CODEWITHSUNDEEP
androidmultithreadinguser-interfaceui-thread
Vinod Maurya
Vinod Maurya

Reputation: 4187

Handling UI from other thread

I have a class which extends the Runnable. This class performs some heavy operation (basically downloads the image from network) in different thread. I want to update the UI (display the downloaded image to an ImageView) from this class. I have tried using handler but did not succeed. Here is my code:

class DataReceiver implements Runnable
{
    public Bitmap bmp;
    Public Handler uiHandle;
    @Override
    public void run()
    {
        while(true)
        {
            //do image download process here
        }
    }
}

In main activity

ImageView img = (ImageView)findViewById(R.id.dispImg);
DataReceiver dr=new DataReceiver();

Handler uiHandler = new Handler()
{
    @Override
    public void handleMessage(Message msg)
    {
        updateUI();
    }
}

dr.uiHandle = uiHandler;
(new Thread(dr)).start();

public void updateUI()
{
    img.setBitmap(dr.bmp);
}

Is it the correct method for updating UI?

Upvotes: 3

Views: 2059

Answers (3)

Egor
Egor

Reputation: 40218

To update the UI from another thread use

activity.runOnUIThread(new Runnable());

Upvotes: 0

Ben Williams
Ben Williams

Reputation: 6167

You could use AsyncTask instead, do what you're currently doing in run() in doInBackground, and then do the UI update in the task's onPostExecute.

Upvotes: 4

PedroAGSantos
PedroAGSantos

Reputation: 2346

almost ;D you need on the class thread add the that linebefore while do:

while(true)
    {
      //do image download process here
    }
uiHandle.sendEmptyMessage(0);

Upvotes: 2

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