Android----點擊事件的四種寫法

1. • 所有的圖形化操作的應用程序
   • • 全部都是死循環
     • 循環的檢測消息的到來
     • 後臺一直監視着系統的各種消息
     • 基於事件的回調

     
     

2. 四種寫法

   • • 佈局文件中設置onclick屬性
     • 自定義listener

       1. public class MainActivity extends Activity {
       3. @Override
       4. protected void onCreate(Bundle savedInstanceState) {
       5. super.onCreate(savedInstanceState);
       6. setContentView(R.layout.activity_main);
       8. Button button1 = (Button) findViewById(R.id.button1);
       10. MyOnclickListener listener = new MyOnclickListener();
       12. button1.setOnClickListener(listener);
       13. }
       15. class MyOnclickListener implements OnClickListener {
       17. @Override
       18. public void onClick(View v) {
       19. Toast.makeText(MainActivity.this, "hhaa", Toast.LENGTH_LONG).show();
       20. }
       22. }
       23. }
       
       
     • 匿名內部類

       1. public class MainActivity extends Activity {
       3. @Override
       4. protected void onCreate(Bundle savedInstanceState) {
       5. super.onCreate(savedInstanceState);
       6. setContentView(R.layout.activity_main);
       7. Button button1=(Button) findViewById(R.id.button1);
       8. button1.setOnClickListener(new OnClickListener() {
       10. @Override
       11. public void onClick(View v) {
       12. Toast.makeText(MainActivity.this, "匿名內部類", Toast.LENGTH_LONG).show();
       14. }
       15. });
       16. }
       
       
     • MainActivity繼承listener

       1. public class MainActivity extends Activity implements OnClickListener {
       3. private Button button1;
       5. @Override
       6. protected void onCreate(Bundle savedInstanceState) {
       7. super.onCreate(savedInstanceState);
       8. setContentView(R.layout.activity_main);
       10. button1 = (Button) findViewById(R.id.button1);
       11. Button button2 = (Button) findViewById(R.id.button2);
       12. Button button3 = (Button) findViewById(R.id.button3);
       13. Button button4 = (Button) findViewById(R.id.button4);
       14. Button button5 = (Button) findViewById(R.id.button5);
       16. button1.setOnClickListener(this);
       17. button2.setOnClickListener(this);
       18. button3.setOnClickListener(this);
       19. button4.setOnClickListener(this);
       20. button5.setOnClickListener(this);
       21. }
       23. @Override
       24. public void onClick(View v) {
       26. int id = v.getId();
       27. switch (id) {
       28. case R.id.button1:
       29. Toast.makeText(this, "第1個按鈕被點擊了", Toast.LENGTH_SHORT).show();
       30. break;
       31. case R.id.button2:
       32. Toast.makeText(this, "第2個按鈕被點擊了", Toast.LENGTH_SHORT).show();
       33. break;
       34. case R.id.button3:
       35. Toast.makeText(this, "第3個按鈕被點擊了", Toast.LENGTH_SHORT).show();
       36. break;
       37. case R.id.button4:
       38. Toast.makeText(this, "第4個按鈕被點擊了", Toast.LENGTH_SHORT).show();
       39. break;
       40. case R.id.button5:
       41. Toast.makeText(this, "第5個按鈕被點擊了", Toast.LENGTH_SHORT).show();
       42. break;
       44. }
       45. }
       47. }