为mapcontrol中的图层设置透明度

 ILayer pLayer = axMapControl1.get_Layer();
 ILayerEffects pLayerEffects = (ILayerEffects)pLayer;
 pLayerEffects.Transparency = (short);

 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。

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