Summary of code snippets for Android implementation of Back function

The methods to implement Back key functions are:

One: Rewrite the onBackPressed method

Copy the codeThe code is as follows:

@Override

 public void onBackPressed() {

  // do something what you want

  ();

 }

2: Use the test framework Instrumentation to simulate the action of pressing any key. Note that this method cannot be used in the main thread and can only open a new thread. The problem is that the reaction speed is slow and it is not recommended to use it in the project.
Call the onBack() method; generate a back key click effect

public void onBack(){
 new Thread(){
  public void run() {
  try{
   Instrumentation inst = new Instrumentation();
   (KeyEvent.KEYCODE_BACK);
  }
  catch (Exception e) {
         ("Exception when onBack", ());
       }
  }
 }.start();

 }

3: This method is collected on the Internet and has no code verification.

try{
  Runtime runtime=();
  ("input keyevent " + KeyEvent.KEYCODE_BACK);
 }catch(IOException e){
  ("Exception when doBack", ());
 }

Four: Rewrite dispatchKeyEvent

@Override
	public boolean dispatchKeyEvent(KeyEvent event) {
		// TODO Auto-generated method stub
		if (() == KeyEvent.ACTION_DOWN
				&amp;&amp; () == KeyEvent.KEYCODE_BACK) {
			//do something what you want
			return true;//Return true, consume the event, and will not continue to call onBackPressed		}
		return (event);
	}

5: This method is not a complete function of the Back key. This method can only turn off the current Activity, which means it is effective for an application with only a single Activity. If it is powerless for an application with more than one Activity, it will be powerless.

Copy the codeThe code is as follows:

public void exitProgrames(){

(());

}

Use this method to append permissions: <uses-permission android:name=".RESTART_PACKAGES" />