ImageAreaBaseOnDrawImage Method

This raises the image area DrawImage event

Definition

Namespace: EWSoftware.ImageMaps.Windows.Forms
Assembly: EWSoftware.ImageMaps.Windows.Forms (in EWSoftware.ImageMaps.Windows.Forms.dll) Version: 2024.12.31.0

C#View Source Request Example

protected virtual void OnDrawImage(
	DrawImageEventArgs e
)

VBView Source Request Example

Protected Overridable Sub OnDrawImage ( 
	e As DrawImageEventArgs
)

C++View Source Request Example

protected:
virtual void OnDrawImage(
	DrawImageEventArgs^ e
)

F#View Source Request Example

abstract OnDrawImage : 
        e : DrawImageEventArgs -> unit 
override OnDrawImage : 
        e : DrawImageEventArgs -> unit

Parameters

e DrawImageEventArgs: The event arguments

Example

This is an example of an owner drawn image area event handler. For some other examples, see the demo application. As shown, the image area event properties are not accessible in the designer so you must write code to connect the event handlers. For example, add the code in the form's constructor after the call to InitializeComponent.

public ImageMapEventsForm()
{
    InitializeComponent();

    // Hook up the event handlers.  Since they are not accessible in the
    // designer, we must do it manually.
    ImageAreaBase a = (ImageAreaBase)imMap.Areas[4];
    a.DrawImage += Button_DrawImage;

    a = (ImageAreaBase)imMap.Areas[5];
    a.DrawImage += Button_DrawImage;

    a = (ImageAreaBase)imMap.Areas[6];
    a.DrawImage += Button_DrawImage;

    .
    .
    .
}


/// <summary>
/// Draw the "button" image areas
/// </summary>
/// <param name="sender">The sender of the event (the image area)</param>
/// <param name="e">The event arguments</param>
private void Button_DrawImage(object sender, DrawImageEventArgs e)
{
    ImageAttributes ia;
    Graphics g = e.Graphics;

    // All are ellipse image areas
    ImageAreaEllipse a = (ImageAreaEllipse)sender;
    Rectangle r = a.Ellipse;

    // Offset the area rectangle by the draw event offset
    r.Offset(e.ImageOffset.X, e.ImageOffset.Y);

    if(!a.Enabled)
        ia = iaDisabled;
    else
        ia = iaNormal;

    using TextureBrush tb = new(imgFiller, new Rectangle(0, 0, imgFiller.Width, imgFiller.Height), ia);

    tb.WrapMode = WrapMode.Tile;

    // Translate the brush coordinates to account for the offset
    using Matrix m = new();

    m.Translate(r.X, r.Y);
    tb.Transform = m;

    // If the area is focused or hot lighted, give it a glow effect
    if(e.DrawState == DrawState.Focus || e.DrawState == DrawState.HotLight)
    {
        using GraphicsPath pth = new();

        pth.AddEllipse(r);

        using PathGradientBrush pgb = new(pth);
        pgb.CenterColor = Color.LightSteelBlue;

        if(e.DrawState == DrawState.Focus)
            pgb.SurroundColors = [Color.Yellow];
        else
            pgb.SurroundColors = [Color.Blue];

        pgb.FocusScales = new PointF(0.8f, 0.8f);

        g.FillEllipse(pgb, r);
    }

    // Draw the filler
    g.FillEllipse(tb, r);
    g.DrawString((string)a.Tag, buttonFont, Brushes.Black, r, sfFormat);
}

Public Sub New()
    MyBase.New()

    InitializeComponent()

    ' Hook up the event handlers.  Since they are not accessible in the
    ' designer, we must do it manually.
    Dim a As ImageAreaBase = DirectCast(imMap.Areas(4), ImageAreaBase)

    AddHandler a.DrawImage, AddressOf Button_DrawImage

    a = DirectCast(imMap.Areas(5), ImageAreaBase)
    AddHandler a.DrawImage, AddressOf Button_DrawImage

    a = DirectCast(imMap.Areas(6), ImageAreaBase)
    AddHandler a.DrawImage, AddressOf Button_DrawImage
    .
    .
    .

End Sub


''' <summary>
''' Draw the "button" image areas
''' </summary>
''' <param name="sender">The sender of the event (the image area)</param>
''' <param name="e">The event arguments</param>
Private Sub Button_DrawImage(sender As Object, e As DrawImageEventArgs)
    Dim ia As ImageAttributes
    Dim g As Graphics = e.Graphics

    ' All are ellipse image areas
    Dim a As ImageAreaEllipse = DirectCast(sender, ImageAreaEllipse)
    Dim r As Rectangle = a.Ellipse

    ' Offset the area rectangle by the draw event offset
    r.Offset(e.ImageOffset.X, e.ImageOffset.Y)

    If Not a.Enabled Then
        ia = iaDisabled
    Else
        ia = iaNormal
    End If

    Using tb As New TextureBrush(imgFiller, _
      New Rectangle(0, 0, imgFiller.Width, imgFiller.Height), ia)
        tb.WrapMode = WrapMode.Tile

        ' Translate the brush coordinates to account for the offset
        Using m As New Matrix()
            m.Translate(CType(r.X, Single), CType(r.Y, Single))
            tb.Transform = m

            ' If the area is focused or hot lighted, give it a glow effect
            If e.DrawState = DrawState.Focus Or e.DrawState = DrawState.HotLight Then
                Using pth As New GraphicsPath()
                    pth.AddEllipse(r)

                    Using pgb As New PathGradientBrush(pth)
                        pgb.CenterColor = Color.LightSteelBlue

                        If e.DrawState = DrawState.Focus Then
                            pgb.SurroundColors = New Color() { Color.Yellow }
                        Else
                            pgb.SurroundColors = New Color() { Color.Blue }
                        End If

                        pgb.FocusScales = New PointF(0.8!, 0.8!)

                        g.FillEllipse(pgb, r)
                    End Using
                End Using
            End If

            ' Draw the filler
            g.FillEllipse(tb, r)
            g.DrawString(DirectCast(a.Tag, String), buttonFont, Brushes.Black, _
                New RectangleF(CType(r.X, Single), CType(r.Y, Single), _
                CType(r.Width, Single), CType(r.Height, Single)), sfFormat)
        End Using
    End Using
End Sub

C++

No code example is currently available or this language may not be supported.

No code example is currently available or this language may not be supported.

ImageAreaBaseOnDrawImage Method

Definition

Parameters

Example

See Also

Reference