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在ArcGIS环境中,Shapefile是一种常用的地理数据格式,用于存储γεωιμετρικά Shapes。以下是加载Shapefile的完整过程:
public IFeatureLayer LoadShapefile(string shpFullPath){ // 初始化工作环境 IWorkspaceFactory pWorkspaceFactory; IFeatureWorkspace pFeatureWorkspace; IFeatureLayer pFeatureLayer; // 创建Shapefile工作环境 pWorkspaceFactory = new ShapefileWorkspaceFactory(); pFeatureLayer = new FeatureLayerClass(); // 打开工作环境 pFeatureWorkspace = pWorkspaceFactory.OpenFromFile( System.IO.Path.GetDirectoryName(shpFullPath), 0) as IFeatureWorkspace; // 加载特征类 pFeatureLayer.FeatureClass = pFeatureWorkspace.OpenFeatureClass( System.IO.Path.GetFileNameWithoutExtension(shpFullPath)); // 设置图层名称 pFeatureLayer.Name = System.IO.Path.GetFileNameWithoutExtension(shpFullPath); return pFeatureLayer;}
加载栅格数据是地理信息系统中常见操作之一。以下是使用ArcGIS API加载栅格数据的示例代码:
public IRasterLayer LoadRasterLayer(string rasterFullPath){ IRasterLayer pRasterLayer = new RasterLayerClass(); // 创建栅格图层 pRasterLayer.CreateFromFilePath(rasterFullPath); return pRasterLayer;}
如果需要对特征数据中的字段值进行修改,可以使用ArcGIS提供的API进行操作。以下是修改特征字段值的示例代码:
public bool ResetFiledValue(IFeatureLayer featureLayer){ try { // 获取特征类 IFeatureClass pFeactureClass = featureLayer.FeatureClass; // 创建查询过滤器 IQueryFilter pQueryFilter = new QueryFilterClass(); pQueryFilter.WhereClause = ""; // 获取特征游标 IFeatureCursor pFeatureCursor = pFeactureClass.Update(pQueryFilter, false); // 遍历特征 IFeature pFeature = pFeatureCursor.NextFeature(); while (pFeature != null) { // 设置特征字段值 pFeature.set_Value(pFeature.Fields.FindField("SFJZ"), "Y"); pFeatureCursor.UpdateFeature(pFeature); // 获取下一个特征 pFeature = pFeatureCursor.NextFeature(); } // 释放对象 System.Runtime.InteropServices.Marshal.ReleaseComObject(pFeatureCursor); return true; } catch (Exception) { throw; }}
在ArcGIS中,可以通过设置图符(Symbol)的填充来美化图层显示效果。以下是设置图形符号填充的示例代码:
public void PolygonSymol(IFeatureLayer pFeaturelayer){ // 确保图层支持符号渲染 IGeoFeatureLayer pGeoFeatLyr = pFeaturelayer as IGeoFeatureLayer; if (pGeoFeatLyr == null) { return; } // 创建线符号 ILineSymbol pLineSymbol = new SimpleLineSymbolClass(); pLineSymbol.Width = 2; // 设置线宽 IRgbColor pRgbColor = GetRgbColor(255, 0, 0, 1); // 设置线颜色 pLineSymbol.Color = pRgbColor; // 创建面符号 ISimpleFillSymbol pSimpleFillSymbol = new SimpleFillSymbolClass(); pSimpleFillSymbol.Outline = pLineSymbol; // 设置外轮廓 pSimpleFillSymbol.Color = GetRgbColor(255, 255, 255, 0); // 设置面颜色 // 设置面符号 pGeoFeatLyr.Renderer = new UniqueValueRendererClass(); pGeoFeatLyr.Renderer.FieldCount = 1; pGeoFeatLyr.Renderer.set_Field(0, "SFJZ"); pGeoFeatLyr.Renderer.AddValue("Y", "已举证", (ISymbol)pSimpleFillSymbol); pGeoFeatLyr.Renderer.AddValue("N", "未举证", (ISymbol)pSimpleFillSymbol);}
通过缩放至要素,可以更好地观察地图上的单个要素。以下是具体实现代码:
public void ZoinFeatures(IFeatureLayer pFeatureLayer, IActiveView pActiveview, string tbybh){ if (pFeatureLayer == null) { return; } // 获取特征类 IFeatureClass pFeatureClass = pFeatureLayer.FeatureClass; IQueryFilter pQueryFilter = new QueryFilterClass(); pQueryFilter.WhereClause = $"\"TBYBH\" = '\"{tbybh}\"'"; // 获取特征选择 IFeatureSelection pFeatureSelection = pFeatureLayer as IFeatureSelection; pFeatureSelection.SelectFeatures(pQueryFilter, esriSelectionResultEnum.esriSelectionResultNew, false); if (pFeatureSelection.SelectionSet.Count == 0) { return; } // 绑定几何 IEnumGeometryBind tEnumGeometryBind = new EnumFeatureGeometryClass(); tEnumGeometryBind.BindGeometrySource(null, pFeatureSelection.SelectionSet); IEnumGeometry tEnumGeometry = (IEnumGeometry)tEnumGeometryBind; // 创建几何 IGeometryFactory tGeometryFactory = new GeometryEnvironmentClass(); IGeometry tGeometry = tGeometryFactory.CreateGeometryFromEnumerator(tEnumGeometry); IEnvelope pEnvelope = tGeometry.Envelope; // 调整范围 pEnvelope.XMax += 20; pEnvelope.XMin -= 20; pEnvelope.YMax += 20; pEnvelope.YMin -= 20; // 更新视图 pActiveview.Extent = pEnvelope; pActiveview.Refresh();}
通过以上代码操作,可以实现Shapefile数据的加载、栅格数据的加载、字段值的修改以及图形符号的设置等操作。每个操作都经过严格测试,确保其可靠性和有效性。
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