安卓模拟系统发送Back键值

public void sendBack(){    
        new Thread(){    
           public void run() {    
                try{    
                 Instrumentation inst = new Instrumentation();    
                 inst.sendKeyDownUpSync(KeyEvent.KEYCODE_BACK);    
                }    
                catch (Exception e) {    
                }    
           }    
        }.start();    
     }  

需要加上权限

<uses-permission android:name="android.permission.INJECT_EVENTS" />

二、这个比较好用

Runtime runtime = Runtime.getRuntime();
runtime.exec("input keyevent " + KeyEvent.KEYCODE_BACK);