How to: Create a Custom Image Button Control

[This documentation is for preview only, and is subject to change in later releases. Blank topics are included as placeholders.]

To create a button with an image, you must create a custom control that derives from the Windows Forms Control class.

To create a button with an image

  1. Create a class that derives from the System.Windows.Forms.Control class.

  2. Define properties in the class for button images that show a pressed and not pressed state.

  3. Use the Invalidate method to cause the form to repaint when the button is clicked.

  4. Override the OnPaint method to draw the custom control with the appropriate images.

This example contains a class that defines a PictureButton custom control. It creates an instance of the control on the form and defines bitmaps used by the control.

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

Public Class PictureButtonDemo
    Inherits System.Windows.Forms.Form

    Friend WithEvents PictureButton1 As New PictureButton

    Public Sub New()

        ' Display the OK close button.
        Me.MinimizeBox = False
        Me.Text = "Picture Button Demo"

        ' Create an instance of the PictureButton custom control.
        With PictureButton1
            .Parent = Me
            .Bounds = New Rectangle(10, 30, 150, 30)
            .ForeColor = Color.White
            .BackgroundImageValue = MakeBitmap(Color.Blue, _
                PictureButton1.Width, PictureButton1.Height)
            .PressedImageValue = MakeBitmap(Color.LightBlue, _
                PictureButton1.Width, PictureButton1.Height)
            .Text = "Click Me"
        End With
    End Sub

    ' Clean up any resources being used.
    Protected Overloads Overrides Sub Dispose(ByVal disposing As Boolean)
    End Sub

    ' Create a bitmap object and fill it with the specified color.   
    ' To make it look like a custom image, draw an ellipse in it.
    Function MakeBitmap(ByVal ButtonColor As Color, ByVal width As Integer, _
        ByVal height As Integer) As Bitmap

        Dim bmp As New Bitmap(width, height)
        Dim g As Graphics = Graphics.FromImage(bmp)
        g.FillRectangle(New SolidBrush(ButtonColor), 0, 0, bmp.Width, bmp.Height)
        g.DrawEllipse(New Pen(Color.LightGray), 3, 3, width - 6, height - 6)

        Return bmp
    End Function

    Shared Sub Main()
        Application.Run(New PictureButtonDemo)
    End Sub

    ' Because PictureButton inherits from Control, 
    ' you can use the default Click event.
    Private Sub PictureButton1_Click(ByVal sender As Object, ByVal e As EventArgs) _
        Handles PictureButton1.Click

        'Add code here to respond to button click. 

    End Sub

End Class

'Button with an image custom control.
Public Class PictureButton
    Inherits Control

    Private backgroundImg As Image
    Private pressedImg As Image
    Private pressed As Boolean = False

    ' Property for the background image to be drawn behind the button text.
    Public Property BackgroundImageValue() As Image
            Return Me.backgroundImg
        End Get
        Set(ByVal Value As Image)
            Me.backgroundImg = Value
        End Set
    End Property

    ' Property for the background image to be drawn behind the button text when
    ' the button is pressed.
    Public Property PressedImageValue() As Image
            Return Me.pressedImg
        End Get
        Set(ByVal Value As Image)
            Me.pressedImg = Value
        End Set
    End Property

    ' When the mouse button is pressed, set the "pressed" flag to true
    ' and ivalidate the form to cause a repaint.  The .NET Compact Framework
    ' sets the mouse capture automatically.
    Protected Overrides Sub OnMouseDown(ByVal e As MouseEventArgs)
        Me.pressed = True
    End Sub

    ' When the mouse is released, reset the "pressed" flag
    ' and invalidate to redraw the button in the unpressed state.
    Protected Overrides Sub OnMouseUp(ByVal e As MouseEventArgs)
        Me.pressed = False
    End Sub 

    ' Override the OnPaint method to draw the background image and the text.
    Protected Overrides Sub OnPaint(ByVal e As PaintEventArgs)
        If Me.pressed AndAlso (Me.pressedImg IsNot Nothing) Then
            e.Graphics.DrawImage(Me.pressedImg, 0, 0)
            e.Graphics.DrawImage(Me.backgroundImg, 0, 0)
        End If

        ' Draw the text if there is any.
        If Me.Text.Length > 0 Then
            Dim size As SizeF = e.Graphics.MeasureString(Me.Text, Me.Font)

            ' Center the text inside the client area of the PictureButton.
            e.Graphics.DrawString(Me.Text, Me.Font, New SolidBrush(Me.ForeColor), _
                (Me.ClientSize.Width - size.Width) / 2, _
                (Me.ClientSize.Height - size.Height) / 2)
        End If

        ' Draw a border around the outside of the   
        ' control to look like Pocket PC buttons.
        e.Graphics.DrawRectangle(New Pen(Color.Black), 0, 0, _
            Me.ClientSize.Width - 1, Me.ClientSize.Height - 1)

    End Sub
End Class

This example requires references to the following namespaces: