executing runOnUiThread on a separate class [duplicate]

Question

Possible Duplicate:
Android how to runOnUiThread in other class?

My Asyn Classes are a separate class file.

public class AdamTask extends AsyncTask<String, Void, String>{
         public void showToast(final String toast)
        {
            runOnUiThread(new Runnable() {
                public void run()
                {
                    Toast.makeText(context, toast, Toast.LENGTH_SHORT).show();
                }
            });
        }
}

How would I execute this method in my AsyncTask Class? I am getting an error The method runOnUiThread(new Runnable(){}) is undefined for the type AdamTask

new AdamTask(Eve.this, How to pass the eve activity here).execute();

Answer 1

Just typecast the context to Activity class

((Activity)context).runOnUiThread(new Runnable()
    {
        public void run()
        { 
             Toast.makeText(context, toast, Toast.LENGTH_SHORT).show();
        }
    });

Answer 2

You need to have the Activity's reference (lets name it activity) and pass it to your AsyncTask class. Then you can call runOnUiThread like this:

activity.runOnUiThread

The runOnUiThread is a method defined in Activity class.

Just add a contsructor to your AsyncTask. Your AsyncTask will look like this:

public class AdamTask extends AsyncTask<String, Void, String> {

private Activity activity; //activity is defined as a global variable in your AsyncTask

public AdamTask(Activity activity) {

    this.activity = activity;
}

public void showToast(final String toast)
    {
        activity.runOnUiThread(new Runnable() {
            public void run()
            {
                Toast.makeText(activity, toast, Toast.LENGTH_SHORT).show();
            }
        });
    }

...

}

Then to call the AsyncTask you need something like this:

AdamTask adamTask = new AdamTask(Eve.this);
adamTask.excecute(yourParams);

UPDATE As Sam mentioned in the comments, AsyncTasks may result in context leaking when configuration changes occur (one example is when screen rotates and the Activity is recreated). A way to deal with this is the headless fragment technique.

Another way, more efficient, is using an event bus. See here for more information (link provided by Sam in the comments).