A simple example in C # delegate and events

In other recent work, using winform project development is sometimes necessary to control the use of other threads created when multiple threads in parallel, or is required to use some of the information (the contents of a text box, button clicks, etc.) in the form of other, more use of delegates and events , so I wrote a simple example record it.

To use delegates, first of all I must declare

// declare a delegate 
Private  the delegate  void TestDelegate ( String the addText, the RichTextBox TEMP);
 // delegate variable 
Private TestDelegate Test { GET ; SET ;}

Because it is used in multi-threaded, so write a method call delegate delegate's statement in the thread

// call the delegate 
Private  void InvokeDelegate ( String addText, the RichTextBox the TEMP)
{
    if (temp != null && temp.InvokeRequired)
    {
        temp.BeginInvoke(this.test, new object[] { addText, temp });
    }
}

Commissioned variable instantiation in another thread and delegate invocation

test = new TestDelegate(AddText);
InvokeDelegate(_addText, _tempRichTextBox);

private void AddText(string addText, RichTextBox temp)
{
    temp.Text += addText + "\r\n";
}

The above is a simple example of the use of multiple threads commission to control the use of

And then look at an event for messaging between controls

At the outset delegates and events

// delegate 
public  delegate  void DelegateTest ( String text);
 // Events 
public  Event DelegateTest AddTextEvent;

Carried out (release event) Invoke the desired position for messaging

AddTextEvent?.Invoke(text);

In the call events (event subscription)

EventTest et = new EventTest();
et.AddTextEvent + = new EventTest.DelegateTest (Et_AddTextEvent);

private void Et_AddTextEvent(string text)
{
    this.testRichTextBox.Text += text + "\r\n";
}

C # event is mainly used for messaging (communication) between threads, using a publish - subscribe model. Event Event declared in the class, the class that contains the event to publish the event, called the Publisher , Publisher class ; receiving other classes of the event is to subscribe to the event, called up for Subscriber , the subscription class .

These are examples of using delegates and events in winform to communicate between threads.

Full version of the code on GitHub: https://github.com/hhhhhaleyLi/DelegateTest

A simple example in C # delegate and events

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