Interface IAsyncRelayCommand

An interface expanding IRelayCommand to support asynchronous operations.

Inherited Members

IRelayCommand.NotifyCanExecuteChanged()

ICommand.CanExecute(object)

ICommand.Execute(object)

ICommand.CanExecuteChanged

INotifyPropertyChanged.PropertyChanged

Namespace: Unity.AppUI.MVVM

Assembly: Unity.AppUI.MVVM.dll

Syntax

public interface IAsyncRelayCommand : IRelayCommand, ICommand, INotifyPropertyChanged

Properties

canBeCancelled

Gets a value indicating whether a running operation for this command can currently be canceled.

Declaration

bool canBeCancelled { get; }

Property Value

Type	Description
bool

Remarks

The exact sequence of events that types implementing this interface should raise is as follows:

• The command is initially not running: isRunning, canBeCancelled and isCancellationRequested are false.
  
• The command starts running: isRunning and canBeCancelled switch to true. isCancellationRequested is set to false.
  
• If the operation is canceled: canBeCancelled switches to false and isCancellationRequested switches to true.
  
• The operation completes: isRunning and canBeCancelled switch to false. The state of isCancellationRequested is undefined.
  This only applies if the underlying logic for the command actually supports cancellation. If that is not the case, then canBeCancelled and isCancellationRequested will always remain false regardless of the current state of the command.

executionTask

Gets the last scheduled Task, if available. This property notifies a change when the Task completes.

Declaration

Task? executionTask { get; }

Property Value

Type	Description
Task

isCancellationRequested

Gets a value indicating whether a running operation for this command has been cancelled.

Declaration

bool isCancellationRequested { get; }

Property Value

Type	Description
bool

isRunning

Gets a value indicating whether an operation for this command is currently running.

Declaration

bool isRunning { get; }

Property Value

Type	Description
bool

Methods

Cancel()

Attempts to cancel the currently running operation for this command.

Declaration

void Cancel()

ExecuteAsync(object?)

Executes the command asynchronously.

Declaration

Task ExecuteAsync(object? parameter)

Parameters

Type	Name	Description
object	parameter	The input parameter.

Returns

Type	Description
Task	A Task representing the asynchronous operation.