RotateTransform rotates an element clockwise by a specified angle about the
point. The RotateTransform object in WPF represents RotateTransform. The Angle
property represents the angle in degrees to rotate clockwise. The CenterX and
CenterY properties represent the X and Y coordinates of the center point. By
default, a ScaleTransform is centered at the point (0,0), which corresponds to
the upper-left corner of the rectangle.
The code
listed in Listing creates two rectangles with same position and sizes accept the
second rectangle is rotated at 45 degrees.
<Grid>
<!-- Original Rectangle -->
<Rectangle
Width="200"
Height="50"
Fill="Yellow"/>
<!-- Rectangle with
45 degrees rotation -->
<Rectangle
Width="200"
Height="50"
Fill="Blue"
Opacity="0.5">
<Rectangle.RenderTransform>
<RotateTransform
CenterX="0"
CenterY="0"
Angle="45" />
</Rectangle.RenderTransform>
</Rectangle>
</Grid>
The output
of Listing looks like Figure 1.
Figure 1
The following code snippet changes the values of CenterX and CenterY.
<Rectangle
Width="200"
Height="50"
Fill="Blue" Opacity="0.5"
Margin="61,27,117,184">
<Rectangle.RenderTransform>
<RotateTransform
CenterX="-50"
CenterY="50"
Angle="45" />
</Rectangle.RenderTransform>
</Rectangle>
The new
output of looks like Figure 2 where you can see the center point of second
rectangle is shifted from its original position.
Figure 2
The code
listed in Listing creates a RotateTransform object dynamically and set it as
RenderTransform property of a Rectangle. The output looks like Figure .
Private Sub
RotateTransformSample()
Dim originalRectangle
As New
Rectangle()
originalRectangle.Width = 200
originalRectangle.Height = 50
originalRectangle.Fill = Brushes.Yellow
LayoutRoot.Children.Add(originalRectangle)
Dim rotatedRectangle
As New
Rectangle()
rotatedRectangle.Width = 200
rotatedRectangle.Height = 50
rotatedRectangle.Fill = Brushes.Blue
rotatedRectangle.Opacity = 0.5
Dim rotateTransform1
As New
RotateTransform(45, -50, 50)
rotatedRectangle.RenderTransform = rotateTransform1
LayoutRoot.Children.Add(rotatedRectangle)
End Sub