How to cancel AsyncTask

I found great solution to solve the AsyncTask cancel problem

found this so annoying to solve but it fixed the cancelation problem of AsyncTask of mine so sharing with you guys

when i was using Android emulator and running Oreo version on it and trying 

asyncTaskObj.cancle(true);

it was perfectly working i.e it was perfectly calling onCancelled() method of AsyncTask

but problem arise when i tried to run it in my Marshmallow version android device, it was not calling onCancelled() method of AsyncTask so i found a solution where we call asyncTaskObj.cancle(true); i.e. in onClick event we can do version check and if version is smaller then Oreo then manually call onCancelled() method and also check if isCancelled() is true i.e. Eg:

mButtonCancel.setOnClickListener(new View.OnClickListener() {
    @Override

    public void onClick(View view) {
        //set state of cancel for AsyncTask        

        myAsyncTask.cancel(true);
        //checking if version is samller then Oreo        

        if (myAsyncTask.isCancelled() && Build.VERSION.SDK_INT < Build.VERSION_CODES.O)
            myAsyncTask.onCancelled();
    }
});

and then in onCancelled() method of AsyncTask we can do 

if (isCancelled()){

}

Eg: 

@Overrideprotected void onCancelled() {
    super.onCancelled();
    if (isCancelled()) {

        //write all your after cancellation code here

        InputMsg.showToastShort(mContext, "Downloading canceled! Status: " + isCancelled());
        InputMsg.showLog("isCancelled(): " + isCancelled());
    }
}

in this was onCancelled() method also will not be called two times in Oreo version of  android and onCancelled() will be called once in all version of android for per object of AsyncTask

Eg code:

public class MainActivity extends AppCompatActivity {

    ProgressBar mProgressBar;
    Button mButtonStart, mButtonCancel;
    MyAsyncTask myAsyncTask;
    Context mContext = MainActivity.this;
    @Override

    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);
        mProgressBar = (ProgressBar) findViewById(R.id.progressBar);
        mButtonStart = (Button) findViewById(R.id.buttonStart);
        mButtonCancel = (Button) findViewById(R.id.buttonCancel);
        mProgressBar.setMax(100);
        mProgressBar.setVisibility(View.INVISIBLE);
        mButtonCancel.setEnabled(false);
        mButtonStart.setOnClickListener(new View.OnClickListener() {
            @Override

            public void onClick(View view) {
                myAsyncTask = new MyAsyncTask();
                mButtonCancel.setEnabled(true);
                myAsyncTask.execute();
            }
        });
        mButtonCancel.setOnClickListener(new View.OnClickListener() {
            @Override

            public void onClick(View view) {
                //set state of cancel for AsyncTask                

                myAsyncTask.cancel(true);
                //checking if version is samller then Oreo                

                if (myAsyncTask.isCancelled() && Build.VERSION.SDK_INT < Build.VERSION_CODES.O)
                    myAsyncTask.onCancelled();
            }
        });
    }

    private class MyAsyncTask extends AsyncTask<Void, Integer, Boolean> {
        @Override

        protected void onPreExecute() {
            super.onPreExecute();
            mProgressBar.setVisibility(View.VISIBLE);
        }
        @Override

        protected Boolean doInBackground(Void... voids) {
            for (int i = 1; i <= 100; i++) {
                publishProgress(i);
                try {
                    Thread.sleep(50);
                } catch (InterruptedException e) {
                    InputMsg.showLog(e.getMessage());
                }
            }
            return true;
        }
        @Override

        protected void onProgressUpdate(Integer... values) {
            mProgressBar.setProgress(values[0]);
            if (values[0] == 1) {
                mButtonStart.setEnabled(false);
                mButtonCancel.setEnabled(true);
            } else if (values[0] == 100) {
                mButtonStart.setEnabled(true);
                mButtonCancel.setEnabled(false);
            }
        }
        @Override

        protected void onPostExecute(Boolean aBoolean) {
            InputMsg.showToastLong(mContext, "Status: " + aBoolean);
            mProgressBar.setVisibility(View.INVISIBLE);
        }
        @Override

        protected void onCancelled() {
            super.onCancelled();
            if (isCancelled()) {
                mProgressBar.setProgress(0);
                mProgressBar.setVisibility(View.INVISIBLE);
                mButtonStart.setEnabled(true);
                mButtonCancel.setEnabled(false);
                InputMsg.showToastShort(mContext, "Downloading canceled! Status: " + isCancelled());
                InputMsg.showLog("isCancelled(): " + isCancelled());
            }
        }
    }

}

This worked for me so shared this post

hope this helps :)