Class AsyncRelayCommand

A command that mirrors the functionality of RelayCommand, with the addition of accepting a Func<TResult> returning a Task as the execute action, and providing an executionTask property that notifies changes when ExecuteAsync(Object) is invoked and when the returned Task completes.

Inheritance

Object

AsyncRelayCommand

Inherited Members

Object.ToString()

Object.Equals(Object)

Object.Equals(Object, Object)

Object.ReferenceEquals(Object, Object)

Object.GetHashCode()

Object.GetType()

Object.MemberwiseClone()

Namespace: Unity.AppUI.MVVM

Syntax

public class AsyncRelayCommand : IAsyncRelayCommand, IRelayCommand, ICommand, INotifyPropertyChanged

Constructors

AsyncRelayCommand(Func<CancellationToken, Task>)

Initializes a new instance of the AsyncRelayCommand class.

Declaration

public AsyncRelayCommand(Func<CancellationToken, Task> cancellableExecute)

Parameters

Type	Name	Description
Func<CancellationToken, Task>	cancellableExecute	The Func<TResult> to invoke when ExecuteAsync(Object) is called.

Exceptions

Type	Condition
ArgumentNullException	If the execute argument is null.

AsyncRelayCommand(Func<CancellationToken, Task>, Func<Boolean>)

Initializes a new instance of the AsyncRelayCommand class.

Declaration

public AsyncRelayCommand(Func<CancellationToken, Task> cancellableExecute, Func<bool> canExecute)

Parameters

Type	Name	Description
Func<CancellationToken, Task>	cancellableExecute	The Func<TResult> to invoke when ExecuteAsync(Object) is called.
Func<Boolean>	canExecute	The Func<TResult> to invoke when CanExecute() is called.

Exceptions

Type	Condition
ArgumentNullException	If the execute argument is null.

AsyncRelayCommand(Func<CancellationToken, Task>, Func<Boolean>, AsyncRelayCommandOptions)

Initializes a new instance of the AsyncRelayCommand class.

Declaration

public AsyncRelayCommand(Func<CancellationToken, Task> cancellableExecute, Func<bool> canExecute, AsyncRelayCommandOptions options)

Parameters

Type	Name	Description
Func<CancellationToken, Task>	cancellableExecute	The Func<TResult> to invoke when ExecuteAsync(Object) is called.
Func<Boolean>	canExecute	The Func<TResult> to invoke when CanExecute() is called.
AsyncRelayCommandOptions	options	The AsyncRelayCommandOptions to use.

Exceptions

Type	Condition
ArgumentNullException	If the execute argument is null.

AsyncRelayCommand(Func<CancellationToken, Task>, AsyncRelayCommandOptions)

Initializes a new instance of the AsyncRelayCommand class.

Declaration

public AsyncRelayCommand(Func<CancellationToken, Task> cancellableExecute, AsyncRelayCommandOptions options)

Parameters

Type	Name	Description
Func<CancellationToken, Task>	cancellableExecute	The Func<TResult> to invoke when ExecuteAsync(Object) is called.
AsyncRelayCommandOptions	options	The AsyncRelayCommandOptions to use.

Exceptions

Type	Condition
ArgumentNullException	If the execute argument is null.

AsyncRelayCommand(Func<Task>)

Initializes a new instance of the AsyncRelayCommand class.

Declaration

public AsyncRelayCommand(Func<Task> execute)

Parameters

Type	Name	Description
Func<Task>	execute	The Func<TResult> to invoke when ExecuteAsync(Object) is called.

Exceptions

Type	Condition
ArgumentNullException	If the execute argument is null.

AsyncRelayCommand(Func<Task>, Func<Boolean>)

Initializes a new instance of the AsyncRelayCommand class.

Declaration

public AsyncRelayCommand(Func<Task> execute, Func<bool> canExecute)

Parameters

Type	Name	Description
Func<Task>	execute	The Func<TResult> to invoke when ExecuteAsync(Object) is called.
Func<Boolean>	canExecute	The Func<TResult> to invoke when CanExecute() is called.

Exceptions

Type	Condition
ArgumentNullException	If the execute argument is null.

AsyncRelayCommand(Func<Task>, Func<Boolean>, AsyncRelayCommandOptions)

Initializes a new instance of the AsyncRelayCommand class.

Declaration

public AsyncRelayCommand(Func<Task> execute, Func<bool> canExecute, AsyncRelayCommandOptions options)

Parameters

Type	Name	Description
Func<Task>	execute	The Func<TResult> to invoke when ExecuteAsync(Object) is called.
Func<Boolean>	canExecute	The Func<TResult> to invoke when CanExecute() is called.
AsyncRelayCommandOptions	options	The AsyncRelayCommandOptions to use.

Exceptions

Type	Condition
ArgumentNullException	If the execute argument is null.

AsyncRelayCommand(Func<Task>, AsyncRelayCommandOptions)

Initializes a new instance of the AsyncRelayCommand class.

Declaration

public AsyncRelayCommand(Func<Task> execute, AsyncRelayCommandOptions options)

Parameters

Type	Name	Description
Func<Task>	execute	The Func<TResult> to invoke when ExecuteAsync(Object) is called.
AsyncRelayCommandOptions	options	The AsyncRelayCommandOptions to use.

Exceptions

Type	Condition
ArgumentNullException	If the execute argument is null.

Fields

CanBeCanceledChangedEventArgs

The arguments for the PropertyChanged event raised by the canBeCancelled property.

Declaration

public static readonly PropertyChangedEventArgs CanBeCanceledChangedEventArgs

Field Value

Type	Description
PropertyChangedEventArgs

ExecutionTaskChangedEventArgs

The arguments for the PropertyChanged event raised by the executionTask property.

Declaration

public static readonly PropertyChangedEventArgs ExecutionTaskChangedEventArgs

Field Value

Type	Description
PropertyChangedEventArgs

IsCancellationRequestedChangedEventArgs

The arguments for the PropertyChanged event raised by the isCancellationRequested property.

Declaration

public static readonly PropertyChangedEventArgs IsCancellationRequestedChangedEventArgs

Field Value

Type	Description
PropertyChangedEventArgs

IsRunningChangedEventArgs

The arguments for the PropertyChanged event raised by the isRunning property.

Declaration

public static readonly PropertyChangedEventArgs IsRunningChangedEventArgs

Field Value

Type	Description
PropertyChangedEventArgs

Properties

canBeCancelled

Gets the CancellationTokenSource that can be used to cancel the asynchronous operation.

Declaration

public bool canBeCancelled { get; }

Property Value

Type	Description
Boolean

Implements

IAsyncRelayCommand.canBeCancelled

executionTask

Gets the Task that represents the asynchronous operation.

Declaration

public Task executionTask { get; set; }

Property Value

Type	Description
Task

Implements

IAsyncRelayCommand.executionTask

isCancellationRequested

Gets the CancellationTokenSource that can be used to cancel the asynchronous operation.

Declaration

public bool isCancellationRequested { get; }

Property Value

Type	Description
Boolean

Implements

IAsyncRelayCommand.isCancellationRequested

isRunning

Gets the CancellationTokenSource that can be used to cancel the asynchronous operation.

Declaration

public bool isRunning { get; }

Property Value

Type	Description
Boolean

Implements

IAsyncRelayCommand.isRunning

Methods

Cancel()

Cancels the AsyncRelayCommand on the current command target.

Declaration

public void Cancel()

Implements

IAsyncRelayCommand.Cancel()

CanExecute()

Determines whether this AsyncRelayCommand can execute in its current state.

Declaration

public bool CanExecute()

Returns

Type	Description
Boolean	true if this AsyncRelayCommand can execute; otherwise, false.

CanExecute(Object)

Determines whether this AsyncRelayCommand can execute in its current state.

Declaration

public bool CanExecute(object parameter)

Parameters

Type	Name	Description
Object	parameter	The parameter to use when determining whether this AsyncRelayCommand can execute.

Returns

Type	Description
Boolean	true if this AsyncRelayCommand can execute; otherwise, false.

Implements

ICommand.CanExecute(Object)

Execute()

Executes the AsyncRelayCommand on the current command target.

Declaration

public void Execute()

Execute(Object)

Executes the AsyncRelayCommand on the current command target.

Declaration

public void Execute(object parameter)

Parameters

Type	Name	Description
Object	parameter	The parameter to use when executing the AsyncRelayCommand.

Implements

ICommand.Execute(Object)

ExecuteAsync(Object)

Executes the AsyncRelayCommand on the current command target.

Declaration

public Task ExecuteAsync(object parameter)

Parameters

Type	Name	Description
Object	parameter	The parameter to use when executing the AsyncRelayCommand.

Returns

Type	Description
Task	The Task that represents the asynchronous operation.

Implements

IAsyncRelayCommand.ExecuteAsync(Object)

NotifyCanExecuteChanged()

Raises the CanExecuteChanged event.

Declaration

public void NotifyCanExecuteChanged()

Implements

IRelayCommand.NotifyCanExecuteChanged()

Events

CanExecuteChanged

Event that is raised when changes occur that affect whether or not the AsyncRelayCommand should execute.

Declaration

public event EventHandler CanExecuteChanged

Event Type

Type	Description
EventHandler

Implements

ICommand.CanExecuteChanged

PropertyChanged

Event that is raised when the executionTask property changes.

Declaration

public event PropertyChangedEventHandler PropertyChanged

Event Type

Type	Description
PropertyChangedEventHandler

Implements

INotifyPropertyChanged.PropertyChanged