IActiveView坐标转换

PageLayoutControl页面坐标与地理坐标的相互转换：

1， 页面坐标到地理坐标的转换分两步：

（1）将IPageLayout转为IActiveView，IActiveView.ScreenDisplay.DisplayTransformation.FromMapPoin(); 将页面坐标转为屏幕坐标；

（2）将FocusMap转为IActiveView，IActiveView.ScreenDisplay.DisplayTransformation.ToMapPoint(); 将屏幕坐标转为地理坐标。

2， 地理坐标转换为页面坐标也是分两步：

（1）将FocusMap转为IActiveView，IActiveView.ScreenDisplay.DisplayTransformation.FromMapPoint();将地理坐标转为屏幕坐标；

（2）将IPageLayout转为IActiveView，IActiveView.ScreenDisplay.DisplayTransformation.ToMapPoint();将屏幕坐标转为页面坐标。

此外，其IDisplayTransformation.FromPoints方法可以将point（1/72 inch） distance转为map distance；IDisplayTransformation.ToPoints方法可以将map distance转为point distance。



例1、屏幕坐标转为地理坐标：

public IPoint GetMapCoordinatesFromScreenCoordinates(IPoint screenPoint, IActiveView activeView)
        {
            if (screenPoint == null || screenPoint.IsEmpty || activeView == null)
            {
                return null;
            }
            IScreenDisplay screenDisplay = activeView.ScreenDisplay;
            IDisplayTransformation displayTransformation = screenDisplay.DisplayTransformation;

            return displayTransformation.ToMapPoint((System.Int32)screenPoint.X, (System.Int32)screenPoint.Y);
        }

例2、地理坐标转为屏幕坐标：

public IPoint GetScreenCoordinatesFromMapCoorindates(IPoint mapPoint, IActiveView activeView)
        {
            if (mapPoint == null || mapPoint.IsEmpty || activeView == null)
            {
                return null;
            }
            IScreenDisplay screenDisplay = activeView.ScreenDisplay;
            IDisplayTransformation displayTransformation = screenDisplay.DisplayTransformation;
            System.Int32 x;
            System.Int32 y;
            displayTransformation.FromMapPoint(mapPoint, out x, out y);
            IPoint returnPoint = new PointClass();
            returnPoint.PutCoords(x, y);
            return returnPoint;
        }