Introduction
Expression Bodied Functions and Properties are a feature of C# 6.0. The limitation of this technology is that there can be only a single statement, and even a simple if statement is still multiline.
Code
Here are the three extension methods I have created to execute a line of code:
public static void ExecuteIfTrue(this bool value, Action action)
{
if (value) action();
}
public static void ExecuteIfFalse(this bool value, Action action)
{
if (!value) action();
}
public static void Execute(this bool value, Action actionTrue, Action actionFalse = null)
{
if (value) actionTrue();
else actionFalse?.Invoke();
}
Using the Code
Here is a simple example of using one of these extension methods in a property:
private void DisplayMessageBox() => Flag.ExecuteIfTrue(
() => MessageBox.Show("The Flag is set to true"));
Another example using true and false lambda expressions:
public void Execute(object parameter) =>
(parameter != null).Execute(() => _action(parameter),() =>_action("-1") );
The Sample
The sample is a very simple program that only shows a MessageBox when the Button is clicked if the CheckBox is checked.
The extension methods are used in the ViewModel for the ICommand for the button, and in the RelayCommand class.
History
- 04/19/2016: Initial version
- 04/21/2016: Article update
