Question

I would like to know how to create a TextView inside of a thread:

Thread t = new thread() {
  public void run() {
    for(int i = 0; i < 63; i++) {
      TextView tv = new TextView();
      tv.setText("What to do");
    }
  }
}
t.start();

What I don’t understand what to do is what is suppose to be inside the construct method for TextView?

Answer 1

1. To answer your question: to create a TextView you must supply it with a Context. Activity and Application both extend Context and are most often used where a Context is necessary. In your case you should use the Activity whcih the created TextView will be shown in. So, to modify your code:

   class MyActivity extends Activity {
     public void someMethod() {
       Thread t = new Thread() {
         @override public void run() {
           for(int i = 0; i < 63; i++) {
             TextView tv = new TextView(MyActivity.this);
             tv.setText("What to do");
           }
         }
       };
       t.start();
     }
   }
   

2. This is important, even though you didn’t ask about it: a TextView is a UI control. It is only legal to create a UI control on the UI thread. Creating it in a different thread may lead to all kinds of trouble. One way of doing this from a different thread is to use Activity.runOnUiThread() method:

   class MyActivity extends Activity {
     public void someMethod() {
       Thread t = new Thread() {
         @override public void run() {
           for(int i = 0; i < 63; i++) {
             runOnUiThread(new Runnable() {
               void run() {
                 TextView tv = new TextView(MyActivity.this);
                 tv.setText("What to do");
               }
             });
           }
         }
       };
       t.start();
     }
   }
   

Disclaimer: Even though I fixed some mistakes in the code above, I didn’t test it. There can still be errors.