Use TypeName Instead of TypeOf…Is

To write reusable routines that work with multiple types of controls, test the control type using the TypeName function in place of the TypeOf…Is statement. For example, take a look at this routine-you can reuse it in another project only if you also add the RichTextBox control to the Components list:

 ' save the selected text to an open file' works with TextBox and RichTextBox controlsSub SaveSelectedText(ctrl As Control, filenum As Integer)	If TypeOf ctrl Is TextBox Then		Print #filenum, ctrl.SelText	ElseIf TypeOf ctrl Is RichTextBox Then		Print #filenum, RichTextBox1.SelRTF	End IfEnd Sub

To avoid this problem and gain additional benefits such as the ability to use a Select Case block, use the TypeName function instead:

 Sub SaveSelectedText(ctrl As Control, filenum As Integer)	Select Case TypeName(ctrl)		Case "TextBox"			Print #filenum, ctrl.SelText		Case "RichTextBox"			Print #filenum, RichTextBox1.SelRTF	End SelectEnd Sub
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