I have a Windows Form with a RichTextBox on it. The content of the RichTextBox is written to a database field that ist limited to 64k data. For my purpose that is way more than enough text to store.

I have set the MaxLength property to avoid insertng more data than allowed.

rtcControl.MaxLength = 65536

Howevery, that only restricts the amount of characters that so is allowed to put in the text. But with the formatting overhead from the Rtf I can type more text than I should be allowed to. It even get's worse if I insert a large image, which dosn't increase the TextLength at all but the Rtf Length grows quite a lot.

At the moment I check the Length of the richttextboxes' Rtf property in the FormClosing event and display a message to the user if it's to large. However that is just a workaround because I want to disallow putting more data than allowed into the control (like in a textbox if you exceed the MaxLength property nothing is inserted into the control and you hear the default beep().

Any ideas how to achive this?

I already tried:

• using a custom control which extends the richtextbox and shadows th Rtf property to intercept the insertation. But it seems it isn't executed if I add text.

• Even the TextChanged Event does not fire if I type smth. in the control.