private void GotoByPrj(PointF pt)
{
double cx = (_viewport.MinX + _viewport.MaxX) / 2;
double cy = (_viewport.MinY + _viewport.MaxY) / 2;
double offsetX = pt.x - cx;
double offsetY = pt.y - cy;
_viewport.Offset(offsetX, offsetY);
RefreshMap();
}
private void ComputePrjTransfrom()
{
PrjRectangleF newViewport = _viewport;
//如果_offsetX与_offsetY不为0，则表示地图正在漫游
newViewport.Offset(-_offsetX, _offsetY);
if (_onMapControlViewportChanged != null)
{
_onMapControlViewportChanged(this, _viewport, newViewport);
}
TranslateTransform translateMatrix = null;
ScaleTransform scaleMatrix = null;
if (_prj2PixelTransform == null)
{
TransformGroup tran = new TransformGroup();
translateMatrix = new TranslateTransform();
scaleMatrix = new ScaleTransform();
ScaleTransform negMatrix = new ScaleTransform();
negMatrix.ScaleX = 1;
negMatrix.ScaleY = -1;
tran.Children.Add(negMatrix);
tran.Children.Add(translateMatrix);
tran.Children.Add(scaleMatrix);
//
translateMatrix.X = -newViewport.MinX; //left
translateMatrix.Y = newViewport.MaxY; //top
scaleMatrix.ScaleX = 1d / _resolutionX;
scaleMatrix.ScaleY = 1d / _resolutionY;
//
_prj2PixelTransform = tran;
}
else
{
translateMatrix = (_prj2PixelTransform as TransformGroup).Children[1] as TranslateTransform;
scaleMatrix = (_prj2PixelTransform as TransformGroup).Children[2] as ScaleTransform;
//
translateMatrix.X = -newViewport.MinX;
translateMatrix.Y = newViewport.MaxY;
scaleMatrix.ScaleX = 1d / _resolutionX;
scaleMatrix.ScaleY = 1d / _resolutionY;
}
_pixel2PrjTransform = _prj2PixelTransform.Inverse as Transform;
}