package com.lxt008;import com.lxt008.R;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;/** *  * 控件事件通过设置其控件的监听器来监听并处理事件 * 按键按下事件：通过重写onKeyDown方法 * 按键弹起事件：通过重写onKeyUp方法 * 触笔点击事件：通过实现onTouchEvent方法 * 示例中使用了Toast控件： * Toast.makeText(this, string, Toast.LENGTH_SHORT).show(); * 显示提示信息 * */public class Activity01 extends Activity{    public void onCreate(Bundle savedInstanceState)    {        super.onCreate(savedInstanceState);                setContentView(R.layout.main);        //获得Button对象        Button button_ok = (Button) findViewById(R.id.ok);        //设置Button控件监听器        button_ok.setOnClickListener(new Button.OnClickListener() {            public void onClick(View v)            {                //这里处理事件                DisplayToast("点击了OK按钮");            }        });    }    /* 按键按下所触发的事件 */    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");                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:                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");                break;        }                return super.onKeyUp(keyCode, event);    }        public boolean onKeyMultiple(int keyCode, int repeatCount, KeyEvent event)    {                return super.onKeyMultiple(keyCode, repeatCount, event);    }        /* 触笔事件 */    public boolean onTouchEvent(MotionEvent event)    {        int iAction = event.getAction();        if (iAction == MotionEvent.ACTION_CANCEL ||             iAction == MotionEvent.ACTION_DOWN ||             iAction == MotionEvent.ACTION_MOVE)         {            return false;        }        //得到触笔点击的位置        int x = (int) event.getX();        int y = (int) event.getY();                DisplayToast("触笔点击坐标：("+Integer.toString(x)+","+Integer.toString(y)+")");                return super.onTouchEvent(event);    }        /* 显示Toast  */    public void DisplayToast(String str)    {        Toast.makeText(this, str, Toast.LENGTH_SHORT).show();    }}

<?xml version="1.0" encoding="utf-8"?><LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"    android:orientation="vertical"    android:layout_width="fill_parent"    android:layout_height="fill_parent"    >    <TextView      android:layout_width="fill_parent"     android:layout_height="wrap_content"     android:text="@string/hello"    />    <Button    android:id="@+id/ok"    android:layout_width="fill_parent"    android:layout_height="wrap_content"    android:text="OK"/></LinearLayout>