import android.support.v4.app.Fragment;
import android.app.Activity;
import android.app.Dialog;
import android.content.Context;
import android.os.Bundle;
import android.view.LayoutInflater;
import android.view.Menu;
import android.view.MenuItem;
import android.view.MotionEvent;
import android.view.View;
import android.view.View.OnTouchListener;
import android.view.ViewGroup;
import android.view.View.OnClickListener;
import android.view.inputmethod.InputMethodManager;
import android.widget.*;
import android.widget.NumberPicker.OnValueChangeListener;
public class MainActivity extends Activity implements OnValueChangeListener {
EditText push_ups, sit_ups;
NumberPicker np;
Button calculate;
final Context context = this;
CheckBox checkbox;
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
calculate = (Button)findViewById(R.id.calculate);
push_ups = (EditText)findViewById(R.id.pushups);
sit_ups = (EditText)findViewById(R.id.situps);
np = (NumberPicker)findViewById(R.id.np1);
checkbox = (CheckBox)findViewById(R.id.checkbox);
String[] values = {"some array"};
np.setMaxValue(values.length-1);
np.setMinValue(0);
np.setDisplayedValues(values);
np.setWrapSelectorWheel(false);
//calculateButton runs when I click the "calculate" Button
calculateButton();
LinearLayout layout = (LinearLayout)findViewById(R.id.linearLayout1);
layout.setOnTouchListener(new OnTouchListener() {
#Override
public boolean onTouch(View v, MotionEvent event) {
hideKeyboard();
return false;
}
});
}
#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 onValueChange(NumberPicker picker, int oldVal, int newVal) {
}
private void hideKeyboard() {
InputMethodManager imm = (InputMethodManager)context.getSystemService(Context.INPUT_METHOD_SERVICE);
imm.hideSoftInputFromWindow(push_ups.getWindowToken(), 0);
}
public int calculatePushups() {
int pushupScore = 0;
int ageGroup = Integer.parseInt(null, np.getValue());
int pushupReps = Integer.parseInt(push_ups.getText().toString());
final int [][] pushupTable = {"some 2D array"};
if (pushupReps<= 60) {
pushupScore = pushupTable[pushupReps][ageGroup];
} else {
pushupScore = 60;
}
return pushupScore;
}
public int calculateSitups() {
final int [][] situpTable = {"some 2D array"};
return 0;
}
private void normalRun() {
}
private void specialRun() {
}
private void calculateRun() {
if (checkbox.isChecked()) {
specialRun();
}
else {
normalRun();
}
}
private void calculateScore() {
calculatePushups();
calculateSitups();
calculateRun();
}
public void calculateButton() {
final TextView pus = (TextView)findViewById(R.id.pushup_score);
calculate.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View v) {
// custom dialog
final Dialog dialog = new Dialog(context);
dialog.setContentView(R.layout.dialog_custom);
dialog.setTitle("Score");
I am trying to set the TextView to display the pushupScore here but it seems I am trying to pass a result from another method to this. I have no idea how to get it around still new with android,
//pus.setText(pushupScore);
pus.setText(String.valueOf(calculatePushups()));
Button dialogButton = (Button) dialog.findViewById(R.id.dialog_ok);
// if button is clicked, close the custom dialog
dialogButton.setOnClickListener(new OnClickListener() {
#Override
public void onClick(View v) {
dialog.dismiss();
}
});
dialog.show();
}
});
}
}
Here's my dialog XML code:
<LinearLayout
android:layout_width="wrap_content"
android:layout_height="wrap_content" >
<TextView
android:id="#+id/textView1"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:lineSpacingExtra="5dp"
android:text="Push-ups: "
android:textAppearance="?android:attr/textAppearanceMedium" />
<TextView
android:id="#+id/pushup_score"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_weight="4.97"
android:textAppearance="?android:attr/textAppearanceMedium" />
</LinearLayout>
<TextView
android:id="#+id/textView2"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:lineSpacingExtra="5dp"
android:text="Sit-ups: "
android:textAppearance="?android:attr/textAppearanceMedium" />
<TextView
android:id="#+id/textView3"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:lineSpacingExtra="5dp"
android:text="2.4km Run: "
android:textAppearance="?android:attr/textAppearanceMedium" />
<TextView
android:id="#+id/textView4"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:lineSpacingExtra="5dp"
android:text="Award: "
android:textAppearance="?android:attr/textAppearanceLarge" />
<Button
android:id="#+id/dialog_ok"
style="#style/AppTheme"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_gravity="center_horizontal"
android:lineSpacingExtra="5dp"
android:text="Ok" />
</LinearLayout>
you are returning the pushupScore in calculatePushups so just write:
pus.setText(String.valueOf(calculatePushups()));
And btw this is not a android mechanism, this is simple java return usage:
http://docs.oracle.com/javase/tutorial/java/javaOO/returnvalue.html
You left out quite a bit of your code so I'm not sure where your problem is, but if you could follow these steps and let me know if you're getting any errors etc? Anyway, here is what you need to have:
Make sure your Activity implements OnClickListener:
public class MainActivity extends Activity implements OnClickListener, OnValueChangeListener {
//...
}
Within the activity's overridden onCreate() method, register the activity as the handler:
calculate = (Button)v.findViewById(R.id.dialog_ok);
calculate.setOnClickListener(this);
Within MainActivity, have the handler like so:
public void onClick(View v){
switch(v.getId(){
case R.id.dialog_ok:
push_ups.setText("" + calculatePushups());
break;
}
// ...
}
Perhaps you should change your EditText into a TextView, the EditText isn't necessary and might be causing problems?
Is this what you were after?
Related
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
I have an Android application with a very simple main activity. It only has two buttons, one textview and one edittext field. I launch the main activity (I don't do anything, just launch it from app drawer), then I press home button to get to my home screen, go to settings > appmanager > running > cached background processes and there I see that my app is eating more RAM than other cached background processes, around 8 MB of RAM. Is it normal? Why is it eating more than other apps? This is my code:
MainActivity:
package com.example.myapp;
import android.app.ActivityManager;
import android.content.ComponentName;
import android.content.Intent;
import android.content.pm.PackageManager;
import android.os.Bundle;
import android.support.v4.app.Fragment;
import android.support.v7.app.ActionBarActivity;
import android.telephony.TelephonyManager;
import android.util.Log;
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;
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();
}
ActivityManager am = (ActivityManager) getSystemService(ACTIVITY_SERVICE);
int memoryClass = am.getMemoryClass();
long maxMemory = Runtime.getRuntime().maxMemory();
long totalMemory = Runtime.getRuntime().totalMemory();
Log.i("ilog", "memoryClass: " + memoryClass);
Log.i("ilog", "maxMemory: " + maxMemory);
Log.i("ilog", "totalMemory: " + totalMemory);
}
#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 {
private Button button1;
private Button button2;
private TextView textView1;
private EditText editText1;
private ComponentName cn;
private String disable = "Disable app";
private String enable = "Enable app";
private int enabledState;
private PackageManager pm;
public PlaceholderFragment() {
}
#Override
public View onCreateView(LayoutInflater inflater, ViewGroup container,
Bundle savedInstanceState) {
View rootView = inflater.inflate(R.layout.fragment_main, container, false);
button1 = (Button) rootView.findViewById(R.id.button1);
editText1 = (EditText) rootView.findViewById(R.id.editText1);
textView1 = (TextView) rootView.findViewById(R.id.textView1);
button2 = (Button) rootView.findViewById(R.id.button2);
cn = new ComponentName(getActivity(), CallReceiver.class);
pm = getActivity().getPackageManager();
enabledState = pm.getComponentEnabledSetting(cn);
if (enabledState == PackageManager.COMPONENT_ENABLED_STATE_ENABLED) {
button1.setText(disable);
} else {
button1.setText(enable);
}
button1.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View v) {
enabledState = pm.getComponentEnabledSetting(cn);
if (enabledState == PackageManager.COMPONENT_ENABLED_STATE_ENABLED) {
pm.setComponentEnabledSetting(cn,
PackageManager.COMPONENT_ENABLED_STATE_DISABLED,
PackageManager.DONT_KILL_APP);
button1.setText(enable);
} else {
pm.setComponentEnabledSetting(cn,
PackageManager.COMPONENT_ENABLED_STATE_ENABLED,
PackageManager.DONT_KILL_APP);
button1.setText(disable);
}
}
});
button2.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View v) {
if (editText1.getText().toString().length() > 0) {
Intent callImitateIntent = new Intent(getActivity(), CallReceiver.class);
callImitateIntent.putExtra(TelephonyManager.EXTRA_STATE, TelephonyManager.EXTRA_STATE_RINGING);
callImitateIntent.putExtra(TelephonyManager.EXTRA_INCOMING_NUMBER, editText1.getText().toString());
getActivity().sendBroadcast(callImitateIntent);
} else textView1.setText("Invalid incoming number");
}
});
return rootView;
}
}
#Override
public void onDestroy() {
super.onDestroy();
Intent serviceStopIntent = new Intent(this, WindowService.class);
stopService(serviceStopIntent);
}
}
fragment_main.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.myapp.MainActivity$PlaceholderFragment" >
<TextView
android:id="#+id/textView1"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_alignParentTop="true"
android:layout_centerHorizontal="true"
android:text="#string/welcome" />
<Button
android:id="#+id/button1"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_below="#+id/textView1"
android:layout_centerHorizontal="true"
android:layout_marginTop="20dp" />
<EditText
android:id="#+id/editText1"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_below="#+id/button1"
android:layout_centerHorizontal="true"
android:layout_marginTop="30dp"
android:maxLength="12"
android:hint="#string/edittext1" />
<Button
android:id="#+id/button2"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_below="#+id/editText1"
android:layout_centerHorizontal="true"
android:layout_marginTop="30dp"
android:text="#string/button2" />
</RelativeLayout>
So can anyone tell me why is it eating so much RAM? Thanks in advance!
I am new to Android, so please forgive my ignorance. I have tried searching the forums, but haven't been able to find anything to get this to work. I am trying to use .getText().toString() (see below), but get a java.lang.NullPointerException error. I changed my setContentView so that it would look at the fragment_main.xml, but still returns a null for my different components. The goal of this is very simple, just to change the text on the TextView, since I am just getting started. Any help would be appreciated.
package com.example.app;
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.os.Build;
import android.widget.Button;
import android.widget.TextView;
public class MainActivity extends ActionBarActivity {
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.fragment_main);
if (savedInstanceState == null) {
getSupportFragmentManager().beginTransaction()
.add(R.id.container, new PlaceholderFragment())
.commit();
}
Button changeTxt = (Button) findViewById(R.id.btnChangeText);
final TextView textView = (TextView) findViewById(R.id.txtMessage);
changeTxt.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View view) {
String text = textView.getText().toString();
if (text.contains("World")) {
textView.setText("Hello Android!");
}
else {
textView.setText(("Hello World!"));
}
}
});
}
public void onStart(){
super.onStart();
}
public void onResume(){
super.onResume();
}
public void onPause(){
super.onPause();
}
public void onStop(){
super.onStop();
}
public void onDestroy(){
super.onDestroy();
}
#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;
}
}
}
Here is the xml:
<LinearLayout
android:orientation="vertical"
android:layout_width="fill_parent"
android:layout_height="fill_parent"
xmlns:android="http://schemas.android.com/apk/res/android">
<TextView
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:textAppearance="?android:attr/textAppearanceLarge"
android:text="Large Text"
android:id="#+id/txtMessage"
android:layout_gravity="center_horizontal" />
<Button
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:text="Change Text"
android:id="#+id/btnChangeText"
android:layout_gravity="center_horizontal" />
</LinearLayout>
Fllo, updated code:
XML fragment_main.xml
<LinearLayout
android:orientation="vertical"
android:layout_width="fill_parent"
android:layout_height="fill_parent"
xmlns:android="http://schemas.android.com/apk/res/android">
<FrameLayout
android:layout_width="match_parent"
android:layout_height="match_parent">
<TextView
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:textAppearance="?android:attr/textAppearanceLarge"
android:text="Large Text"
android:id="#+id/txtMessage1"
android:layout_gravity="center_horizontal" />
<Button
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:text="Change Text"
android:id="#+id/btnChangeText1"
android:layout_gravity="center" />
</FrameLayout>
</LinearLayout>
main activity
package com.example.app;
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.os.Build;
import android.widget.Button;
import android.widget.TextView;
public class MainActivity extends ActionBarActivity {
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.fragment_main);
if (savedInstanceState == null) {
getSupportFragmentManager().beginTransaction()
.add(R.id.container, new PlaceholderFragment())
.commit();
}
}
public void onStart(){
super.onStart();
}
public void onResume(){
super.onResume();
}
public void onPause(){
super.onPause();
}
public void onStop(){
super.onStop();
}
public void onDestroy(){
super.onDestroy();
}
#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);
Button changeTxt = (Button) findViewById(R.id.btnChangeText);
final TextView textView = (TextView) findViewById(R.id.txtMessage);
changeTxt.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View view)
{
String text = textView.getText().toString();
if (text.contains("World"))
{
textView.setText("Hello Android!");
}
else
{
textView.setText(("Hello World!"));
}
}
});
return rootView;
}
}
}
The NullPointerException occurs because, it seems that you have the same layout for your Activity and your Fragment:
// Activity
setContentView(R.layout.fragment_main);
// Fragment
View rootView = inflater.inflate(R.layout.fragment_main, container, false);
return rootView;
You need to check if your views (TextView & Button) are in the right layout and not into aonther (I guess activity_main).
Two solutions:
Copy/past your views inside fragment_main to activity_main and change setContentView(R.layout.activity_main).
Or let your views inside fragment_main and use the following code to find your view inside your Fragment, as follows:
#Override
public View onCreateView(LayoutInflater inflater, ViewGroup container,
Bundle savedInstanceState) {
View rootView = inflater.inflate(R.layout.fragment_main, container, false);
Button changeTxt = (Button) rootView.findViewById(R.id.btnChangeText);
final TextView textView = (TextView) rootView.findViewById(R.id.txtMessage);
changeTxt.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View view) {
String text = textView.getText().toString();
if (text.contains("World")) {
textView.setText("Hello Android!");
}
else {
textView.setText(("Hello World!"));
}
}
});
return rootView;
}
Hope this helps.
UPDATE:
1 . Remove your FrameLayout inside fragment_main. Create a new layout named activity_main and add the FrameLayout into it (with an id) as:
<FrameLayout
xmlns:android="http://schemas.android.com/apk/res/android"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:id="#+id/container" />
2 . Set this layout in onCreate method into your Activity like:
// onCreate method Activity
setContentView(R.layout.activity_main);
3 . Then, remove static in your Fragment declaration, this should be:
public class PlaceholderFragment ... { }
4 . Finally, when you try to find ids elements inside onCreateView method, you ALWAYS MUST to use the inflated view as:
rootView.findViewById(R.id.some_id_example);
Voila! This should work now.