[Solved] How does addition assignment operator behave

by


It adds an event handler to the event Click.
When Click event is raised all the handlers method added to it are called.

For example:

void BtnClickHandler1(object sender, EventArgs e)
{
    MessageBox.Show("BtnClickHandler1");
}

void BtnClickHandler2(object sender, EventArgs e)
{
    MessageBox.Show("BtnClickHandler2");
}

And you add these methods to Click event like this:

btn.Click += BtnClickHandler1
btn.Click += BtnClickHandler2

When button is clicked the methods will be called in the order you added them, so the message box will be:

BtnClickHandler1
BtnClickHandler2

If you want specific info about += operator, MSDN says:

The += operator is also used to specify a method that will be called
in response to an event; such methods are called event handlers. The
use of the += operator in this context is referred to as subscribing
to an event.

For more info look at:

https://msdn.microsoft.com/en-us/library/edzehd2t%28v=vs.110%29.aspx

http://www.dotnetperls.com/event

3

solved How does addition assignment operator behave