About the function“DrawPolygonEx” and how to Extract my map.

Apr 27, 2013 at 7:40 AM
now. i have a problem. i want to draw a polygon on my map and the polygon is out my map's extent. so ,i want extract my map with polygon with my map old extent.
map is ChinaMap (bou2_4p.shp);

Are there many people can help me ?
Apr 27, 2013 at 7:50 AM
like mfc have a function BitBlt.
arcgis Extract byMask;
Coordinator
May 1, 2013 at 12:21 PM
I'm not sure what you need.
Are you drawing a polygon which is larger that one of your layers?
And what do you want to extract?
May 2, 2013 at 2:26 AM
Edited May 2, 2013 at 2:59 AM
Yes , I am drawing a polygon which is larger my "china map" on the layer . I want to extract the china map fron the larger polygon along the irregular boundary of the map.
Coordinator
May 6, 2013 at 7:19 AM
You should first merge/dissolve all shapes of your china shapefile to get 1 shape.
Next you can clip that shape with your polygon to get the desired result.
May 7, 2013 at 12:56 AM
Good idea , but how to merge/dissolve all shapes of my china shapefile , and how to clip that shape with my polygon with code ?
For example , my china shapefile have 30 shapes , and the polygon is a lager rectangle;