InkCollectorMouseDownEventHandler Delegate
Represents the method that handles the MouseDown event of an InkCollector object.
Namespace: Microsoft.Ink
Assembly: Microsoft.Ink (in Microsoft.Ink.dll)
Syntax
'Declaration
Public Delegate Sub InkCollectorMouseDownEventHandler ( _
sender As Object, _
e As CancelMouseEventArgs _
)
'Usage
Dim instance As New InkCollectorMouseDownEventHandler(AddressOf HandlerMethod)
public delegate void InkCollectorMouseDownEventHandler(
Object sender,
CancelMouseEventArgs e
)
public delegate void InkCollectorMouseDownEventHandler(
Object^ sender,
CancelMouseEventArgs^ e
)
JScript does not support delegates.
Parameters
sender
Type: System.ObjectThe source InkCollector object of this event.
e
Type: Microsoft.Ink.CancelMouseEventArgsThe CancelMouseEventArgs object that contains the event data.
Remarks
When you create an InkCollectorMouseDownEventHandler delegate, you identify the method that handles the event. To associate the event with your event handler, add an instance of the delegate to the event. The event handler is called whenever the event occurs, unless you remove the delegate. For performance reasons, the default event interest is off but is turned on automatically in managed code if you add an event handler.
To improve real-time ink performance, hide the mouse cursor while inking. To do so, hide the mouse cursor in the MouseDown event handler, and show the mouse cursor in the MouseUp event handler.
Note
Some controls rely on a specific relationship between MouseDown, MouseMove, and MouseUp events. Cancelling these events may have unanticipated results.
Examples
In this example, when the MouseDown event fires, a check is made to see if EditingMode is set to Select. If so, the HitTestSelection method is called to determine which part of the selection (if any) has been hit. If the hit occurs on any of the four main compass directions, as specified by the SelectionHitResult enumeration, the stroke objects that are selected are changed to a different color.
Private Sub mInkObject_MouseDown(ByVal sender As Object, ByVal e As CancelMouseEventArgs)
If InkOverlayEditingMode.Select = mInkObject.EditingMode Then
Select Case mInkObject.HitTestSelection(e.X, e.Y)
Case SelectionHitResult.North
ChangeSelectionColor(Color.Green)
Case SelectionHitResult.East
ChangeSelectionColor(Color.Red)
Case SelectionHitResult.South
ChangeSelectionColor(Color.Purple)
Case SelectionHitResult.West
ChangeSelectionColor(Color.Blue)
End Select
End If
End Sub
Private Sub ChangeSelectionColor(ByVal color As Color)
Dim DA As DrawingAttributes = mInkObject.DefaultDrawingAttributes.Clone()
DA.Color = color
mInkObject.Selection.ModifyDrawingAttributes(DA)
Using G As Graphics = CreateGraphics()
' Get the bounding box of the selection. The default is
' to include the width of the strokes in the calculation.
' The returned rectangle is measured in ink units.
Dim rInkUnits As Rectangle = mInkObject.Selection.GetBoundingBox()
' In selection mode, the selected strokes are drawn inflated
' GetBoundingBox() does not take this into account
' Rectangle rInkUnits is inflated to compensate
rInkUnits.Inflate(53, 53)
Dim topLeft As Point = rInkUnits.Location
Dim bottomRight As Point = rInkUnits.Location + rInkUnits.Size
' get a Renderer object to make the conversion
Dim R As Renderer = New Renderer()
' convert the points to pixels
R.InkSpaceToPixel(G, topLeft)
R.InkSpaceToPixel(G, bottomRight)
' create a rectangle that is in pixels
Dim rPixelUnits As Rectangle = _
New Rectangle(topLeft, New Size(bottomRight.X - topLeft.X, bottomRight.Y - topLeft.Y))
' Redraw the strokes
mInkObject.Draw(rPixelUnits)
End Using
End Sub
private void mInkObject_MouseDown(object sender, CancelMouseEventArgs e)
{
if (InkOverlayEditingMode.Select == mInkObject.EditingMode)
{
switch (mInkObject.HitTestSelection(e.X, e.Y))
{
case SelectionHitResult.North:
ChangeSelectionColor(Color.Green);
break;
case SelectionHitResult.East:
ChangeSelectionColor(Color.Red);
break;
case SelectionHitResult.South:
ChangeSelectionColor(Color.Purple);
break;
case SelectionHitResult.West:
ChangeSelectionColor(Color.Blue);
break;
}
}
}
private void ChangeSelectionColor(Color color)
{
DrawingAttributes DA = mInkObject.DefaultDrawingAttributes.Clone();
DA.Color = color;
mInkObject.Selection.ModifyDrawingAttributes(DA);
using (Graphics G = CreateGraphics())
{
// Get the bounding box of the selection. The default is
// to include the width of the strokes in the calculation.
// The returned rectangle is measured in ink units.
Rectangle rInkUnits = mInkObject.Selection.GetBoundingBox();
// In selection mode, the selected strokes are drawn inflated
// GetBoundingBox() does not take this into account
// Rectangle rInkUnits is inflated to compensate
rInkUnits.Inflate(53, 53);
Point topLeft = rInkUnits.Location;
Point bottomRight = rInkUnits.Location + rInkUnits.Size;
// get a Renderer object to make the conversion
Renderer R = new Renderer();
// convert the points to pixels
R.InkSpaceToPixel(G, ref topLeft);
R.InkSpaceToPixel(G, ref bottomRight);
// create a rectangle that is in pixels
Rectangle rPixelUnits =
new Rectangle(topLeft, new Size(bottomRight.X - topLeft.X, bottomRight.Y - topLeft.Y));
// Redraw the strokes
mInkObject.Draw(rPixelUnits);
}
}
Platforms
Windows 7, Windows Vista, Windows Server 2008 R2, Windows Server 2008
The .NET Framework and .NET Compact Framework do not support all versions of every platform. For a list of the supported versions, see .NET Framework System Requirements.
Version Information
.NET Framework
Supported in: 3.0