Form.FormBorderStyle Property
Gets or sets the border style of the form.
Namespace: System.Windows.Forms
Assembly: System.Windows.Forms (in System.Windows.Forms.dll)
Property Value
Type: System.Windows.Forms.FormBorderStyleA FormBorderStyle that represents the style of border to display for the form. The default is FormBorderStyle.Sizable.
| Exception | Condition |
|---|---|
| InvalidEnumArgumentException | The value specified is outside the range of valid values. |
The border style of the form determines how the outer edge of the form appears. In addition to changing the border display for a form, certain border styles prevent the form from being sized. For example, the FormBorderStyle.FixedDialog border style changes the border of the form to that of a dialog box and prevents the form from being resized. The border style can also affect the size or availability of the caption bar section of a form.
 Note |
|---|
With the Sizable style, it is impossible to resize the window below a certain minimum value, even if you have set ControlBox to false and assigned a zero-length string to Text. Consider working around this by using the SizableToolWindow style instead. |
The following code example creates a new instance of a Form and calls the ShowDialog method to display the form as a dialog box. The example sets the FormBorderStyle, AcceptButton, CancelButton, MinimizeBox, MaximizeBox, and StartPosition properties to change the appearance and functionality of the form to a dialog box. The example also uses the Add method of the form's Controls collection to add two Button controls. The example uses the HelpButton property to display a help button in the caption bar of the dialog box.
public void CreateMyForm() { // Create a new instance of the form. Form form1 = new Form(); // Create two buttons to use as the accept and cancel buttons. Button button1 = new Button (); Button button2 = new Button (); // Set the text of button1 to "OK". button1.Text = "OK"; // Set the position of the button on the form. button1.Location = new Point (10, 10); // Set the text of button2 to "Cancel". button2.Text = "Cancel"; // Set the position of the button based on the location of button1. button2.Location = new Point (button1.Left, button1.Height + button1.Top + 10); // Set the caption bar text of the form. form1.Text = "My Dialog Box"; // Display a help button on the form. form1.HelpButton = true; // Define the border style of the form to a dialog box. form1.FormBorderStyle = FormBorderStyle.FixedDialog; // Set the MaximizeBox to false to remove the maximize box. form1.MaximizeBox = false; // Set the MinimizeBox to false to remove the minimize box. form1.MinimizeBox = false; // Set the accept button of the form to button1. form1.AcceptButton = button1; // Set the cancel button of the form to button2. form1.CancelButton = button2; // Set the start position of the form to the center of the screen. form1.StartPosition = FormStartPosition.CenterScreen; // Add button1 to the form. form1.Controls.Add(button1); // Add button2 to the form. form1.Controls.Add(button2); // Display the form as a modal dialog box. form1.ShowDialog(); }
Windows 8, Windows Server 2012, Windows 7, Windows Vista SP2, Windows Server 2008 (Server Core Role not supported), Windows Server 2008 R2 (Server Core Role supported with SP1 or later; Itanium not supported)
The .NET Framework does not support all versions of every platform. For a list of the supported versions, see .NET Framework System Requirements.
