GroupBoxRenderer Class


Provides methods used to render a group box control with or without visual styles. This class cannot be inherited.

Namespace:   System.Windows.Forms
Assembly:  System.Windows.Forms (in System.Windows.Forms.dll)


Public NotInheritable Class GroupBoxRenderer


Gets or sets a value indicating whether the renderer uses the application state to determine rendering style.

System_CAPS_pubmethodSystem_CAPS_staticDrawGroupBox(Graphics, Rectangle, GroupBoxState)

Draws a group box control in the specified state and bounds.

System_CAPS_pubmethodSystem_CAPS_staticDrawGroupBox(Graphics, Rectangle, String, Font, Color, GroupBoxState)

Draws a group box control in the specified state and bounds, with the specified text, font, and color.

System_CAPS_pubmethodSystem_CAPS_staticDrawGroupBox(Graphics, Rectangle, String, Font, Color, TextFormatFlags, GroupBoxState)

Draws a group box control in the specified state and bounds, with the specified text, font, color, and text formatting.

System_CAPS_pubmethodSystem_CAPS_staticDrawGroupBox(Graphics, Rectangle, String, Font, GroupBoxState)

Draws a group box control in the specified state and bounds, with the specified text and font.

System_CAPS_pubmethodSystem_CAPS_staticDrawGroupBox(Graphics, Rectangle, String, Font, TextFormatFlags, GroupBoxState)

Draws a group box control in the specified state and bounds, with the specified text, font, and text formatting.

System_CAPS_pubmethodSystem_CAPS_staticDrawParentBackground(Graphics, Rectangle, Control)

Draws the background of a control's parent in the specified area.


Determines whether the specified object is equal to the current object.(Inherited from Object.)


Serves as the default hash function. (Inherited from Object.)


Gets the Type of the current instance.(Inherited from Object.)


Indicates whether the background of the group box has any semitransparent or alpha-blended pieces.


Returns a string that represents the current object.(Inherited from Object.)

The GroupBoxRenderer class provides a set of static methods that can be used to render a group box control. Rendering a control refers to drawing the user interface of a control. To draw a group box, use one of the DrawGroupBox methods. These methods provide a variety of text drawing options.

If visual styles are enabled in the operating system and visual styles are applied to the current application, DrawGroupBox will draw the group box with the current visual style. Otherwise, DrawGroupBox will draw the group box with the classic Windows style. This is useful if you are drawing a custom control that should automatically match the current visual style setting of the operating system.

This class wraps the functionality of a System.Windows.Forms.VisualStyles.VisualStyleRenderer that is set to one of the elements exposed by the System.Windows.Forms.VisualStyles.VisualStyleElement.Button.GroupBox class. For more information, see Rendering Controls with Visual Styles.


Visual styles are supported only on these platforms.

The following code example demonstrates how to create a custom control that uses the DrawGroupBox method to draw a group box with a double border if visual styles are enabled.

Imports System
Imports System.Drawing
Imports System.Windows.Forms
Imports System.Windows.Forms.VisualStyles

Class Form1
    Inherits Form
    Private WithEvents button1 As Button

    Public Sub New() 
        Dim GroupBox1 As New CustomGroupBox()
        button1 = New Button()

        GroupBox1.Text = "Radio Button Display"
        Me.button1.Location = New System.Drawing.Point(185, 231)
        Me.button1.Size = New System.Drawing.Size(105, 23)
        Me.button1.Text = "Toggle Visual Styles"


        ' Add some radio buttons to test the CustomGroupBox.
        Dim count As Integer = 8
        Dim ButtonArray(count) As RadioButton
        Dim i As Integer
        For i = 0 To count
            ButtonArray(i) = New RadioButton()
            ButtonArray(i).Text = "Button " +(i + 1).ToString()
        Next i

        If Application.RenderWithVisualStyles Then
            Me.Text = "Visual Styles Enabled"
            Me.Text = "Visual Styles Disabled"
        End If

    End Sub 'NewNew

    <STAThread()>  _
    Shared Sub Main() 
        ' If you do not call EnableVisualStyles below, then 
        ' GroupBoxRenderer automatically detects this and draws
        ' the group box without visual styles.
        Application.Run(New Form1())

    End Sub 'Main

    ' Match application style and toggle visual styles off
    ' and on for the application.
    Private Sub button1_Click(ByVal sender As Object, ByVal e As EventArgs) _
        Handles button1.Click

        GroupBoxRenderer.RenderMatchingApplicationState = True

        Application.VisualStyleState = _
            Application.VisualStyleState Xor _

        If Application.RenderWithVisualStyles Then
            Me.Text = "Visual Styles Enabled"
            Me.Text = "Visual Styles Disabled"
        End If

    End Sub
End Class

Public Class CustomGroupBox
    Inherits Control
    Private innerRectangle As New Rectangle()
    Private state As GroupBoxState = GroupBoxState.Normal
    Private panel As New FlowLayoutPanel()

    Public Sub New() 
        Me.Size = New Size(200, 200)
        Me.Location = New Point(10, 10)
        Me.Text = "CustomGroupBox"
        Me.Font = SystemFonts.IconTitleFont

        innerRectangle.X = ClientRectangle.X + 5
        innerRectangle.Y = ClientRectangle.Y + 15
        innerRectangle.Width = ClientRectangle.Width - 10
        innerRectangle.Height = ClientRectangle.Height - 20

        panel.FlowDirection = FlowDirection.TopDown
        panel.Location = New Point(innerRectangle.X + 5, innerRectangle.Y + 5)
        panel.Size = New Size(innerRectangle.Width - 10, innerRectangle.Height - 10)

    End Sub 'NewNew

    ' Draw the group box in the current state.
    Protected Overrides Sub OnPaint(ByVal e As PaintEventArgs) 

        GroupBoxRenderer.DrawGroupBox(e.Graphics, ClientRectangle, Me.Text, Me.Font, state)

        ' Draw an additional inner border if visual styles are enabled.
        If Application.RenderWithVisualStyles Then
            GroupBoxRenderer.DrawGroupBox(e.Graphics, innerRectangle, state)
        End If

    End Sub 'OnPaint

    ' Pass added controls to the internal FlowLayoutPanel.
    Protected Overrides Sub OnControlAdded(ByVal e As ControlEventArgs) 

        ' Ensure that you do not add the panel itself.
        If e.Control IsNot Me.panel Then
        End If

    End Sub 'OnControlAdded
End Class 'CustomGroupBox

.NET Framework
Available since 2.0

Any public static ( Shared in Visual Basic) members of this type are thread safe. Any instance members are not guaranteed to be thread safe.

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