How to change the text of edittext form a thread in another class than where the edittext is declared?

Question

I have two classes: a and b. In class ai have thread that increments the variable x by one while it's value is smaller than 1000. In class b(Activity class), i have a EditText named ed. Everytime x increments by one in class a, i want to set the text of ed from class b to x. How can this be done? See code below.

public  Class a
    {
         int x = 0;
         private void startThread()
         {
           MyThread = new Thread(new Runnable() 
           {
             public void run() 
             {
              while(x<1000)
              {
               x++;
               //Change the text of ed from class b to x!!!!
               sleep(100);
              }
             }

           });
           MyThread.start();

         }

    }





Class b extends Activity{
 EditText ed;

@Override
    public void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.main);
        ed =(EditText)findViewById(....);
    }


}

Answer 1

IMO，您应该使用Observer模式 ，其中A类是Observer ， B类是Subject

Answer 2

I don't know your application, but I have 2 suggestions:

• Class A (class names always start with a capital letter), should keep a reference to class B , eg private final B reference

• There should be anoter class that provides a reference to class B .

EDIT

As suggested in the comment, you should use MVC . It solves your problem by nature.

Answer 3

public  Class a
{
     int x = 0;
     private void startThread()
     {
       MyThread = new Thread(new Runnable() 
       {
         public void run() 
         {
          while(x<1000)
          {
           x++;
           b.notifyEdittext(x);
           sleep(100);
          }
         }

       });
       MyThread.start();

     }

}

Class b extends Activity{
EditText ed;

@Override
public void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.main);
    ed =(EditText)findViewById(....);
}

public static void notifyEdittext(int counter){
 if(ed!=null){
   ed.setText(ed.getText()+counter);
 }
}
}