创建内存图层不成功的问题
http://bbs.esrichina-bj.cn/ESRI/thread-47516-1-1.html
注意：创建图层时坐标系统不能为Unknow
我想把一图层中选中要素复制到一个新的图层中，故要先创建一个图层。目前网上有个创建内存图层的方法如下：
/// <summary>
/// 在内存中创建图层
/// </summary>
/// <param name="DataSetName">数据集名称（所建图层名称）</param>
/// <param name="AliaseName">别名</param>
/// <param name="SpatialRef">空间参考</param>
/// <param name="GeometryType">几何类型</param>
/// <param name="PropertyFields">属性字段集合</param>
/// <returns>IfeatureLayer</returns>
public static IFeatureLayer CreateFeatureLayerInmemeory(string DataSetName,
string AliaseName, ISpatialReference SpatialRef, esriGeometryType GeometryType, IFields PropertyFields)
{
IWorkspaceFactory workspaceFactory = new InMemoryWorkspaceFactoryClass();
ESRI.ArcGIS.Geodatabase.IWorkspaceName workspaceName = workspaceFactory.Create("", "MyWorkspace", null, 0);
ESRI.ArcGIS.esriSystem.IName name = (IName)workspaceName;
ESRI.ArcGIS.Geodatabase.IWorkspace inmemWor = (IWorkspace)name.Open();
IField oField = new FieldClass();
IFields oFields = new FieldsClass();
IFieldsEdit oFieldsEdit = null;
IFieldEdit oFieldEdit = null;
IFeatureClass oFeatureClass = null;
IFeatureLayer oFeatureLayer = null;
try
{
oFieldsEdit = oFields as IFieldsEdit;
oFieldEdit = oField as IFieldEdit;
for (int i = 0; i < PropertyFields.FieldCount; i++)
{
oFieldsEdit.AddField(PropertyFields.get_Field(i));
}
//IGeometryDef Interface Provides access to members that return information about the geometry definition
IGeometryDef geometryDef = new GeometryDefClass();
//IGeometryDefEdit Provides access to members that modify the geometry definition
IGeometryDefEdit geometryDefEdit = (IGeometryDefEdit)geometryDef;
geometryDefEdit.AvgNumPoints_2 = 5;
geometryDefEdit.GeometryType_2 = GeometryType;
geometryDefEdit.GridCount_2 = 1;
geometryDefEdit.HasM_2 = false;
geometryDefEdit.HasZ_2 = false;
geometryDefEdit.SpatialReference_2 = SpatialRef;
oFieldEdit.Name_2 = "SHAPE";
oFieldEdit.Type_2 = esriFieldType.esriFieldTypeGeometry;
oFieldEdit.GeometryDef_2 = geometryDef;
oFieldEdit.IsNullable_2 = true;
oFieldEdit.Required_2 = true;
oFieldsEdit.AddField(oField);
oFeatureClass = (inmemWor asIFeatureWorkspace).CreateFeatureClass(DataSetName, oFields, null, null,esriFeatureType.esriFTSimple, "SHAPE", "");
(oFeatureClass as IDataset).BrowseName = DataSetName;
oFeatureLayer = new FeatureLayerClass();
oFeatureLayer.Name = AliaseName;
oFeatureLayer.FeatureClass = oFeatureClass;
}
catch
{
MessageBox.Show("Error on Create FeatureLayer!");
}
finally
{
try
{
System.Runtime.InteropServices.Marshal.ReleaseComObject(oField);
System.Runtime.InteropServices.Marshal.ReleaseComObject(oFields);
System.Runtime.InteropServices.Marshal.ReleaseComObject(oFieldsEdit);
System.Runtime.InteropServices.Marshal.ReleaseComObject(oFieldEdit);
System.Runtime.InteropServices.Marshal.ReleaseComObject(name);
System.Runtime.InteropServices.Marshal.ReleaseComObject(workspaceFactory);
System.Runtime.InteropServices.Marshal.ReleaseComObject(workspaceName);
System.Runtime.InteropServices.Marshal.ReleaseComObject(inmemWor);
System.Runtime.InteropServices.Marshal.ReleaseComObject(oFeatureClass);
}
catch { }
GC.Collect();
}
return oFeatureLayer;
}复制代码
创建字段组的方法如下：
//Create fileds
public IFields CreateFields()
{
IFields fields = new FieldsClass();
// if (fields == null)
//{
fields = new FieldsClass();
// create the fields using the required fields method
IObjectClassDescription objectClassDescription = new ObjectClassDescriptionClass();
fields = objectClassDescription.RequiredFields;
ESRI.ArcGIS.Geodatabase.IFieldsEdit fieldsEdit = (ESRI.ArcGIS.Geodatabase.IFieldsEdit)fields; // Explicit Cast
ESRI.ArcGIS.Geodatabase.IField field = new ESRI.ArcGIS.Geodatabase.FieldClass();
// create a user defined text field
ESRI.ArcGIS.Geodatabase.IFieldEdit fieldEdit = (ESRI.ArcGIS.Geodatabase.IFieldEdit)field; // Explicit Cast
// setup field properties
fieldEdit.Name_2 = "SampleField";
fieldEdit.Type_2 = ESRI.ArcGIS.Geodatabase.esriFieldType.esriFieldTypeString;
fieldEdit.IsNullable_2 = true;
fieldEdit.AliasName_2 = "Sample Field Column";
fieldEdit.DefaultValue_2 = "test";
fieldEdit.Editable_2 = true;
fieldEdit.Length_2 = 100;
// add field to field collection
fieldsEdit.AddField(field);
fields = (ESRI.ArcGIS.Geodatabase.IFields)fieldsEdit; // Explicit Cast
return fields;
//}
//return null;
} 复制代码
我采用如下代码进行图层的创建：
IFields pField = CreateFields();
ISpatialReference pSparef = new UnknownCoordinateSystemClass();
IFeatureLayer pFeatLyr =CreateFeatureLayerInmemeory("Hello", "Hello", pSparef,esriGeometryType.esriGeometryPoint, pField);
this.m_mainForm.m_mapCtrl.Map.AddLayer(pFeatLyr);
this.m_mainForm.m_mapCtrl.ActiveView.Refresh();复制代码
但调试的时候，图层创建失败，即返回的IFeatureLayer是null。
//这个地方出错
IFeatureLayer pFeatLyr = CreateFeatureLayerInmemeory("Hello", "Hello", pSparef, esriGeometryType.esriGeometryPoint, pField);复制代码
希望能够得到大家的帮助，非常感谢！