Disable Zoom

[Andrea De Luca]

Hi everybody.

How can I disable zooming with the Ctrl+Mouse?

[Yamini Sri Muthunagarajan]

Hi Andrea De Luca,

Currently, we don’t have direct API support to disable zoom in the WinForms PdfViewer. We are checking for any possible workaround and will update you on November 24, 2025.

Regards,
YaminiSri M

[Yamini Sri Muthunagarajan]

Hi Andrea De Luca,

To disable zoom using Ctrl + Mouse Wheel, we have created a sample workaround to achieve this in the code-behind. In this sample, we subscribe to the MouseWheel event, and inside the handler, we check the HandledMouseEventArgs and set Handled to true to disable zoom. We have also attached the sample for your reference. Please review it and let us know if you need any further assistance.

Regards,
YaminiSri M

Attachment: Form_Field_issue_e3c936b5.zip

[Andrea De Luca]

Hi, thanks for your reply.

I use Visual Basic so i've translated the code in:

   If ((ModifierKeys & Keys.Control) = Keys.Control) Then

       Dim handledArgs As HandledMouseEventArgs = e

       If (handledArgs IsNot Nothing) Then

           handledArgs.Handled = True

       End If

   End If

It works but only for e.delta <0 

[Yamini Sri Muthunagarajan]

Hi Andrea De Luca,

After further analysis, we found that ModifierKeys and Keys.Control are numeric values in VB.NET. To check if the Ctrl key is pressed, we need to use a bitwise AND operation. In VB.NET, the correct operator for bitwise AND is And, not &.

But we initially used &, which is a string concatenation operator in VB.NET. This caused the condition to fail, so the zoom was not disabled. When you replace & with And, the condition works correctly because it performs the intended bitwise comparison.

Here’s the correct code snippet:

If (ModifierKeys And Keys.Control) = Keys.Control Then

    Dim handledArgs As HandledMouseEventArgs = e

    If handledArgs IsNot Nothing Then

        handledArgs.Handled = True

    End If

End If

Please review it and let us know if you need any further assistance.

Regards,

YaminiSri M

[Andrea De Luca]

Fantastico!!
It was my fault 😒😒
Thank You very much. 

Your assistence is superb

[Yamini Sri Muthunagarajan]

Thanks for the update. We are glad to hear that our recommendations were helpful to you.

Regards,

YaminiSri M