopped working" error.I can't find the problem.
Here's my xml:
<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:tools="http://schemas.android.com/tools"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:paddingBottom="#dimen/activity_vertical_margin"
android:paddingLeft="#dimen/activity_horizontal_margin"
android:paddingRight="#dimen/activity_horizontal_margin"
android:paddingTop="#dimen/activity_vertical_margin"
tools:context="com.example.droidone.MainActivity$PlaceholderFragment" >
<TextView
android:id="#+id/txtAppTitle"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_alignParentTop="true"
android:layout_centerHorizontal="true"
android:layout_marginTop="27dp"
android:text="#string/app_title"
android:textAppearance="?android:attr/textAppearanceLarge" />
<TextView
android:id="#+id/lblInputHeight"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_alignLeft="#+id/lblInputWeight"
android:layout_below="#+id/lblInputWeight"
android:layout_marginTop="34dp"
android:text="#string/input_height"
android:textAppearance="?android:attr/textAppearanceSmall" />
<Button
android:id="#+id/btnSubmit"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_below="#+id/lblInputHeight"
android:layout_centerHorizontal="true"
android:layout_marginTop="46dp"
android:text="#string/btn_getBMI" />
<EditText
android:id="#+id/txtInputHeightFt"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_alignBaseline="#+id/txtInputHeightIn"
android:layout_alignBottom="#+id/txtInputHeightIn"
android:layout_toLeftOf="#+id/txtInputHeightIn"
android:ems="3"
android:inputType="numberDecimal" />
<TextView
android:id="#+id/txtResult"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_alignLeft="#+id/lblInputHeight"
android:layout_alignRight="#+id/txtInputHeightIn"
android:layout_below="#+id/btnSubmit"
android:layout_marginTop="59dp"
android:textAppearance="?android:attr/textAppearanceMedium" />
<TextView
android:id="#+id/lblInputWeight"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_below="#+id/txtAppTitle"
android:layout_marginTop="60dp"
android:layout_toLeftOf="#+id/btnSubmit"
android:text="#string/input_weight"
android:textAppearance="?android:attr/textAppearanceSmall" />
<EditText
android:id="#+id/txtInputWeight"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_above="#+id/lblInputHeight"
android:layout_toLeftOf="#+id/txtInputHeightIn"
android:ems="3"
android:inputType="numberDecimal" >
<requestFocus />
</EditText>
<EditText
android:id="#+id/txtInputHeightIn"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_above="#+id/btnSubmit"
android:layout_alignParentRight="true"
android:ems="3"
android:inputType="numberDecimal" />
</RelativeLayout>
and activity:
package com.example.droidone;
import android.support.v7.app.ActionBarActivity;
import android.support.v7.app.ActionBar;
import android.support.v4.app.Fragment;
import android.os.Bundle;
import android.view.LayoutInflater;
import android.view.Menu;
import android.view.MenuItem;
import android.view.View;
import android.view.ViewGroup;
import android.widget.Button;
import android.widget.EditText;
import android.widget.TextView;
import android.os.Build;
import android.view.View.OnClickListener;
public class MainActivity extends ActionBarActivity {
Button _btnSubmit;
EditText _txtInputWeight;
EditText _txtInputHeightFt;
EditText _txtInputHeightIn;
TextView _txtResult;
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
setUpView();
setUpOnClick();
if (savedInstanceState == null) {
getSupportFragmentManager().beginTransaction()
.add(R.id.container, new PlaceholderFragment())
.commit();
}
}
private void setUpView()
{
_btnSubmit = (Button)findViewById(R.id.btnSubmit);
_txtInputWeight = (EditText)findViewById(R.id.txtInputWeight);
_txtInputHeightFt = (EditText)findViewById(R.id.txtInputHeightFt);
_txtInputHeightIn = (EditText)findViewById(R.id.txtInputHeightIn);
_txtResult = (TextView)findViewById(R.id.txtResult);
}
private void setUpOnClick() {
_btnSubmit = (Button)findViewById(R.id.btnSubmit);
_btnSubmit.setOnClickListener(
new View.OnClickListener() {
#Override
public void onClick(View v) {
// do something...
}
});
}
#Override
public boolean onCreateOptionsMenu(Menu menu) {
// Inflate the menu; this adds items to the action bar if it is present.
getMenuInflater().inflate(R.menu.main, menu);
return true;
}
#Override
public boolean onOptionsItemSelected(MenuItem item) {
// Handle action bar item clicks here. The action bar will
// automatically handle clicks on the Home/Up button, so long
// as you specify a parent activity in AndroidManifest.xml.
int id = item.getItemId();
if (id == R.id.action_settings) {
return true;
}
return super.onOptionsItemSelected(item);
}
/**
* A placeholder fragment containing a simple view.
*/
public static class PlaceholderFragment extends Fragment {
public PlaceholderFragment() {
}
#Override
public View onCreateView(LayoutInflater inflater, ViewGroup container,
Bundle savedInstanceState) {
View rootView = inflater.inflate(R.layout.fragment_main, container, false);
return rootView;
}
}
}
I bet the layout xml is related to the Fragment and not the Activity, try to move both setUpView() and setUpOnClick() into the PlaceholderFragment, like this:
public static class PlaceholderFragment extends Fragment {
Button _btnSubmit;
EditText _txtInputWeight;
EditText _txtInputHeightFt;
EditText _txtInputHeightIn;
TextView _txtResult;
public PlaceholderFragment() {
}
#Override
public View onCreateView(LayoutInflater inflater, ViewGroup container,
Bundle savedInstanceState) {
View rootView = inflater.inflate(R.layout.fragment_main, container, false);
setUpView(rootView);
setUpOnClick(rootView);
return rootView;
}
private void setUpView(View rootView)
{
_btnSubmit = (Button)rootView.findViewById(R.id.btnSubmit);
_txtInputWeight = (EditText)rootView.findViewById(R.id.txtInputWeight);
_txtInputHeightFt = (EditText)rootView.findViewById(R.id.txtInputHeightFt);
_txtInputHeightIn = (EditText)rootView.findViewById(R.id.txtInputHeightIn);
_txtResult = (TextView)rootView.findViewById(R.id.txtResult);
}
private void setUpOnClick(View rootView) {
_btnSubmit = (Button)rootView.findViewById(R.id.btnSubmit);
_btnSubmit.setOnClickListener(
new View.OnClickListener() {
#Override
public void onClick(View v) {
// do something...
}
});
}
}
And just as a piece of advice, try looking into ButterKnife, makes life much easier dealing with injecting views and handling button clicks.
Edit:
Seeing the other answer, I failed to spot that the xml actually is related to the activity. I do think that it is preferred to have all the layout contained in fragments nowadays though. In your case, not doing so leaves the PlaceholderFragment of no use and could might as well be removed entirely.
OK you have the elements in your activity_main.xml layout
but when you do a transaction to PlaceholderFragment() it loads fragment_main.xml and the reference of that elements doesn´t exist!
change your PlaceholderFragment class to:
public static class PlaceholderFragment extends Fragment {
Button _btnSubmit;
EditText _txtInputWeight;
EditText _txtInputHeightFt;
EditText _txtInputHeightIn;
TextView _txtResult;
public PlaceholderFragment() {
}
#Override
public View onCreateView(LayoutInflater inflater, ViewGroup container,
Bundle savedInstanceState) {
View rootView = inflater.inflate(R.layout.fragment_main, container, false);
setUpView(rootView);
setUpOnClick(rootView);
return rootView;
}
private void setUpView(View rootView){
_btnSubmit = (Button)rootView.findViewById(R.id.btnSubmit);
_txtInputWeight = (EditText)rootView.findViewById(R.id.txtInputWeight);
_txtInputHeightFt = (EditText)rootView.findViewById(R.id.txtInputHeightFt);
_txtInputHeightIn = (EditText)rootView.findViewById(R.id.txtInputHeightIn);
_txtResult = (TextView)rootView.findViewById(R.id.txtResult);
}
private void setUpOnClick(View rootView) {
_btnSubmit = (Button)rootView.findViewById(R.id.btnSubmit);
_btnSubmit.setOnClickListener(
new View.OnClickListener() {
#Override
public void onClick(View v) {
// do something :)
}
});
}
}
The problem is that you are trying to add a fragment to R.id.container in the onCreate() method. Your layout does not have this element in it. Remove that code and it should do the trick.
I'm new to android and java. this is my first app. an example of a book. I did all steps according the book. the app is going to increase the number by click on + button
this is my Java file :
package com.example.myprayercounter;
import android.support.v7.app.ActionBarActivity;
import android.support.v7.app.ActionBar;
import android.support.v4.app.Fragment;
import android.os.Bundle;
import android.view.LayoutInflater;
import android.view.Menu;
import android.view.MenuItem;
import android.view.View;
import android.view.ViewGroup;
import android.widget.Button;
import android.widget.TextView;
import android.os.Build;
public class MainActivity extends ActionBarActivity {
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
//
if (savedInstanceState == null) {
getSupportFragmentManager().beginTransaction()
.add(R.id.container, new PlaceholderFragment()).commit();
}
}
#Override
public boolean onCreateOptionsMenu(Menu menu) {
// Inflate the menu; this adds items to the action bar if it is present.
getMenuInflater().inflate(R.menu.main, menu);
return true;
}
#Override
public boolean onOptionsItemSelected(MenuItem item) {
// Handle action bar item clicks here. The action bar will
// automatically handle clicks on the Home/Up button, so long
// as you specify a parent activity in AndroidManifest.xml.
int id = item.getItemId();
if (id == R.id.action_settings) {
return true;
}
return super.onOptionsItemSelected(item);
}
/**
* A placeholder fragment containing a simple view.
*/
public static class PlaceholderFragment extends Fragment {
int counter;
TextView tView;
Button btn;
public PlaceholderFragment() {}
#Override
public View onCreateView(LayoutInflater inflater, ViewGroup container,
Bundle savedInstanceState) {
View rootView = inflater.inflate(R.layout.fragment_main, container, false);
counter = 0;
tView = (TextView)getActivity().findViewById(R.id.txt_textTwo);
btn = (Button)getActivity().findViewById(R.id.btn_buttonOne);
btn.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View v) {
counter++;
tView.setText(" " + counter);
}
});
return rootView;
}
}
}
xml file :
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:tools="http://schemas.android.com/tools"
android:id="#+id/LinearLayout1"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:background="#fbfbdd"
android:gravity="center_horizontal"
android:orientation="vertical"
android:paddingBottom="#dimen/activity_vertical_margin"
android:paddingLeft="#dimen/activity_horizontal_margin"
android:paddingRight="#dimen/activity_horizontal_margin"
android:paddingTop="#dimen/activity_vertical_margin"
tools:context="com.example.myprayercounter.MainActivity$PlaceholderFragment" >
<TextView
android:id="#+id/txt_textOne"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:text="تعداد ذکرهای من"
android:textColor="#763f05"
android:textSize="20dp" />
<TextView
android:id="#+id/txt_textTwo"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:text="0"
android:textColor="#763f05"
android:textSize="40dp" />
<Button
android:id="#+id/btn_buttonOne"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:background="#763f05"
android:text="+"
android:textColor="#fbfbdd"
android:textSize="40dp" />
</LinearLayout>
I got this error at first run of the app :
What is my mistakes? and how i can fix them?
Thanks in advance
change:
tView = (TextView)getActivity().findViewById(R.id.txt_textTwo);
btn = (Button)getActivity().findViewById(R.id.btn_buttonOne);
to ( getActivity() --> rootView)
tView = (TextView)rootView.findViewById(R.id.txt_textTwo);
btn = (Button)rootView.findViewById(R.id.btn_buttonOne);
in PlaceholderFragment, your View is rootView and you need find your view from that