[Solved] Easily Resize the "Type a Message" box

[Simon]

Is there a fairly easy way to control the size of the box used to type the message into please? Even better would be to have the ability to add (or turn on) a resize handle so the user can resize the Text box to their desired size. An 'auto resize to fit content' would be another winner if possible. I know these controls are very functional and I suspect most of what is asked here is already possible.

 

Thank you in advance...

 

Simon

[Nadya | Tech Support Engineer]

Hello, Simon,

Thank you for your interest in our RadChat component.

Yes, it is possible to apply a custom size for the input text area "Type a Message" box:  

this.radChat1.ChatElement.InputTextBox.MinSize = new Size(0,105);

At this moment, RadChat does not provide such functionality to add (or turn on) a resize handler to resize the input text box to the client's desired size. I found this a reasonable feature request and logged this on your behalf in our public backlog here: RadChat: Provide an option to resize the input text box.

You can cast your vote for it to increase its prioroty or add your comments to it.

Also, I would like to note that RadChat features a multi-line input editor that automatically grows as the user types, accommodating longer messages without requiring manual resizing. The input text box starts as a single line and expands vertically to auto-grow and fit the entered text in the input text area. More information about this is available here: WinForms Chat UI Features Multi-Line Input Editor

You can also configure the maximum input lines if you wish.

If you have any other questions, please let me know.

Regards,
Nadya | Tech Support Engineer
Progress Telerik

[Simon]

Hi Nadya,

Thank you for coming back to me on this one. The...

.ChatElement.InputTextBox.MinSize

...properties seem to come back as 0, 0 - therefore, setting new values seems to do nothing (using code like...

.ChatElement.InputTextBox.MinSize = New Size(0, 35)

Is it reliant on another property perhaps?

Thank you in advance.

Simon

[Nadya | Tech Support Engineer]

Hello, Simon,

You are right - with a smaller height like 35px, the height is not applied because setting the MinHeight property affects the minimum height. So, you can apply the MaxSize property instead with a new Size (0,35). For example:

this.radChat1.ChatElement.InputTextBox.MaxSize = new Size(0, 35);

Keep in mind that this height might be too narrow for all buttons to show correctly.

I would also like to note that, starting with our Q2 2026 release, the RadChat component has been revamped to support voice-to-text input. As a result, the three-dot button is now displayed on a second row by design.

If you're just getting started with the RadChat component, I recommend downloading the latest version and testing your application with it. This will allow you to evaluate the current appearance and behavior of the control, along with the latest improvements and features.

Regards,
Nadya | Tech Support Engineer
Progress Telerik