add onclick listener to predefined button?
You can try this.
public class myNewClass extends Activity implements OnClickListener {
...................
...................
Button button = (Button)findViewById(R.id.button1);
button.setOnClickListener(this);
public void onClick(View v) {
Intent i = new Intent();
Bundle extras = new Bundle();
// This will catch the button click
// Now do what you wanted to do as a
// result of the onClick
}
}
You just need something like this:
Button buttonOne = (Button) findViewById(R.id.button1);
buttonOne.setOnClickListener(new Button.OnClickListener() {
public void onClick(View v) {
//Do stuff here
}
});
This answer comes from Five Ways to Wire Up an Event Listener. Please read that blog post for a fuller explanation from the author. See my other answer for these five ways reworked to add multiple onClick listeners.
1. Member Class
public class main extends Activity {
@Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.main);
//attach an instance of HandleClick to the Button
findViewById(R.id.button1).setOnClickListener(new HandleClick());
}
private class HandleClick implements OnClickListener{
public void onClick(View arg0) {
Button btn = (Button)arg0; //cast view to a button
// get a reference to the TextView
TextView tv = (TextView) findViewById(R.id.textview1);
// update the TextView text
tv.setText("You pressed " + btn.getText());
}
}
}
2. Interface Type
public class main extends Activity {
@Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.main);
//use the handleClick variable to attach the event listener
findViewById(R.id.button1).setOnClickListener(handleClick);
}
private OnClickListener handleClick = new OnClickListener(){
public void onClick(View arg0) {
Button btn = (Button)arg0;
TextView tv = (TextView) findViewById(R.id.textview1);
tv.setText("You pressed " + btn.getText());
}
};
}
3. Anonymous Inner Class
public class main extends Activity {
@Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.main);
findViewById(R.id.button1).setOnClickListener(new OnClickListener(){
public void onClick(View arg0) {
Button btn = (Button)arg0;
TextView tv = (TextView) findViewById(R.id.textview1);
tv.setText("You pressed " + btn.getText());
}
});
}
}
4. Implementation in Activity
public class main extends Activity implements OnClickListener{
@Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.main);
findViewById(R.id.button1).setOnClickListener(this);
}
public void onClick(View arg0) {
Button btn = (Button)arg0;
TextView tv = (TextView) findViewById(R.id.textview1);
tv.setText("You pressed " + btn.getText());
}
}
5. Attribute in View Layout for OnClick Events
public class main extends Activity{
@Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.main);
}
public void HandleClick(View arg0) {
Button btn = (Button)arg0;
TextView tv = (TextView) findViewById(R.id.textview1);
tv.setText("You pressed " + btn.getText());
}
}
xml:
<Button android:id="@+id/button1"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:text="Button 1"
android:onClick="HandleClick"/>