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// Original author - Josh Smith - http://msdn.microsoft.com/en-us/magazine/dd419663.aspx#id0090030
using System;
using System.Diagnostics;
using System.Windows.Input;
namespace MicroMvvm
{
/// <summary>
/// A command whose sole purpose is to relay its functionality to other objects by invoking delegates. The default return value for the CanExecute method is 'true'.
/// </summary>
public class RelayCommand<T> : ICommand
{
#region Declarations
readonly Predicate<T> _canExecute;
readonly Action<T> _execute;
#endregion
#region Constructors
/// <summary>
/// Initializes a new instance of the <see cref="RelayCommand<T>"/> class and the command can always be executed.
/// </summary>
/// <param name="execute">The execution logic.</param>
public RelayCommand(Action<T> execute)
: this(execute, null)
{
}
/// <summary>
/// Initializes a new instance of the <see cref="RelayCommand<T>"/> class.
/// </summary>
/// <param name="execute">The execution logic.</param>
/// <param name="canExecute">The execution status logic.</param>
public RelayCommand(Action<T> execute, Predicate<T> canExecute)
{
if (execute == null)
throw new ArgumentNullException("execute");
_execute = execute;
_canExecute = canExecute;
}
#endregion
#region ICommand Members
public event EventHandler CanExecuteChanged
{
add
{
if (_canExecute != null)
CommandManager.RequerySuggested += value;
}
remove
{
if (_canExecute != null)
CommandManager.RequerySuggested -= value;
}
}
[DebuggerStepThrough]
public Boolean CanExecute(Object parameter)
{
return _canExecute == null ? true : _canExecute((T)parameter);
}
public void Execute(Object parameter)
{
_execute((T)parameter);
}
#endregion
}
/// <summary>
/// A command whose sole purpose is to relay its functionality to other objects by invoking delegates. The default return value for the CanExecute method is 'true'.
/// </summary>
public class RelayCommand : ICommand
{
#region Declarations
readonly Func<Boolean> _canExecute;
readonly Action _execute;
#endregion
#region Constructors
/// <summary>
/// Initializes a new instance of the <see cref="RelayCommand<T>"/> class and the command can always be executed.
/// </summary>
/// <param name="execute">The execution logic.</param>
public RelayCommand(Action execute)
: this(execute, null)
{
}
/// <summary>
/// Initializes a new instance of the <see cref="RelayCommand<T>"/> class.
/// </summary>
/// <param name="execute">The execution logic.</param>
/// <param name="canExecute">The execution status logic.</param>
public RelayCommand(Action execute, Func<Boolean> canExecute)
{
if (execute == null)
throw new ArgumentNullException("execute");
_execute = execute;
_canExecute = canExecute;
}
#endregion
#region ICommand Members
public event EventHandler CanExecuteChanged
{
add
{
if (_canExecute != null)
CommandManager.RequerySuggested += value;
}
remove
{
if (_canExecute != null)
CommandManager.RequerySuggested -= value;
}
}
[DebuggerStepThrough]
public Boolean CanExecute(Object parameter)
{
return _canExecute == null ? true : _canExecute();
}
public void Execute(Object parameter)
{
_execute();
}
#endregion
}
}
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