Get textbox from Button Tag

Question

I try to get a TextBox from a Button.Tag.

I have X buttons and for every Button has a own TextBox.

Not I want one Click-Method for all buttons and get the correct TextBox from the Button.Tag, but this does not work.

Can someone help me with this?

 Dim Textbox As TextBox = CType(DirectCast(sender, Button).Tag, TextBox)
 Textbox.Text = ""

With this code I get the following exception:

System.InvalidCastException: "Das Objekt des Typs "System.String" kann nicht in Typ "System.Windows.Forms.TextBox" umgewandelt werden."

Answer 1

Your code tries to convert a String (name of the TextBox) into a TextBox, which won't work.

So you either have to assign the TextBox'es by code like this:

Button1.Tag = TextBox1
Button2.Tag = TextBox2
...

or find the TextBox by its name like this:

Dim Textboxname As String = DirectCast(sender, Button).Tag.ToString()
Dim Textbox As TextBox = DirectCast(Me.Controls.Find(Textboxname, True).First(), TextBox)
Textbox.Text = ""