public class MyTask extends AsyncTask<Void, Void, Void> { 
 
    private volatile boolean running = true; 
    private final ProgressDialog progressDialog; 
 
    public MyTask(Context ctx) { 
        progressDialog = gimmeOne(ctx); 
 
        progressDialog.setCancelable(true); 
        progressDialog.setOnCancelListener(new OnCancelListener() { 
            @Override 
            public void onCancel(DialogInterface dialog) { 
                // actually could set running = false; right here, but I'll 
                // stick to contract. 
                cancel(true); 
            } 
        }); 
 
    } 
 
    @Override 
    protected void onPreExecute() { 
        progressDialog.show(); 
    } 
 
    @Override 
    protected void onCancelled() { 
        running = false; 
    } 
 
    @Override 
    protected Void doInBackground(Void... params) { 
 
        while (running) { 
            // does the hard work 
        } 
        return null; 
    } 
 
    // ... 
 
}
这两天要用一个对象的传递始终找不到好的方法，后来在传递bitMap时这个对象时有了点启发
可以讲一个类扩展为implement Serializable interface 
Serializable
//传递: 
   intent.putExtra("MyClass", obj);   
 
// to retrieve object in second Activity 
getIntent().getSerializableExtra("MyClass");