Android – 按下后退按钮后停止AsyncTask并返回上一个Activity

我有一个AsyncTask,我希望它按下后退按钮时执行.我还希望应用程序返回到之前显示的Activity.似乎我已经设法停止任务但应用程序没有返回到上一个活动.有任何想法吗？这是我的代码摘录

private class MyTask extends AsyncTask<Void,Void,Void> implements OndismissListener{
    private boolean exception= false;

    @Override
    protected void onPreExecute(){
        pd = ProgressDialog.show(
                IscrizioniActivity.this,"Please wait...","Loading the data",true,new DialogInterface.OnCancelListener(){
                    public void onCancel(DialogInterface dialog) {
                        MyTask.this.cancel(true);
                    }
                }
        );
    }

    @Override
    protected Void doInBackground(Void... voids) {
        //do something
        return (null);
    }

    @Override
    protected void onPostExecute(Void voids) {
        pd.dismiss();
        //do something

    }

    public void ondismiss(DialogInterface dialog) {

        this.cancel(true);
    }

}

问候.

解决方法

pd.setCancelable(true);
    pd.setonCancelListener(cancelListener);
    bCancelled=false;

 pd is your progressdialog Box

现在使用cancelListner

OnCancelListener cancelListener=new OnCancelListener(){
    @Override
    public void onCancel(DialogInterface arg0){
        bCancelled=true;
        finish();
    }
};