Disable resizing of a Windows Forms form

How do I turn off the user's ability to resize a Windows Forms form?

I'm having it resize itself on a click.

Take a look at the FormBorderStyle property

form1.FormBorderStyle = FormBorderStyle.FixedSingle;

You may also want to remove the minimize and maximize buttons:

form1.MaximizeBox = false;
form1.MinimizeBox = false;

1. First, select the form.
2. Then, go to the properties menu.

3. And change the property "FormBorderStyle" from sizable to Fixed3D or FixedSingle.

   

More precisely, add the code below to the private void InitializeComponent() method of the Form class:

this.FormBorderStyle = System.Windows.Forms.FormBorderStyle.FixedSingle;

Explanation

By default, FormBorderStyle property has the sizable value FormBorderStyle.Sizable assigned. Which enables form to be resized.

There are 7 kinds of FormBorderStyle property values available to use.

• None
• FixedSingle
• Fixed3D
• FixedDialog
• Sizable
• FixedToolWindow
• SizableToolWindow

Depending upon the kind of form, we can assign the appropriate value accordingly. Assuming your form name is form1.

Choose any one from below to make it as Fixed

FixedSingle, Fixed3D, FixedDialog makes the form non-resizeable, assigning None will also work but won't make sense without a control box in case.

Code

Code snippets below, use any one of them

FixedSingle

    form1.FormBorderStyle = FormBorderStyle.FixedSingle;

Fixed3D

    form1.FormBorderStyle = FormBorderStyle.Fixed3D;

FixedDialog

    form1.FormBorderStyle = FormBorderStyle.FixedDialog;

None [Optional] Note: There'd no control box

    form1.FormBorderStyle = FormBorderStyle.None;

Or, Graphically

We can apply it graphically like this.

Make sure you've selected the form which you want to make it fixed size. then you'll see a property named FormBorderStyle property there in Properties window.