Android开发入门——响应按键按下和弹起事件以及触摸屏事件

只要实现几个方法即可：

boolean onKeyDown（int keyCode,KeyEvent event) ; //按键按下事件

boolean onKeyUp(int keyCode,KeyEvent event) //按键弹起事件

boolean onTouchEvent(MotionEvent event) //触摸屏事件







package exam.apan;


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

public class KeyTestActivity extends Activity 
{
    /** Called when the activity is first created. */
    @Override
    public void onCreate(Bundle savedInstanceState) 
    {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.main);
    }
    
    //按键按下触发的事件   
    public boolean onKeyDown(int keyCode,KeyEvent event)
    {
        switch(keyCode)
        {
            case KeyEvent.KEYCODE_DPAD_CENTER: 
                DisplayToast("按下：中键");
                break;
            case KeyEvent.KEYCODE_DPAD_UP:
                DisplayToast("按下：上方向键");
                break;
            case KeyEvent.KEYCODE_DPAD_DOWN:
                DisplayToast("按下：下方向键");
                break;
            case KeyEvent.KEYCODE_DPAD_LEFT:
                DisplayToast("按下：左方向键");    
                break;
            case KeyEvent.KEYCODE_DPAD_RIGHT:
                DisplayToast("按下：右方向键");

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

               
        }
        return false;
        
    }
   
    
    //笔触事件
    public boolean onTouchEvent(MotionEvent event)
    {
        int iAction = event.getAction();
        if(iAction == MotionEvent.ACTION_CANCEL ||
           iAction == MotionEvent.ACTION_DOWN||
           iAction == MotionEvent.ACTION_MOVE)
        {
            return false;
        }
        
        //得到笔触的位置
        int x = (int)event.getX();
        int y = (int)event.getY();
        DisplayToast("笔触的坐标：(" + x + "," + y + ")");
        
        return false;
    }
    
    //显示Toast
    public void DisplayToast(String string)
    {
        Toast.makeText(KeyTestActivity.this,string,Toast.LENGTH_SHORT).show();
        
    }
}