Class AsyncDelegateCommand

The AsyncDelegateCommand allows use the System.Windows.Input.ICommand interface with asynchronous functionality. While the underlying asynchronous functionality is running System.Windows.Input.ICommand.CanExecute(System.Object) always returns false and System.Windows.Input.ICommand.CanExecuteChanged is automatically called when execution starts and ends.

potential exceptions occurring during execution are automatically dispatched into the UI thread.

Inheritance

System.Object

AsyncDelegateCommandBase

AsyncDelegateCommand

Implements

IAsyncDelegateCommand

System.Windows.Input.ICommand

Inherited Members

AsyncDelegateCommandBase.IsExecuting

AsyncDelegateCommandBase.CanExecuteChanged

AsyncDelegateCommandBase.RaiseCanExecuteChanged()

System.Object.Equals(System.Object)

System.Object.Equals(System.Object, System.Object)

System.Object.GetHashCode()

System.Object.GetType()

System.Object.MemberwiseClone()

System.Object.ReferenceEquals(System.Object, System.Object)

System.Object.ToString()

Namespace: Sartorius.SAF.Presentation.Commands

Assembly: Sartorius.SAF.Presentation.dll

Syntax

public sealed class AsyncDelegateCommand : AsyncDelegateCommandBase, IAsyncDelegateCommand, ICommand

Examples

The following example shows how to use the AsyncDelegateCommand.

    [Export]
public class AddViewModel
{
    private readonly AsyncDelegateCommand addCommand;
    private readonly IItemService service;

    [ImportingConstructor]
    public AddViewModel(IItemService service)
    {
        this.service = service;
        this.addCommand = new AsyncDelegateCommand(OnAdd);
    }

    public ICommand AddCommand => this.addCommand;

    private async Task OnAdd()
    {
        using (new BusyIndicator())
        {
            await this.service.AddAsync(new Item())
                      .ConfigureAwait(true);
        } // disposal of BusyIndicator is done in UI thread
    }
}

Constructors

AsyncDelegateCommand(Func<Task>)

Creates a new instance of the AsyncDelegateCommand class with the specified async execution function.

Declaration

public AsyncDelegateCommand(Func<Task> executeFunc)

Parameters

Type	Name	Description
System.Func<System.Threading.Tasks.Task>	executeFunc	The asynchronous function that this command should execute.

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

Creates a new instance of the AsyncDelegateCommand class with the specified async execution function and can execute function.

Declaration

public AsyncDelegateCommand(Func<Task> executeFunc, Func<bool> canExecute)

Parameters

Type	Name	Description
System.Func<System.Threading.Tasks.Task>	executeFunc	The asynchronous function that this command should execute.
System.Func<System.Boolean>	canExecute	The function that verifies whether the command can execute in its current state.

Methods

CanExecute()

Defines the method that determines whether the command can execute in its current state.

Declaration

public bool CanExecute()

Returns

Type	Description
System.Boolean	true, if this command can be executed; otherwise, false.

ExecuteAsync()

Defines the method to be called when the command is invoked.

Declaration

public async Task ExecuteAsync()

Returns

Type	Description
System.Threading.Tasks.Task	The task object representing the asynchronous operation.

Explicit Interface Implementations

ICommand.CanExecute(Object)

Declaration

bool ICommand.CanExecute(object parameter)

Parameters

Type	Name	Description
System.Object	parameter

Returns

Type	Description
System.Boolean

ICommand.Execute(Object)

Declaration

void ICommand.Execute(object parameter)

Parameters

Type	Name	Description
System.Object	parameter

Implements

IAsyncDelegateCommand

System.Windows.Input.ICommand

Extension Methods

CollectionExtensions.AddRange<T, TCollection>(TCollection, IEnumerable<T>)

SerializableObjectCloneExtension.Clone<T>(T)

See Also

IAsyncDelegateCommand