system other than pixels this means that you have to translate between world and device
coordinates before you set these value. You can use the Graphics.TransformPoints API to
do this as shown below.
g.TransformPoints(CoordinateSpace.Device, CoordinateSpace.World, ptScrollSize);GraphicsUnit is Inch, then with a Graphics object that represents a monitor screen you will
have translated values that come to about 100 pixels for every logical inch. Using this API
ensures that you are insulated from the underlying device. The values will be much higher
for printers.
refer earlier FAQ in this section on AutoScrolling implementation) will have to be in
logical coordinates and will hence have to translate between logical and device coordinates.
protected void OnHandlePaint(object sender, PaintEventArgs args)
{
Graphics g = args.Graphics;
g.PageUnit = GraphicsUnit.Inch;
// this will always be in pixels
Point[] ptAutoScrollPos = new Point[]{this.AutoScrollPosition};
// We have to convert the pixel value (device) to inches (logical..world)
g.TransformPoints(CoordinateSpace.World, CoordinateSpace.Device, ptAutoScrollPos);
// set up a simple translation so that we draw with respect to the doc bounds
// and not the physical bounds
g.TranslateTransform(ptAutoScrollPos[0].X, ptAutoScrollPos[0].Y);
g.DrawEllipse(_pen, _rectEllipse);
}be seen on the screen. Scroll around. Remember the logical units are in inches. You will
be looking at a huge ellipse!
Source: Syncfusion Staff
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