public void ZoomRatio(double zoom_ratio, double x, double y)
{
if (zoom_ratio < 0)
{
return;
}
System.Windows.Point point = new System.Windows.Point(x, y);
System.Windows.Point center = new System.Windows.Point(0.0, 0.0);
point = new System.Windows.Point(point.X - this.Bg.ActualWidth / 2.0, point.Y - this.Bg.ActualHeight / 2.0);
System.Windows.Point point2 = point;
double x2 = point2.X + msi.ActualWidth / 2.0;
double y2 = point2.Y + msi.ActualHeight / 2.0;
System.Windows.Point elementPoint = new System.Windows.Point(x2, y2);
System.Windows.Point point3 = msi.ElementToLogicalPoint(elementPoint);
msi.ZoomAboutLogicalPoint(zoom_ratio / curscale, point3.X, point3.Y);
curscale = zoom_ratio;
}
//
// Summary:
// Enables a user to zoom in on a point of the System.Windows.Controls.MultiScaleImage.
//
// Parameters:
// zoomIncrementFactor:
// Specifies the zoom. This number is greater than 0. A value of 1 specifies
// that the image fit the allotted page size exactly. A number greater than
// 1 specifies to zoom in. If a value of 0 or less is used, failure is returned
// and no zoom changes are applied.
//
// zoomCenterLogical:
// the point on the System.Windows.Controls.MultiScaleImage
// that is zoomed in on. This is a logical point (its coordinates are between 0 and 1).
public static void ZoomAboutLogicalPoint(this MultiScaleImage img, double zoomIncrementFactor, Point zoomCenterLogical)
{
img.ZoomAboutLogicalPoint(zoomIncrementFactor, zoomCenterLogical.X, zoomCenterLogical.Y);
}