模拟按键操作的几种方式

import android.app.Activity;
import android.app.Instrumentation;
import android.os.Bundle;
import android.view.KeyEvent;

public class MainActivity extends Activity {

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);
        // sendKeyCode1(KeyEvent.KEYCODE_MEDIA_STOP);
        sendKeyCode2(KeyEvent.KEYCODE_VOLUME_DOWN);
    }

    /**
     * 用Runtime模拟按键操作
     * 
     * @param keyCode
     *            按键事件(KeyEvent)的按键值
     */
    private void sendKeyCode1(int keyCode) {
        try {
            // 按键操作命令 11.24勘误，之前错误的写成了"input keycode"
            String keyCommand = "input keycode " + keyCode;
            // 调用Runtime模拟按键操作
            Runtime.getRuntime().exec(keyCommand);
        } catch (Exception e) {
            e.printStackTrace();
        }
    }

    /**
     * 
     * 使用Instrumentation接口：对于非自行编译的安卓系统，无法获取系统签名，只能在前台模拟按键，不能后台模拟
     * 注意:调用Instrumentation的sendKeyDownUpSync方法必须另起一个线程，否则无效
     * @param keyCode
     *            按键事件(KeyEvent)的按键值
     * 
     */
    private void sendKeyCode2(final int keyCode) {
        new Thread(new Runnable() {
            @Override
            public void run() {
                try {
                    // 创建一个Instrumentation对象
                    Instrumentation inst = new Instrumentation();
                    // 调用inst对象的按键模拟方法
                    inst.sendKeyDownUpSync(keyCode);
                } catch (Exception e) {
                    e.printStackTrace();
                }
            }
        }).start();
    }
    
    /**
     * 
     * 此方法使用反射调用系统IWindowManager隐藏API：兼容性较差，稳定性不好，容易出错。另外实际编译时发生错误，原因暂时不明。
     * 暂时还未掌握Java的反射机制，留待以后测试
     * @param keyCode
     * 
     */
    private void sendKeyCode3(int keyCode) {
        /*此方法中那个的IWindowManager是不存在的，需要使用Java的反射机制才能实现*/
        /**
        final int keyCode = key;
        Thread sendKeyDelay = new Thread(){
            public void run() {
                try {
                    Thread.sleep(100);
                    
                    long now = SystemClock.uptimeMillis();
                    KeyEvent keyDown = new KeyEvent(now, now, KeyEvent.ACTION_DOWN,
                            keyCode, 0);
                    IWindowManager wm = IWindowManager.Stub.asInterface(
                            ServiceManager.getService("window"));
                    wm.injectKeyEvent(keyDown, false);
                    
                    KeyEvent keyUp = new KeyEvent(now, now, KeyEvent.ACTION_UP,
                            keyCode, 0);
                    wm.injectKeyEvent(keyUp, false);
                } catch (InterruptedException e) {
                    e.printStackTrace();
                } catch (RemoteException e) {
                    e.printStackTrace();
                }
            }
        };
        sendKeyDelay.start();
         */
    }

}