我如何在android中单击一个按钮就运行一个长代码而不会导致应用崩溃？

Question

I'm using an algo to download a video whenever user place Url on a EditText and hit on a Button. The algo will take some time according to user Connection speed and it will also calculate a value and taking some time in it. Everything works good but whenever I click/press the button twice app crashes so what should i need to do so it will wait until the code execute completely ?

Answer 1

If I'm understanding your question well, you dont want the onClick to be executed twice, right? One way to do this is to create a boolean (false) in the activity attributes, and then, once onClick is executed, change it to "true". For example:

public class MainActivity extends AppCompatActivity {

public boolean clicked = false;

@Override
   protected void onCreate(Bundle savedInstanceState) {
      super.onCreate(savedInstanceState);
      setContentView(R.layout.activity_main);

      final Button button = (Button) findViewById(R.id.button_id);
      button.setOnClickListener(new View.OnClickListener() {
        public void onClick(View v) {
          if(!clicked){
            methodToExecuteYourTask();
            clicked = true;
          }
        }
      });
  }
}

If you need to use the button again to download, once the algo is finished, try to add in the algo a check that changes the value of the boolean to false again. This way, your code inside the if condition will only be executed once.

Answer 2

You should do it in a thread that is not the UI thread. See the following code for an example of such. Read more here .

public void onClick(View v) {
    new Thread(new Runnable() {
        public void run() {
            // Do something in the background
        }
    }).start();
}