(Object sender, EventArgs e) Function

Sender is the object that generates events, and e is the parameter that generates events.

For example, the Label MouseClick event:
Private void label1_MouseClick (Object Sender, MouseEventArgs e)
{
Label senderLabel = (Label)Sender; // AccordingSenderReference controls.
SenderLabel. Text = e. Button. ToString (); // Based on the Button parameter in e, determine whether it is left or right-click.
}
Click your Label in the form to display the Rigle or Left mouse button you clicked.
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Take Button as an example:
Protected void button#click (Object Sender, EventArgs e)
TheSenderIs the button you click. You can get the reference of this button through type conversion:
Button sendButton = (Button)Sender;
E is the parameters of the click event.