Hi koenyn,
Text property of textbox is getting or setting the text contents of the textbox. So if modify the text property will change the contents displayed in the textbox. Thisdoesn't like the markedtextbox control. Why not use maskedtextbox,maskedtextbox will be more convenient to expand. If you want to use text box to implemet this function, you will need to filter the string.
Best regards,
Ling Wang
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