Generic receiver for buttons in android layout?

Question

Scenario: I have three buttons defined in xml

<button android:id="@+id/firstbtn" ... /> <button android:id="@+id/secbtn" ... /> <button android:id="@+id/thirdbtn" ... /> 

  In Java one way to listen to them is  
 Button firstbtn = (Button) findViewById (R.id.firstbtn);  
     firstbtn.setOnClickListener (new View.OnClickListener () {  
             public void onClick (View v) {  
                 Toast.makeText (getBaseContext (),   
                         "You have clicked first button",   
                         Toast.LENGTH_SHORT) .show ();  
             }  
         });  

for the second btn, should the same code be repeated with a different id?
How can I make this general enough so that it can listen to all the buttons (e.g. in a loop), and during processing I should be able to distinguish between different btns. (maybe get id element)

Answer 1

Instead of a huge set of calls to findViewById I rather like to use the onClick="methodName" xml attribute. For instance:

 <LinearLayout ...> <Button android:text="1" onClick="onButtonClicked" clickable="true" /> <Button android:text="2" onClick="onButtonClicked" clickable="true" /> <Button android:text="3" onClick="onButtonClicked" clickable="true" /> <Button android:text="4" onClick="onButtonClicked" clickable="true" /> </LinearLayout> 

In the action where the layout is displayed, just add a method

 public void onButtonClicked(View v){ // do whatever needs to be done. For example: Toast.makeText(getApplicationContext(), ((Button) v).getText() + " clicked", Toast.LENGTH_SHORT).show(); } 

You can also put the onClick and clickable attributes in the res / styles.xml file to save even more input:

 <?xml version="1.0" encoding="UTF-8" ?> <resources> <style name="clickable_button" > <item name="android:onClick" >onButtonClicked</item> <item name="android:clickable" >true</item> </style> </resources> 

Then your layout is simplified to

 <LinearLayout ...> <Button android:text="1" style="@style/clickable_button" /> <Button android:text="2" style="@style/clickable_button" /> <Button android:text="3" style="@style/clickable_button" /> <Button android:text="4" style="@style/clickable_button" /> </LinearLayout> 

Answer 2

You do not need to repeat the same code for everyone. You can try the general receiver, for example:

 private OnClickListener mCorkyListener = new OnClickListener() { public void Click(View v) { // do something } }; 

Then you just need to register all three buttons to use this mCorkyListener. That is, inside onCreate (),

 Button firstbtn = (Button) findViewById(R.id.firstbtn); Button secondbtn = (Button) findViewById(R.id.secondbtn); Button thirdbtn = (Button) findViewById(R.id.thirdbtn); firstbtn.setOnClickListener(mCorkyListener); secondbtn.setOnClickListener(mCorkyListener); thirdbtn.setOnClickListener(mCorkyListener); 

Answer 3

Look here for sample code. You must use findViewById to “find” your buttons.