XafAsyncActions# XafAsyncActions

This example show the various ways you can call async operations in XAF actions and the behaviour of the UI when doing so.

MyViewController Methods Documentation

ActionWithAsyncModifier_Execute(object sender, SimpleActionExecuteEventArgs e)

Description

Executes two asynchronous tasks sequentially and displays their combined results in a success message.

Problems

• The operations in the task list might take longer to execute than the time the method takes to finish
• In this case the method will finish, the U.I will continue be responsive
• but the tasks will still be running in the background and there is not right way to return to the main thread

ActionWithAsyncModifierAndOsOperations_Execute(object sender, SimpleActionExecuteEventArgs e)

Description

Executes a series of asynchronous tasks and updates the Result property of the TestObject instance. Displays a success message upon completion.

Problems (same as ActionWithAsyncModifier_Execute))

• The operations in the task list might take longer to execute than the time the method takes to finish
• In this case the method will finish, the U.I will continue be responsive
• but the tasks will still be running in the background and there is not right way to return to the main thread

ActionBlockUIThread_Execute(object sender, SimpleActionExecuteEventArgs e)

Executes a series of tasks synchronously, blocking the UI thread. Displays the results in a success message.

Problems

• The U.I will be blocked and so the main thread will be blocked so your application is frozen forever

Task methods to emulate the async operations

Task1()

Asynchronous task that simulates a delay and returns a result string.

Task2()

Asynchronous task that simulates a delay and returns a result string.

GetTaskList()

Returns a list of asynchronous tasks to be executed.

Action with background worker methods

AsyncActionWithAsyncBackgroundWorker_Execute(object sender, SimpleActionExecuteEventArgs e)

Queues a list of tasks to run in the background and sets up progress reporting and completion handling.

ProcessingDone(Dictionary<int, object> results)

Handles the completion of all tasks. Intended to run on the UI thread.

OnReportProgress(int progress, string status, object result)

Reports the progress of task execution to the U.I thread. Displays a status message and logs the result.

Controller methods

OnActivated()

Called when the controller is activated. Can be used to perform various tasks depending on the target view.

OnDeactivated()

Called when the controller is deactivated. Unsubscribes from events and releases resources.

OnViewControlsCreated()

Called when the view controls are created. Can be used to access and customize the target view control.

Utility methods

GetInstance()

Returns the current instance of TestObject from the view.

ViewCommit()

Commits changes to the ObjectSpace if it is modified.

MyViewControllerBlazor Methods Documentation

ActionWithAsyncModifierAndOsOperations_Execute(object sender, SimpleActionExecuteEventArgs e)

Shows a loading indicator while the action is executing. Calls the base method to execute a series of asynchronous tasks.

ActionWithAsyncModifier_Execute(object sender, SimpleActionExecuteEventArgs e)

Shows a loading indicator while the action is executing. Calls the base method to execute two asynchronous tasks sequentially.

AsyncActionWithAsyncBackgroundWorker_Execute(object sender, SimpleActionExecuteEventArgs e)

Shows a loading indicator while the action is executing. Calls the base method to queue a list of tasks to run in the background.

OnReportProgress(int progress, string status, object result)

Reports the progress of task execution to the UI thread. Calls the base method to display a status message and log the result.

ProcessingDone(Dictionary<int, object> results)

Handles the completion of all tasks. Calls the base method to run on the UI thread and hides the loading indicator.