C# AE放大缩小地图全局显示功能

基于ArcGIS Base Command模板放大缩小

[地址]http://blog.csdn.net/eof_2011/article/details/8014075

 既能拉框也能点击放大缩小，原作者写的非常好收藏了。

基于ESRI.ArcGIS.Controls命名空间

这种esriControlsMousePointer方式实现的放大缩小只能拉框不能点击

放大

//写在功能按钮中
axMapControl1.MousePointer=esriControlsMousePointer.esriPointerZoomIn;
flag= a number //以flag number来判断 
//写在OnMouseDown之类的事件中 下同
IEnvelope pEnvelope = axMapControl1.TrackRectangle();
axMapControl1.Extent = pEnvelope ;

缩小

 axMapControl1.MousePointer = esriControlsMousePointer.esriPointerZoomOut;

pEnvelope = axMapControl1.TrackRectangle();
pEnvelope = axMapControl1.Extent;
pEnvelope .Expand(2, 2, true);
axMapControl1.Extent = pEnvelope ;

漫游

axMapControl1.MousePointer = esriControlsMousePointer.esriPointerPan;

pEnvelope = axMapControl1.Extent;
axMapControl1.Pan();

全局显示

axMapControl1.Extent = axMapControl1.FullExtent;

Tips：

可以根据flag来if判断写何种类型操作之后的代码

 基于IEnvolope的Expand方法

这种方法只能拉框放大

 private void Zoom_Out(AxMapControl map) 
 {
     var _map = axMapControl1;
     _map.Extent = _map.FullExtent;
     IEnvelope pEnvelope = null;
     pEnvelope = _map.Extent;
     pEnvelope.Expand(0.5, 0.5, true);
     _map.Extent = pEnvelope;
     //_map.MousePointer = esriControlsMousePointer.esriPointerDefault; 
     _map.ActiveView.Refresh();
 }

//ZoomIn放大
 private void Zoom_In()
 {
     IActiveView pAtView = axMapControl1.ActiveView;
     IPoint centerPoint = new PointClass();
     centerPoint.PutCoords((pAtView.Extent.XMin + pAtView.Extent.XMax) * 2, (pAtView.Extent.YMax + pAtView.Extent.YMin) * 2);
     IEnvelope pEnvlope = pAtView.Extent;
     pEnvlope.Expand(1.5, 1.5, true); 与放大的区别在于参数不同
     pAtView.Extent.CenterAt(centerPoint);
     pAtView.Extent = pEnvlope;
     pAtView.Refresh();

 }

 基于IEnvolope的Expand方法还有下面写法。

//这些写在放大按钮事件里
Property.axMapControl.CurrentTool = null;
pMouseOperate = "ZoomIn";
Property.axMapControl.MousePointer = esriControlsMousePointer.esriPointerZoomIn;
//同理 缩小的
 mainMapControl.CurrentTool = null;
pMouseOperate = "ZoomOut";
mainMapControl.MousePointer = esriControlsMousePointer.esriPointerZoomOut;

//这些方法axMapControl中鼠标按下事件中
//屏幕坐标点转化为地图坐标点
pPointPt = (mainMapControl.Map as IActiveView).ScreenDisplay.DisplayTransformation.ToMapPoint(e.x, e.y);

if (e.button == 1)
{
	IActiveView pActiveView = mainMapControl.ActiveView;
	IEnvelope pEnvelope = new EnvelopeClass();

	switch (pMouseOperate)
	{
		#region 拉框放大

		case "ZoomIn":
			pEnvelope = mainMapControl.TrackRectangle();
			//如果拉框范围为空则返回
			if (pEnvelope == null || pEnvelope.IsEmpty || pEnvelope.Height == 0 || pEnvelope.Width == 0)
			{
				return;
			}
			//如果有拉框范围，则放大到拉框范围
			pActiveView.Extent = pEnvelope;
			pActiveView.Refresh();
			break;

			#endregion

		#region 拉框缩小

		case "ZoomOut":
			pEnvelope = mainMapControl.TrackRectangle();

			//如果拉框范围为空则退出
			if (pEnvelope == null || pEnvelope.IsEmpty || pEnvelope.Height == 0 || pEnvelope.Width == 0)
			{
				return;
			}
				//如果有拉框范围，则以拉框范围为中心，缩小倍数为：当前视图范围/拉框范围
			else
			{
				double dWidth = pActiveView.Extent.Width*pActiveView.Extent.Width/pEnvelope.Width;
				double dHeight = pActiveView.Extent.Height*pActiveView.Extent.Height/pEnvelope.Height;
				double dXmin = pActiveView.Extent.XMin -
							   ((pEnvelope.XMin - pActiveView.Extent.XMin)*pActiveView.Extent.Width/
								pEnvelope.Width);
				double dYmin = pActiveView.Extent.YMin -
							   ((pEnvelope.YMin - pActiveView.Extent.YMin)*pActiveView.Extent.Height/
								pEnvelope.Height);
				double dXmax = dXmin + dWidth;
				double dYmax = dYmin + dHeight;
				pEnvelope.PutCoords(dXmin, dYmin, dXmax, dYmax);
			}
			pActiveView.Extent = pEnvelope;
			pActiveView.Refresh();
			break;

			#endregion
	}
}