Command

Namespace: Wisej.Web

Assembly: Wisej.Framework (3.5.0.0)

Implements the ICommand interface wrapping execute and canExecute actions.

C#

public class Command : ICommand

VB.NET

Public Class Command
    Inherits ICommand

You can use this class and Command to wrap custom commands to bind to controls that implement the ICommandSource interface. A view model class can expose as many commands as you like. You can bind (or assign) a command to the Command property (see Command for example).

public CommandDemoViewModel : INotifyPropertyChanged
{
  public event PropertyChangedEventHandler PropertyChanged;
  
  public int Number { ... }
  
  public Wisej.Web.ICommand AddCommand { get; }
  
  public CommandDemoViewModel()
  {
    this.AddCommand = new Command(args => this.Number++);
    
    // Or
    this.AddCommand = new Command(
      execute: args => this.Number++,
      canExecute: args => this.Number < 10
    );
  }
}

Now you can use data binding or a code assignment to connect the view model's Add command to a button's Command property.

Constructors

Command(execute, canExecute)

Initializes a new Command wrapping am execute method and an canExecute method.

Name	Type	Description
execute	Action	Invoked by the ICommandSource to perform a command.
canExecute	Func<Boolean>	Invoked by the ICommandSource to determine whether it can execute the execute function.

Command(execute, canExecute)

Initializes a new Command wrapping am execute method and an canExecute method.

Name	Type	Description
execute	Action<CommandArgs>	Invoked by the ICommandSource to perform a command.
canExecute	Func<CommandArgs, Boolean>	Invoked by the ICommandSource to determine whether it can execute the execute function.

Methods

CanExecute(args)

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

Parameter	Type	Description
args	CommandArgs	A CommandArgs that contains data that can be used by the command.

Returns: Boolean. true if this command can be executed; otherwise, false.

Execute(args)

Executes the command method.

Parameter	Type	Description
args	CommandArgs	A CommandArgs that contains data that can be used by the command.

RaiseCanExecuteChanged()

Fires the CanExecuteChanged event.

Events

CanExecuteChanged

EventHandler Fired when the result of the CanExecute method changes.

Inherited By

Name	Description
Command<T>	Implements the ICommand interface wrapping execute and canExecute actions.

Implements

Name	Description
ICommand	Defines a command that can be used for data binding.