Cast sender object in event handler using GetType().Name

Question

I have an event handler for a Textbox as well as for a RichTextBox. The code is identical, but

In handler #1 i do:

RichTextBox tb = (RichTextBox)sender 

In handler #2 accordingly:

TextBox tb = (TextBox)sender 

Doing so i can fully manipulate the sending control. What i want to know is how can i cast the sending object to Textbox or RichTextbox according to its type using

sender.GetType().Name 

and then create the control at runtime and work with it. That way i only need one event handler function: less code, less errors, easier to maintain and DRY :-)

Answer 1

You never have to cast. I used to think the same way when I started, this 'pattern' is incorrect, and not really logical.

Your best bet is to use something like:

if (sender is TextBox) {   TextBox tb = (TextBox)sender; } else if (sender is RichTextBox) {   RichTextBox rtb = (RichTextBox)sender; } else {   // etc } 

Answer 2

I know this is a very old post but in Framework 4 you can cast the sender as a Control:

Control cntrl = (Control)sender; cntrl.Text = "This is a " + sender.GetType().ToString(); 

Note you are only able to reference controls that all of the different controls have in common (ie Text).