Question

Here is the code

Variable declared

 public String gpu2dcurent = "1234567";

Asynctask, after finished it should update variable gpu2dcurent, but it doesnt

 private class readgpu2d extends AsyncTask<String, Void, String> {


    protected String doInBackground(String... args) {
         Log.i("MyApp", "Background thread starting");

         String aBuffer = "";

         try {

            File myFile = new File("/sys/devices/platform/kgsl-2d0.0/kgsl/kgsl-2d0/gpuclk");
            FileInputStream fIn = new FileInputStream(myFile);
            BufferedReader myReader = new BufferedReader(
                    new InputStreamReader(fIn));
            String aDataRow = "";
            //String aBuffer = "";
            while ((aDataRow = myReader.readLine()) != null) {
                aBuffer += aDataRow + "\n";
            }

            ;
            myReader.close();

        } catch (Exception e) {
            Toast.makeText(getBaseContext(), e.getMessage(),
                    Toast.LENGTH_SHORT).show();

        }

         return aBuffer.trim();
     }

     protected void onPostExecute(String result) {
         // Pass the result data back to the main activity
        gpu2dcurent = result;
         //Toast.makeText(getBaseContext(), result,
                //Toast.LENGTH_SHORT).show();
         gpu.this.data = result;

         if (gpu.this.pd != null) {
             //gpu.this.pd.dismiss();
         }
     }

    }

Test to see if a variable has a new value. It doesn’t, it displays 1234567

 TextView tx = (TextView)findViewById(R.id.textView3);
tx.setText(gpu2dcurent);

Am i missing something? When i update textView from inside onPostExecute method it works fine but when Asynctask finishes variable value resets to default

 public class gpu extends Activity{

public String gpu2dcurent = "1234567";

Answer 1

I have a doubt you are trying to set text of TextView before completion of your Asynctask.

Yes, either make it, static public String gpu2dcurent = "1234567";

Or, set Text of TextView in onPostExecute()

protected void onPostExecute(String result) {
         // Pass the result data back to the main activity
        gpu2dcurent = result;
         //Toast.makeText(getBaseContext(), result,
                //Toast.LENGTH_SHORT).show();
         gpu.this.data = result;  
         if (gpu.this.pd != null) {
             //gpu.this.pd.dismiss();
         }
      tx.setText(gpu2dcurent);
     }
    }

Update:

After update your code in question,

change this line,

new readgpu2d().execute("blablabla");

to

new readgpu2d().execute("blablabla").get();