android 按键注入，模拟back,home,menu按键

第一，要有 < uses-permission android:name = "android.permission.INJECT_EVENTS"/>    

第二，需要这个 android:sharedUserId = "android.uid.system"  系统app 

第三，cmd ="input keyevent 4" //back键注入

public String doExec(String cmd) { 

             String s = "/n"; 

             try { 

                 Process p = Runtime. getRuntime().exec(cmd); 

                 BufferedReader in = new BufferedReader( 

                                     new InputStreamReader(p.getInputStream())); 

                 String line = null; 

                 while ((line = in.readLine()) != null) { 

                     s += line + "/n";                

                 } 

             } catch (IOException e) { 

                 // TODO Auto-generated catch block 

                 e.printStackTrace(); 

             } 

             Log. d("voice" , "s = " + s);

             return cmd;      

         }

第四，需要系统签名