Renderer.Draw Method

Renderer.Draw Method

Draws the Strokes collection on the specified Graphics surface.

Definition

Visual Basic .NET	Public Sub Draw( _ ByVal g As Graphics, _ ByVal strokes As Strokes _ )
C#	public void Draw( Graphics g, Strokes strokes );
Managed C++	public: void Draw( Graphics *g, Strokes *strokes );

Parameters

g	System.Drawing.Graphics. The Graphics object with which to draw.
strokes	Microsoft.Ink.Strokes. The Strokes collection to draw.

Exceptions

ArgumentNullException : The caller does not specify the Strokes collection.

Remarks

Security Alert: For managed code, use the appropriate overload that accepts a Graphics object instead of the one that accepts an IntPtr ; otherwise, you need to hold on to the handle in such a way that results in a memory leak. The overloads that accept an hdc parameter are useful if you are using resources that are unmanaged code.

The pen width is adjusted appropriately, based on how you use SetViewTransform method. Specifically, the pen width is multiplied (or scaled) by the square root of the determinant of the view transform.

Note: If you have not set the pen width explicitly, it is 53 by default. You must multiply the pen width by the square root of the determinant to yield the correct bounding box. The height and width of the bounding box are expanded by half this amount in each direction.

For example, consider that the pen width is 53, the square root of the determinant is 50, and the bounding box is (0,0,1000,1000). The pen width adjustment to the bounding box in each direction is calculated as (53*50)/2, and the right and bottom sides are incremented by one. This results in a rendered bounding box of (-1325,-1325,2326,2326).

The Renderer object forces the viewport and window origins to 0,0. Any existing settings are saved and restored, but are not used by the Renderer. To perform scrolling, use the Renderer object's GetViewTransform and GetObjectTransform methods.

Examples

[C#]

This C# example takes the Strokes collection from an Ink object associated with an InkCollector object, theInkCollector, which is attached to a Panel , panelForInking. The example then calls the Draw method to draw the strokes onto a Graphics object attached to another Panel , panelForDrawing.

              using Microsoft.Ink;
...
// Members
private InkCollector theInkCollector;
private System.Windows.Forms.Panel panelForInking;
private System.Windows.Forms.Panel panelForDrawing;
...
// In the constructor...
    // Initialize InkCollector
    theInkCollector = new InkCollector(panelForInking.Handle);
    theInkCollector.Enabled = true;
    theInkCollector.Stroke += new InkCollectorStrokeEventHandler(theInkCollector_Stroke);

    // Paint event handler for drawing panel
    panelForDrawing.Paint += new PaintEventHandler(panelForDrawing_Paint);
...

private void theInkCollector_Stroke(object sender, InkCollectorStrokeEventArgs e)
{
    // Force a repaint on the drawing panel
    panelForDrawing.Refresh();
}

private void panelForDrawing_Paint(object sender, PaintEventArgs e)
{
   // Draw the InkCollector's strokes
   theInkCollector.Renderer.Draw(e.Graphics, theInkCollector.Ink.Strokes);
}
            

[Visual Basic .NET]

This Microsoft® Visual Basic® .NET example takes the Strokes collection from an Ink object associated with an InkCollector object, theInkCollector, which is attached to a Panel , panelForInking. The example then calls the Draw method to draw the strokes onto a Graphics object attached to another Panel , panelForDrawing.

              Imports Microsoft.Ink
...
    'Initialize InkCollector in the Form's New subroutine
    theInkCollector = New InkCollector(PanelForInking.Handle)
    theInkCollector.Enabled = True
...
Friend WithEvents theInkCollector As InkCollector
Friend WithEvents PanelForInking As System.Windows.Forms.Panel
Friend WithEvents PanelForDrawing As System.Windows.Forms.Panel
...
Private Sub theInkCollector_Stroke(ByVal sender As Object, ByVal e As Microsoft.Ink.InkCollectorStrokeEventArgs) _
Handles theInkCollector.Stroke
    'Force a repaint on the PanelForDrawing
    PanelForDrawing.Refresh()
End Sub

Private Sub PanelForDrawing_Paint(ByVal sender As Object, ByVal e As System.Windows.Forms.PaintEventArgs) _
Handles PanelForDrawing.Paint
    ' Draw the InkCollector's strokes
    theInkCollector.Renderer.Draw(e.Graphics, theInkCollector.Ink.Strokes)
End Sub
            

See Also

• Renderer.SetViewTransform Method
• DrawingAttributes Class
• Strokes Class
• Stroke Class