public void ZoomOut()
{
PrjRectangleF _viewport = _mapcontrol.Viewport;
double zoomWidthAmount = _viewport.Width * panzoomFactor;
double zoomHeightAmount = _viewport.Height * panzoomFactor;
PrjRectangleF newViewport = _viewport;
newViewport.Inflate(zoomWidthAmount, zoomHeightAmount);
//
_mapcontrol.SetViewportByPrj(newViewport);
}
protected override void HandleRectBox(Point prjLeftUp, Point prjRightBottom)
{
PrjRectangleF rect = new PrjRectangleF();
rect.MinX = prjLeftUp.X;
rect.MaxX = prjRightBottom.X;
rect.MinY = prjRightBottom.Y;
rect.MaxY = prjLeftUp.Y;
//
PrjRectangleF oldrect = _mapcontrol.Viewport;
double panzoomFactor = Math.Min(oldrect.Width / rect.Width, oldrect.Height / rect.Height);
double zoomWidthAmount = oldrect.Width * panzoomFactor;
double zoomHeightAmount = oldrect.Height * panzoomFactor;
//
rect.Inflate(zoomWidthAmount, zoomHeightAmount);
//
_mapcontrol.SetViewportByPrj(rect);
}