玩转Android

事件就是用户与UI界面的交互时所触发的操作。比如点击某一个按钮，会触发一个事件等

1、最长用的按钮事件：OnClickListener

     mybutton = (Button)findViewById(R.id.mybutton);
     mybutton.setOnClickListener(new Button.OnClickListener()
     {

@Override
public void onClick(View arg0) {
    // TODO Auto-generated method stub
    ShowMessage("点击了Button按钮");
}

     });

 

 

 

2、我们还可以自定义KeyEvent，比如

public boolean onKeyDown(int keyCode, KeyEvent event)
{
    /**
     * 这里构建KeyEvent对象，功能为返回键的功能
     * 即我们按任意键都是返回键功能
     */
    KeyEvent key = new KeyEvent(KeyEvent.ACTION_DOWN, KeyEvent.KEYCODE_BACK);
    return super.onKeyDown(keyCode, event);
}

 

 

 

3、手机按键的事件处理

Boolean onKeyDown(int keyCode, KeyEvent event)：相应按键按下

Boolean onKeyUp(int keyCode, KeyEvent event)：相应按键释放

Boolean onKeyMultiple()：相应按键重复点击

Boolean onTouchEvent(MotionEvent event)：相应触屏事件

 

package org.hualang.eventtest01;

import android.app.Activity;
import android.os.Bundle;
import android.view.KeyEvent;
import android.view.MotionEvent;
import android.view.View;
import android.widget.Button;
import android.widget.Toast;

public class EventTest01 extends Activity {
    /**
     * 注意，要重写onKeyDown,onKeyUp,onTouchEvent方法
     */
    private Button mybutton;
    @Override
    public void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.main);
        mybutton = (Button)findViewById(R.id.mybutton);
        mybutton.setOnClickListener(new Button.OnClickListener()
        {

            @Override
            public void onClick(View arg0) {
                // TODO Auto-generated method stub
                ShowMessage("点击了Button按钮");
            }

        });

    }
    /**按键按下触发的事件*/
    public boolean onKeyDown(int keyCode, KeyEvent event)
    {
        switch(keyCode)
        {
        case KeyEvent.KEYCODE_DPAD_CENTER:
            ShowMessage("按下:中键");break;
        case KeyEvent.KEYCODE_DPAD_UP:
            ShowMessage("按下:上方向键");break;
        case KeyEvent.KEYCODE_DPAD_DOWN:
            ShowMessage("按下:下方向键");break;
        case KeyEvent.KEYCODE_DPAD_LEFT:
            ShowMessage("按下:左方向键");break;
        case KeyEvent.KEYCODE_DPAD_RIGHT:
            ShowMessage("按下:右方向键");break;
        }
        return super.onKeyDown(keyCode, event);
    }

    /**按键弹起所触发的事件*/
    public boolean onKeyUp(int keyCode, KeyEvent event)
    {
        switch(keyCode)
        {
        case KeyEvent.KEYCODE_DPAD_CENTER:
            ShowMessage("弹起:中键");
            break;
        case KeyEvent.KEYCODE_DPAD_DOWN:
            ShowMessage("弹起:下方向键");
            break;
        case KeyEvent.KEYCODE_DPAD_UP:
            ShowMessage("弹起:上方向键");
            break;
        case KeyEvent.KEYCODE_DPAD_LEFT:
            ShowMessage("弹起：左方向键");
            break;
        case KeyEvent.KEYCODE_DPAD_RIGHT:
            ShowMessage("弹起:右方向键");
            break;
        }
        return super.onKeyUp(keyCode, event);
    }

   /**按键重复点击事件*/
    public boolean onKeyMultiple(int keyCode, int repeatCount, KeyEvent event)
    {
        return onKeyMultiple(keyCode, repeatCount, event);
    }

    /**触屏事件*/
    public boolean onTouchEvent(MotionEvent event)
    {
        int action = event.getAction();
        if(action ==  MotionEvent.ACTION_CANCEL||action == MotionEvent.ACTION_DOWN||action == MotionEvent.ACTION_MOVE)
        {
            return false;
        }
        //得到触点的位置
        String x = String.valueOf(event.getX());
        String y = String.valueOf(event.getX());

        ShowMessage("触点坐标：(" + x + "," + y +")");
        return super.onTouchEvent(event);
    }

    /**显示触发事件的信息*/
    public void ShowMessage(String str)
    {
        Toast toast = Toast.makeText(this, str, Toast.LENGTH_SHORT);
        toast.show();
    }
}

 

运行结果如下：