/// <summary>
/// 将指定路径下的要素图层加载到地图控件中
/// <para>可加载lyr/shp/mdb/gdb/dwg等多种数据源图层，允许的路径形式参考<see cref="FeatureClassEx.FromPath"/>方法</para>
/// </summary>
/// <param name="mapControl">地图控件</param>
/// <param name="layerPath">要素类图层的完整路径，允许的路径形式参考<see cref="FeatureClassEx.FromPath"/>方法</param>
public static void LoadFeatureLayer(this AxMapControl mapControl, string layerPath)
{
if (Path.GetExtension(layerPath) == ".lyr" && File.Exists(layerPath))
{
mapControl.AddLayerFromFile(layerPath);
return;
}
var featureClass = FeatureClassEx.FromPath(layerPath);
mapControl.AddLayer(new FeatureLayerClass {
FeatureClass = featureClass, Name = featureClass.AliasName
});
}
private void Test()
{
double sumRiverLength = 0.0;
FeatureClassEx.FromPath(@"c:\River.shp").QueryFeatures(@"XZQDM = '440000'",
feature => sumRiverLength += feature.ToDouble("RiverLength"));
var workspace = WorkspaceEx.GetWorkSpace(@"c:\World.mdb");
FeatureClassEx.FromPath(@"c:\World.mdb\river").CopyStruct(workspace, "NewRiver", "河流");
var connString = DbHelper.Dbf_OleDb4(@"c:\River.dbf");
var dbHelper = DbHelper.GetOleDbHelper(connString).ExcNonQuery(@"update River set Name = 'Pearl River' where RiverCode ='003'");
}
/// <summary>
/// 检查多个路径下的要素类的坐标系是否完全一致
/// </summary>
/// <param name="paths"></param>
/// <returns>若坐标系不一致则返回提示信息，一致则返回null</returns>
public static string CheckCoordinates(params string[] paths)
{
var classes = new List <IFeatureClass>();
foreach (var path in paths)
{
var featureClass = FeatureClassEx.FromPath(path);
if (featureClass != null)
{
classes.Add(featureClass);
}
}
return(SpatialRefOpt.CheckSpatialRef(classes, out var message) ? message : null);
}
/// <summary>
/// 检查路径下的要素类是否被占用
/// </summary>
/// <param name="path">要素类的完整路径，参考<see cref="FeatureClassEx.FromPath"/></param>
/// <param name="autoAddExtension">是否自动在路径末尾增加.shp/.mdb/.dwg后缀，以再次查找要素类</param>
/// <returns>若要素类被锁定则返回提示信息，要素类不存在或未锁定返回null，若检查失败抛出异常</returns>
public static string CheckClassLock(string path, bool autoAddExtension = false)
{
try
{
var featureClass = FeatureClassEx.FromPath(path, autoAddExtension);
if (featureClass == null)
{
return(null);
}
featureClass.CheckClassLock(out var message);
return(message);
}
catch (Exception ex) { throw new Exception($"打开或检查要素类是否锁定失败：{ex.Message}\r\n请检查要素类路径“{path}”无误", ex); }
}
/// <summary>
/// 设置地图显示范围
/// </summary>
/// <param name="map">地图</param>
/// <param name="mapFrameInfo">地图框信息</param>
protected virtual void SetMapExtent(IMap map, MapFrameInfo mapFrameInfo)
{
//若MapExtent不为null，则地图缩放至MapExtent指定的范围；否则查找LayerInfo.ZoomTo为True的图层来定位缩放
var activeView = map as IActiveView;
if (mapFrameInfo.MapExtent != null)
{
activeView.MapZoomTo(mapFrameInfo.MapExtent, 1.3);
}
else
{
var layerInfo = mapFrameInfo.LayerInfos.FirstOrDefault(v => v.ZoomTo);
if (layerInfo != null)
{
var featureClass = FeatureClassEx.FromPath(layerInfo.DataSource);
var geometries = featureClass.QueryGeometries(layerInfo.Definition);
activeView.MapZoomTo(geometries, 1.3);
}
}
}
/// <summary>
/// 多边形转点，将多边形要素类每个图斑的中心（重心）点存入新的点要素类中
/// </summary>
/// <param name="sourceClassPath"></param>
/// <param name="targeClassPath"></param>
/// <returns></returns>
public static IFeatureClass PolygonClassToPoint(string sourceClassPath, string targeClassPath)
{
var sourceClass = FeatureClassEx.FromPath(sourceClassPath);
return(sourceClass.PolygonClassToPoint(targeClassPath));
}
