通过IMap中的get_layers()可以遍历MapControl中当前的图层。此方法可以通过指定UID对图层进行过滤或者分类。
1. 遍历矢量图层
public IEnumLayer GetFeatureLayers()
{
UID uid = new UIDClass();
uid.Value = "{40A9E885-5533-11d0-98BE-00805F7CED21}";//FeatureLayer
IEnumLayer layers = frmMap.m_mapCtrl.Map.get_Layers(uid, true);
return layers;
}
2. 遍历栅格图层
public IEnumLayer GetRasterLayers()
{
UID uid = new UIDClass();
uid.Value = "{D02371C7-35F7-11D2-B1F2-00C04F8EDEFF}";//RasterLayer
IEnumLayer layers = frmMap.m_mapCtrl.Map.get_Layers(uid, true);
return layers;
}
3.遍历其它图层
只要修改相应的UID即可。常见的数据类型的UID有：
{6CA416B1-E160-11D2-9F4E-00C04F6BC78E} IDataLayer （包括所有类型的图层）
{40A9E885-5533-11d0-98BE-00805F7CED21} IFeatureLayer
{E156D7E5-22AF-11D3-9F99-00C04F6BC78E} IGeoFeatureLayer
{34B2EF81-F4AC-11D1-A245-080009B6F22B} IGraphicsLayer
{5CEAE408-4C0A-437F-9DB3-054D83919850} IFDOGraphicsLayer
{0C22A4C7-DAFD-11D2-9F46-00C04F6BC78E} ICoverageAnnotationLayer
{EDAD6644-1810-11D1-86AE-0000F8751720} IGroupLayer
4. 通过图层名获取图层接口
在AE开发中，这是常用到的功能，配合上面的方法，很容易实现。
//获取矢量图层接口
public IFeatureLayer GetFeatureLayer(string layerName)
{
//get the layers from the maps
IEnumLayer layers = GetFeatureLayers();
layers.Reset();
ILayer layer = null;
while ((layer = layers.Next()) != null)
{
if (layer.Name == layerName)
return layer as IFeatureLayer;
}
return null;
}
//获取栅格图层接口
public IRasterLayer GetRasterLayer(string layerName)
{
//get the layers from the maps
IEnumLayer layers = GetRasterLayers();
layers.Reset();
ILayer layer = null;
while ((layer = layers.Next()) != null)
{
if (layer.Name == layerName)
return layer as IRasterLayer;
}
return null;
}
获取其它类型的图层接口，同此类似。