I am new to android development.I am trying to create an activity method on clicking a button.
Below is my MainActivity.java file code.
I am getting errors
1."cannot resolve method'setVisibility (int)'" and
2."cannot resolve symbol 'TextView'"
please guide.
MainActivity.java
package com.AndroidLove;
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;
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();
}
}
public void onLoveButtonClicked(View view) {
TextView textView =(TextView) findViewById(R.id.textView);
textView.setVisibility(View.VISIBLE);
}
#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.
switch (item.getItemId()) {
case 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;
}
}
}
Import this package as well
import android.widget.TextView;
Related
How can i switch activity using Button? this is my problem:
package net.example.finals;
import android.support.v7.app.ActionBarActivity;
import android.support.v7.app.ActionBar;
import android.support.v4.app.Fragment;
import android.content.Intent;
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.AdapterView;
import android.widget.Button;
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 implements OnClickListener {
Button bq;
Button bw;
Button be;
Button br;
Button bt;
Button by;
Button bu;
public PlaceholderFragment() {
}
#Override
public View onCreateView(LayoutInflater inflater, ViewGroup container,
Bundle savedInstanceState) {
View rootView = inflater.inflate(R.layout.fragment_second,
container, false);
bq=(Button)rootView.findViewById(R.id.btn1);
bq.setOnClickListener(this);
bw=(Button)rootView.findViewById(R.id.btn2);
bw.setOnClickListener(this);
be=(Button)rootView.findViewById(R.id.btn3);
be.setOnClickListener(this);
br=(Button)rootView.findViewById(R.id.btn4);
br.setOnClickListener(this);
bt=(Button)rootView.findViewById(R.id.btn5);
bt.setOnClickListener(this);
by=(Button)rootView.findViewById(R.id.btn6);
by.setOnClickListener(this);
bu=(Button)rootView.findViewById(R.id.btn7);
bu.setOnClickListener(this);
return rootView;
}
#Override
public void onClick(View v) {
// TODO Auto-generated method stub
//i dont know what to put here
case R.id.btn1:
if(bq.callOnClick()==true){
Intent myOwnIntent = new Intent(getActivity(), Second.class);
startActivity(myOwnIntent);
}
break;
}
}
}
Why did you use "if(bq.callOnClick()==true)" this?
Android use a lots of java code, first you need to learn java properly.
AND Google too
#Override
public void onClick(View v) {
int id = v.getId();
switch(id){
case R.id.btn1:
Intent myOwnIntent = new Intent(YourActivityName.this, Second.class);
startActivity(myOwnIntent);
break;
}
}
Try this one.
How to start new activity on button click
Start another activity by clicking a button
Android eclipse how to start a new activity on button click
Trying to create a switch in android with default ON state and with OnCheckedChangeListener. But application is force closing. What is wrong? please help. New in android development.
package com.tiumca2013.smarthousecontrol;
import android.app.Activity;
import android.app.Fragment;
import android.bluetooth.BluetoothAdapter;
import android.content.Context;
import android.content.Intent;
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.CompoundButton;
import android.widget.CompoundButton.OnCheckedChangeListener;
import android.widget.Switch;
import android.widget.Toast;
public class MainActivity extends Activity{
private Switch switch1;
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
switch1 = (Switch) findViewById(R.id.Switch1);
switch1.setChecked(true); // force close
switch1.setOnCheckedChangeListener(new OnCheckedChangeListener() // force close again
{
#Override
public void onCheckedChanged(CompoundButton buttonView, boolean isChecked)
{
if(isChecked)
Toast.makeText(getApplicationContext(),"switch 1 ON",Toast.LENGTH_SHORT).show();
else
Toast.makeText(getApplicationContext(),"switch 1 OFF",Toast.LENGTH_SHORT).show();
}
});
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;
}
}
}
I can't understand why this simple code is not working.
This code suppose to set the color of the button's text to blue, that's all.
I only added to a new created project the lines :
final Button btn = (Button) findViewById(R.id.button1);
btn.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View v) {
// Perform action on click
btn.setTextColor(Color.BLUE);
}
});
The full code :
package com.example.b;
import android.graphics.Color;
import android.os.Bundle;
import android.support.v4.app.Fragment;
import android.support.v7.app.ActionBarActivity;
import android.view.LayoutInflater;
import android.view.Menu;
import android.view.MenuItem;
import android.view.View;
import android.view.ViewGroup;
import android.widget.Button;
public class MainActivity extends ActionBarActivity {
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
final Button btn = (Button) findViewById(R.id.button1);
btn.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View v) {
// Perform action on click
btn.setTextColor(Color.BLUE);
}
});
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 {
public PlaceholderFragment() {
}
#Override
public View onCreateView(LayoutInflater inflater, ViewGroup container,
Bundle savedInstanceState) {
View rootView = inflater.inflate(R.layout.fragment_main, container, false);
return rootView;
}
}
}
Most likely the button is in the fragment and not the activity. If so, move your findViewById and your setonclick code into your PlaceHolderFragment.
I dont know what happen with my sdk and eclipse. I install google services,it is install successfully but now i add activity to my old project but now .java file is extends FragementActivity. i dont know why this is happen. Please give reply please.
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;
public class WebViewActivity extends ActionBarActivity {
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.web_view);
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.web_view, 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 can't to get the button from fragment, what's wrong?
Recieve a uncaught exception - nullpointerexception;
Button can't be found.
Early all will be find, but after update android sdk, all is changed ((
package com.example.test;
import java.io.IOException;
import android.media.MediaPlayer;
import android.os.Bundle;
import android.support.v4.app.Fragment;
import android.support.v7.app.ActionBarActivity;
import android.util.Log;
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.RadioButton;
import android.widget.RadioGroup;
import android.widget.Toast;
public class MainActivity extends ActionBarActivity implements OnClickListener {
Button play, pause;
MediaPlayer mplayer;
RadioGroup rgroup;
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
Log.i("MyTAG", "1");
if (savedInstanceState == null) {
getSupportFragmentManager().beginTransaction()
.add(R.id.container, new PlaceholderFragment()).commit();
}
mplayer = new MediaPlayer();
rgroup = (RadioGroup) findViewById(R.id.radioGroup1);
play = (Button) findViewById(R.id.play);
pause = (Button) findViewById(R.id.pause);
play.setOnClickListener(this);
pause.setOnClickListener(this);
}
#Override
public void onClick(View v) {
}
#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;
}
}
}
p.s. sorry for my english
You are trying to search inside Activity's layout, and your widgets are inside a Fragment's layout.
Put your logic inside your PlaceHolderFragment class:
public static class PlaceholderFragment extends Fragment implements OnClickListener {
public PlaceholderFragment() {
}
#Override
public View onCreateView(LayoutInflater inflater, ViewGroup container,
Bundle savedInstanceState) {
View rootView = inflater.inflate(R.layout.fragment_main, container,
false);
mplayer = new MediaPlayer();
rgroup = (RadioGroup) rootView.findViewById(R.id.radioGroup1);
play = (Button) rootView.findViewById(R.id.play);
pause = (Button) rootView.findViewById(R.id.pause);
play.setOnClickListener(this);
pause.setOnClickListener(this);
return rootView;
}
#Override
public void onClick(View v) {
}
}
P.S. Салам алейкум =)