Android button click event four common writing methods, android four

Android button click event four common writing methods, android four

The xml layout is as follows:

<Button    android:id="@+id/button1"    android:layout_width="wrap_content"    android:layout_height="wrap_content"    android:text="Button1" />   <Button    android:id="@+id/button2"    android:layout_width="wrap_content"    android:layout_height="wrap_content"    android:text="Button2" />

First: anonymous internal class

Applicable scenarios: ---------------------------------------------------------- test or single button

public class TestButtonActivity extends Activity {   Button btn1, btn2;  Toast tst;   @Override  protected void onCreate(Bundle savedInstanceState) {    super.onCreate(savedInstanceState);    setContentView(R.layout.activity_test_button);     btn1 = (Button) findViewById(R.id.button1);    btn2 = (Button) findViewById(R.id.button2);     btn1.setOnClickListener(new OnClickListener() {       @Override      public void onClick(View v) {        // TODO Auto-generated method stub        Toast tst = Toast.makeText(TestButtonActivity.this, "111111111", Toast.LENGTH_SHORT);        tst.show();       }    });     btn2.setOnClickListener(new OnClickListener() {       @Override      public void onClick(View v) {        // TODO Auto-generated method stub        Toast tst = Toast.makeText(TestButtonActivity.this, "222222222", Toast.LENGTH_SHORT);        tst.show();      }    });  }}

The second type of custom click event listening class:

Rarely used!

public class TestButtonActivity extends Activity {   Button btn1, btn2;  Toast tst;   class MyClickListener implements OnClickListener {     @Override    public void onClick(View v) {      // TODO Auto-generated method stub      switch (v.getId()) {      case R.id.button1:        tst = Toast.makeText(TestButtonActivity.this, "111111111", Toast.LENGTH_SHORT);        tst.show();        break;      case R.id.button2:        tst = Toast.makeText(TestButtonActivity.this, "222222222", Toast.LENGTH_SHORT);        tst.show();        break;      default:        break;      }    }  }   @Override  protected void onCreate(Bundle savedInstanceState) {    super.onCreate(savedInstanceState);    setContentView(R.layout.activity_test_button);     btn1 = (Button) findViewById(R.id.button1);    btn2 = (Button) findViewById(R.id.button2);     btn1.setOnClickListener(new MyClickListener());    btn2.setOnClickListener(new MyClickListener());  }}

The third type of Activity inherits View. OnClickListener, and The OnClick (View view) method is implemented by the Activity. In The OnClick (View view) method, switch-case is used to process the buttons represented by different IDs.

~~~~~~~~~~~~~~~ · It is often used. It is generally used when there are many buttons ~~~~~~~~~~ ·····

public class TestButtonActivity extends Activity implements OnClickListener {   Button btn1, btn2;  Toast tst;   @Override  protected void onCreate(Bundle savedInstanceState) {    super.onCreate(savedInstanceState);    setContentView(R.layout.activity_test_button);     btn1 = (Button) findViewById(R.id.button1);    btn2 = (Button) findViewById(R.id.button2);     btn1.setOnClickListener(this);    btn2.setOnClickListener(this);  }   @Override  public void onClick(View v) {    // TODO Auto-generated method stub    switch (v.getId()) {    case R.id.button1:      tst = Toast.makeText(this, "111111111", Toast.LENGTH_SHORT);      tst.show();      break;    case R.id.button2:      tst = Toast.makeText(this, "222222222", Toast.LENGTH_SHORT);      tst.show();      break;    default:      break;    }  }}

Fourth, you do not need to set the Click Event in The Onclick Event code.

Public class TestButtonActivity extends Activity {Button btn1, btn2; Toast tst; @ Override protected void onCreate (Bundle savedInstanceState) {super. onCreate (savedInstanceState); setContentView (R. layout. activity_test_button);} // note that there is no @ Override label public void onClick (View v) {// TODO Auto-generated method stub switch (v. getId () {case R. id. button1: tst = Toast. makeText (this, "111111111", Toast. LENGTH_SHORT); tst. show (); break; case R. id. button2: tst = Toast. makeText (this, "222222222", Toast. LENGTH_SHORT); tst. show (); break; default: break ;}}}