1 ILayer pLayer = axMapControl1.get_Layer(0); 2 ILayerEffects pLayerEffects = (ILayerEffects)pLayer; 3 pLayerEffects.Transparency = (short)0; 4 5 axMapControl1.ActiveView.Refresh();
pLayerEffects.Transparency值为0时，图层不透明；
pLayerEffects.Transparency值为100时，图层完全透明。
http://bbs.esrichina-bj.cn/ESRI/viewthread.php?tid=28026&extra=page%3D6
为mapcontrol中的图层设置透明度,布布扣,bubuko.com
原文：http://www.cnblogs.com/fatherZyl/p/3604528.html