ArcEngine 10.2 在WPF与Winform框架下 GroupLayer中添加图层的差异

为了实现ArcMap中下面的效果，一个图层组GroupLayer中添加几个图层。

ArcEngine 可以通过IGroupLayer来实现，代码如下。

IGroupLayer RouteGroupLayer = new GroupLayerClass();
RouteGroupLayer.Name = "Route Group Layer";
IFeatureLayer featureLayer = new FeatureLayerClass();
featureLayer.Name = "New Layer 1";
RouteGroupLayer.Add(featureLayer);
axMapControl1.AddLayer(RouteGroupLayer, 0);

上面代码实现的效果如下。

现在我们还需要在上面基础上在添加一个图层New Layer 2, 我们可以使用下面的代码。

IGroupLayer groupLayer = new GroupLayerClass();
groupLayer.Name = "New Group Layer";
IFeatureLayer featureLayer = new FeatureLayerClass();
featureLayer.Name = "New Layer 1";
groupLayer.Add(featureLayer);
axMapControl1.AddLayer(groupLayer, 0);
IFeatureLayer featureLayer2 = new FeatureLayerClass();
featureLayer2.Name = "New Layer 2";
groupLayer.Add(featureLayer2);

WinForm框架运行上面代码就是我们想要的结果。

但是，WPF框架运行上面代码的运行效果如下图，发现New Layer 2并没有添加到Route Group Layer中。

后来发现，WPF框架，还需要加上 axTOCControl.Update(); 才会出现我们想要的效果，但是这样，就表示我们的程序中必须添加axTOCControl控件，代码和效果如下。

IGroupLayer groupLayer = new GroupLayerClass();
groupLayer.Name = "Group Layer";
IFeatureLayer featureLayer = new FeatureLayerClass();
featureLayer.Name = "New Layer 1";
groupLayer.Add(featureLayer);
axMapControl1.AddLayer(groupLayer, 0);
IFeatureLayer featureLayer2 = new FeatureLayerClass();
featureLayer2.Name = "New Layer 2";
groupLayer.Add(featureLayer2);
axTOCControl.Update();  // 后添加代码

WPF框架，如果不想添加axTOCControl控件，实现插入New Layer 2就要借助 IMapLayers.InsertLayerInGroup方法，代码如下。

IGroupLayer groupLayer = new GroupLayerClass();
groupLayer.Name = "Group Layer";
IFeatureLayer featureLayer = new FeatureLayerClass();
featureLayer.Name = "New Layer 1";
groupLayer.Add(featureLayer);
axMapControl.AddLayer(groupLayer, 0);
IFeatureLayer featureLayer2 = new FeatureLayerClass();
featureLayer2.Name = "New Layer 2";
  
IMapLayers mapLayers = axMapControl.Map as IMapLayers;
//第一个是GroupLayer的图层，第二个参数是要插入到组中的图层，第四个参数是要插入的位置, 0为首位
mapLayers.InsertLayerInGroup(groupLayer, featureLayer2, true, 0);