private 

void axMapControl1_OnMouseDown(

object sender, ESRI.ArcGIS.Controls.IMapControlEvents2_OnMouseDownEvent e)

        {

            

//

产生一个简单符号

            ISimpleMarkerSymbol pMarkerSymbol = 

new SimpleMarkerSymbolClass();

            pMarkerSymbol.Style = esriSimpleMarkerStyle.esriSMSCross;

            pMarkerSymbol.Color = GetRGBColor(

60, 

100, 

50);

            pMarkerSymbol.Angle = 

60;

            pMarkerSymbol.XOffset = 

10;

//

符号偏移鼠标点击点横坐标的距离

            pMarkerSymbol.YOffset = 

10;

//

符号偏移鼠标点击点纵坐标的距离

            

//

产生一个箭头符号

            IArrowMarkerSymbol pArrowMarker = 

new ArrowMarkerSymbolClass();

            pArrowMarker.Length = 

5;

//

箭头的顶点到底边的距离

            pArrowMarker.Width = 

10;

//

箭头的底边的宽度

            pArrowMarker.Color = GetRGBColor(

0, 

60, 

90);

            pArrowMarker.XOffset = -

10;

            pArrowMarker.YOffset = -

10;

            

//

产生一个叠加符号并把前面的符号加入

            IMultiLayerMarkerSymbol pMulMarker = 

new MultiLayerMarkerSymbolClass();

            pMulMarker.AddLayer(pArrowMarker);

            pMulMarker.AddLayer(pMarkerSymbol);

            IPoint pPoint = 

new PointClass();

            pPoint.PutCoords(e.mapX, e.mapY);

            

object o = (

object)pMulMarker;

            axMapControl1.DrawShape(pPoint, 

ref o);

        }

        

private IRgbColor GetRGBColor(

int red, 

int green, 

int blue)

        {

            IRgbColor pRgbColor = 

new RgbColorClass();

            pRgbColor.Red = red;

            pRgbColor.Green = green;

            pRgbColor.Blue = blue;

            

return pRgbColor;

        }

from:http://blog.sina.com.cn/s/blog_71d88f280100mj5z.html