Question

Here is the code inside main Activity class, which works fine..

public void onStart() {
    super.onStart();

mHandler = new Handler();
    context = this;
    ...
}

And the following code gives problem, don’t know why:

public void onStart() {
    super.onStart();

    new Thread(new Runnable(){
            public void run(){
            mHandler = new Handler();
            context = this;
            ...
        }
    }).start();
}

Answer 1

new Thread(new Runnable(){
            public void run(){
            mHandler = new Handler();
            context = this;
            ...
        }
    }).start();

In above code .this refers to Thread (Runnable) class object not a Current Activity. And you can not cast Thread (Runnable) object to Android Context.

or something like,

context = <MainActivity>.this