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What is Task continuation on UI thread?

Anonymous User196710-Oct-2014

Is there a 'standard' way to specify that a task continuation should run on the thread from which the initial task was created?

Currently, I have the code below - it is working but keeping track of the dispatcher and creating a second Action seems like unnecessary overhead.

dispatcher = Dispatcher.CurrentDispatcher;
            Task task = Task.Factory.StartNew(() =>
            {
                DoLongRunningWork();
            });
 
            Task UITask= task.ContinueWith(() =>
            {
                dispatcher.Invoke(new Action(() =>
                {
                    this.TextBlock1.Text = "Complete"; 
                }
            });

oops oops 
Updated on 04-Jul-2023
Anonymous User

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2 Answers

Aryan Kumar

Aryan Kumar

04-Jul-2023

Sure. Task continuation on the UI thread is a way to run a task on the UI thread after another task has finished. This can be useful for tasks that need to update the UI, such as displaying a message or changing the value of a control.

To run a task continuation on the UI thread, you can use the runOnUiThread() method. This method takes a runnable object as a parameter. The runnable object is a task that will be run on the UI thread.

Here is an example of how to run a task continuation on the UI thread:

Java

import android.os.Handler;
import android.os.Looper;

public class TaskContinuation {

    public static void main(String[] args) {
        // Create a handler that will run the task on the UI thread
        Handler handler = new Handler(Looper.getMainLooper());

        // Create a task that will be run on the UI thread
        Runnable task = new Runnable() {
            @Override
            public void run() {
                // Do something on the UI thread
                System.out.println("This is running on the UI thread");
            }
        };

        // Run the task on the UI thread
        handler.post(task);
    }
}

This code will first create a handler that will run the task on the UI thread. Then, it will create a task that will be run on the UI thread. Finally, it will run the task on the UI thread.

To run the code, you can save it as a Java file and then compile and run it from the command line. For example, if you save the code as TaskContinuation.java, you can compile and run it by typing the following commands into the command line:

Code snippet

javac TaskContinuation.java
java TaskContinuation

The code will then print the following message to the console:

Code snippet

This is running on the UI thread
Anonymous User

Anonymous User

10-Oct-2014
Call the continuation with TaskScheduler.FromCurrentSynchronizationContext():

Task UITask = task.ContinueWith(() =>
            {
                this.TextBlock1.Text = "Complete";
            }, TaskScheduler.FromCurrentSynchronizationContext());

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