DrawImageEventArgs Class

This is a custom event arguments class for the 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

public class DrawImageEventArgs : EventArgs

VBView Source Request Example

Public Class DrawImageEventArgs
	Inherits EventArgs

C++View Source Request Example

public ref class DrawImageEventArgs : public EventArgs

F#View Source Request Example

type DrawImageEventArgs = 
    class
        inherit EventArgs
    end

Inheritance: Object EventArgs DrawImageEventArgs

Remarks

The event contains the graphics context, the drawing state of the item, an offset if the image is scrolled or centered, and a flag that can be use to indicate whether or not the base class should draw the default focus frame around the active image area.

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.

Constructors

DrawImageEventArgs

Constructor

Properties

DrawFocus	This property is used to get or set whether the image map should draw the default focus frame around the active image area.
DrawState	This property is used to get or set the state of the item to draw
Graphics	This read-only property is used to get the graphics context for drawing
ImageOffset	This read-only property is used to get the image offset

Methods

Equals	Determines whether the specified object is equal to the current object. (Inherited from Object)
Finalize	Allows an object to try to free resources and perform other cleanup operations before it is reclaimed by garbage collection. (Inherited from Object)
GetHashCode	Serves as the default hash function. (Inherited from Object)
GetType	Gets the Type of the current instance. (Inherited from Object)
MemberwiseClone	Creates a shallow copy of the current Object. (Inherited from Object)
ToString	Returns a string that represents the current object. (Inherited from Object)