由于工作需要，要求使用AE实现对某些气象观测要素（如气温、雨量）等进行IDW插值，经过这段时间的努力，基本功能已经实现。在此感谢一些网上的技术牛人，谢谢他们无私的分享（搜索是件快乐的事情），同时也要感谢自己付出的努力（智慧、查找资料、耐心）。实现过程大致如下：
- IDW插值
- 剪裁（单波段影像）
- 颜色渲染
- 出透明图
下面记录了实现的主要代码，毕竟好记性不如烂笔头。
（一）IDW空间插值的实现
1 private ESRI.ArcGIS.Geodatabase.IGeoDataset CreateRaster(string filedName, string pPath)
2 {
3 IMap pMap = this._mapControl.Map;
4 IInterpolationOp3 pInterpolationOp = new RasterInterpolationOpClass(); //IInterpolationOp目前已被IInterpolationOp3所取代
5 //定义工作空间
6 IWorkspaceFactory pWorkspaceFactory = new ShapefileWorkspaceFactory();
7 string pFolder = System.IO.Path.GetDirectoryName(pPath);
8 string pFileName = System.IO.Path.GetFileName(pPath);
9 IWorkspace pWorkspace = pWorkspaceFactory.OpenFromFile(pFolder, 0); //设定地理处理的工作空间
10 IFeatureWorkspace pFeatureWorkspace = pWorkspace as IFeatureWorkspace;
11 IFeatureClass oFeatureClass = pFeatureWorkspace.OpenFeatureClass(pFileName);
12 IFeatureClassDescriptor pFCDescriptor = new FeatureClassDescriptorClass();
13 pFCDescriptor.Create(oFeatureClass, null, filedName);
14 IRasterRadius pRadius = new RasterRadiusClass(); //设置搜索半径
15
16 object objectMaxDistance = null;
17 object objectbarrier = null;
18 object missing = Type.Missing;
19 pRadius.SetVariable(12, ref missing); //这里设置不同的值，出图的效果（如颜色的深浅等）就不同
20
21 //ESRI.ArcGIS.Geodatabase.IWorkspace pShpWorkspace = pWorkspaceFactory.OpenFromFile(tempPath, 0);
22
23 object dCellSize = 0.013; //设置栅格精度（输出栅格像元大小）
24 object snapRasterData = Type.Missing;
25 IRasterAnalysisEnvironment pEnv = pInterpolationOp as IRasterAnalysisEnvironment;
26 pEnv.SetCellSize(esriRasterEnvSettingEnum.esriRasterEnvValue, ref dCellSize);
27 pEnv.OutSpatialReference = pMap.SpatialReference;
28 //执行插置，产生结果（栅格数据集）
29 IGeoDataset poutGeoDataset = pInterpolationOp.IDW((IGeoDataset)pFCDescriptor, 2, pRadius, ref missing); //这里参数2为默认的权重值
30 //控制周围点对于内插值的重要性的距离指数。幂值越高，远数据点的影响会越小。
31 IRaster pOutRaster = poutGeoDataset as IRaster;
32
33 IRasterLayer pOutRasLayer = new RasterLayer();
34 pOutRasLayer.CreateFromRaster(pOutRaster); //生成栅格数据图层
35 this._mapControl.AddLayer(pOutRasLayer); //添加生成的图层
36
37 return poutGeoDataset; //返回一个GeoDataSet
38
39 }
（二）shp图层剪裁栅格数据
1 private IRaster ShpLayerClipRaster(IFeatureLayer featureLayer, IRaster raster) 2 { 3 IFeatureLayer pFeaLyr; 4 IRasterAnalysisEnvironment pEnv; 5 IGeoDataset pTempDS; 6 pFeaLyr = featureLayer; 7 pTempDS = pFeaLyr.FeatureClass as IGeoDataset; 8 IConversionOp pConOp = new RasterConversionOpClass(); 9 pEnv = pConOp as IRasterAnalysisEnvironment; 10 IRasterProps pProp; 11 pProp = raster as IRasterProps; 12 object cellSize = 0.01; 13 pEnv.SetCellSize(esriRasterEnvSettingEnum.esriRasterEnvValue, ref cellSize); 14 IRasterConvertHelper rsh = new RasterConvertHelperClass(); 15 IRaster tempRaster; 16 tempRaster = rsh.ToRaster1(pTempDS, "Grid", pEnv); 17 18 IRaster pOutRaster; 19 IExtractionOp pExtrOp = new RasterExtractionOpClass(); 20 pOutRaster = (IRaster)pExtrOp.Raster((IGeoDataset)raster, (IGeoDataset)tempRaster); 21 22 //pTempDS = null; 23 //pConOp = null; 24 //pFeaLyr = null; 25 26 return pOutRaster; 27 }
（三）栅格数据颜色分级渲染
实现思路如下：
1.定义渲染的一系列接口
2.判断图像是否建立了直方图，如果没有则进行创建
3.定义颜色序列，为渲染提供渲染的方案（自定义色带颜色包括透明效果色以及范围值区间）
4.调用Render方法进行渲染
1 private void classifyColorToRaster(IRasterLayer pRasterLayer, int classCount, int size) 2 { 3 IRasterClassifyColorRampRenderer classifyRender = new RasterClassifyColorRampRenderer(); 4 IRasterRenderer rasterRender = classifyRender as IRasterRenderer; 5 6 IRaster pRaster = pRasterLayer.Raster; 7 IRasterBandCollection pRBandCol = pRaster as IRasterBandCollection; 8 IRasterBand pRBand = pRBandCol.Item(0); 9 10 if (pRBand.Histogram == null) //判断栅格是否计算直方图，没有的话要进行计算 11 { 12 pRBand.ComputeStatsAndHist(); 13 } 14 rasterRender.Raster = pRaster; 15 classifyRender.ClassCount = classCount; 16 17 for (int i = 0; i < classCount; i++) 18 { 19 if (i == 0) 20 { 21 classifyRender.set_Break(i, double.Parse("1")); 22 } 23 if (i == 1) 24 { 25 classifyRender.set_Break(i, double.Parse("251")); 26 } 27 if (i == 2) 28 { 29 classifyRender.set_Break(i, double.Parse("501")); 30 } 31 if (i == 3) 32 { 33 classifyRender.set_Break(i, double.Parse("751")); 34 } 35 if (i == 4) 36 { 37 classifyRender.set_Break(i, double.Parse("1001")); 38 } 39 if (i == 5) 40 { 41 classifyRender.set_Break(i, double.Parse("1251")); 42 } 43 if (i == 6) 44 { 45 classifyRender.set_Break(i, double.Parse("1501")); 46 } 47 if (i == 7) 48 { 49 classifyRender.set_Break(i, double.Parse("1751")); 50 } 51 if (i == 8) 52 { 53 classifyRender.set_Break(i, double.Parse("2001")); 54 } 55 if (i == 9) 56 { 57 classifyRender.set_Break(i, double.Parse("2251")); 58 } 59 } 60 61 rasterRender.Update(); 62 /* 63 IRgbColor pFromColor = new RgbColor() as IRgbColor; 64 pFromColor.Red = formColorRed; 65 pFromColor.Green = formColorGreen; 66 pFromColor.Blue = formColorBlue; 67 IRgbColor pToColor = new RgbColor() as IRgbColor; 68 pToColor.Red = toColorRed; 69 pToColor.Green = toColorGreen; 70 pToColor.Blue = toColorBlue; 71 */ 72 IAlgorithmicColorRamp colorRamp = new AlgorithmicColorRamp() as IAlgorithmicColorRamp; 73 colorRamp.Size = size; 74 //colorRamp.FromColor = pFromColor; 75 //colorRamp.ToColor = pToColor; 76 bool createColorRamp; 77 78 colorRamp.CreateRamp(out createColorRamp); 79 80 IFillSymbol fillSymbol = new SimpleFillSymbol() as IFillSymbol; 81 for (int i = 0; i < classifyRender.ClassCount; i++) 82 { 83 if(i == 0) 84 { 85 ESRI.ArcGIS.Display.IRgbColor tc = new ESRI.ArcGIS.Display.RgbColor(); 86 tc.Red = 255; 87 tc.Green = 255; 88 tc.Blue = 128; 89 fillSymbol.Color = tc as IColor; 90 classifyRender.set_Symbol(i, fillSymbol as ISymbol); 91 classifyRender.set_Label(i, classifyRender.get_Break(i).ToString("0") + "-" + "250"); //这里设置0是要整数显示 92 } 93 if (i == 1) 94 { 95 ESRI.ArcGIS.Display.IRgbColor tc = new ESRI.ArcGIS.Display.RgbColor(); 96 tc.Red = 128; 97 tc.Green = 255; 98 tc.Blue = 128; 99 fillSymbol.Color = tc as IColor; 100 classifyRender.set_Symbol(i, fillSymbol as ISymbol); 101 classifyRender.set_Label(i, classifyRender.get_Break(i).ToString("0") + "-" + "500"); //这里设置0是要整数显示 102 } 103 if (i == 2) 104 { 105 ESRI.ArcGIS.Display.IRgbColor tc = new ESRI.ArcGIS.Display.RgbColor(); 106 tc.Red = 128; 107 tc.Green = 255; 108 tc.Blue = 255; 109 fillSymbol.Color = tc as IColor; 110 classifyRender.set_Symbol(i, fillSymbol as ISymbol); 111 classifyRender.set_Label(i, classifyRender.get_Break(i).ToString("0") + "-" + "750"); //这里设置0是要整数显示 112 } 113 if (i == 3) 114 { 115 ESRI.ArcGIS.Display.IRgbColor tc = new ESRI.ArcGIS.Display.RgbColor(); 116 tc.Red = 0; 117 tc.Green = 128; 118 tc.Blue = 255; 119 fillSymbol.Color = tc as IColor; 120 classifyRender.set_Symbol(i, fillSymbol as ISymbol); 121 classifyRender.set_Label(i, classifyRender.get_Break(i).ToString("0") + "-" + "1000"); //这里设置0是要整数显示 122 } 123 if (i == 4) 124 { 125 ESRI.ArcGIS.Display.IRgbColor tc = new ESRI.ArcGIS.Display.RgbColor(); 126 tc.Red = 255; 127 tc.Green = 128; 128 tc.Blue = 192; 129 fillSymbol.Color = tc as IColor; 130 classifyRender.set_Symbol(i, fillSymbol as ISymbol); 131 classifyRender.set_Label(i, classifyRender.get_Break(i).ToString("0") + "-" + "1250"); //这里设置0是要整数显示 132 } 133 if (i == 5) 134 { 135 ESRI.ArcGIS.Display.IRgbColor tc = new ESRI.ArcGIS.Display.RgbColor(); 136 tc.Red = 255; 137 tc.Green = 0; 138 tc.Blue = 0; 139 fillSymbol.Color = tc as IColor; 140 classifyRender.set_Symbol(i, fillSymbol as ISymbol); 141 classifyRender.set_Label(i, classifyRender.get_Break(i).ToString("0") + "-" + "1500"); //这里设置0是要整数显示 142 } 143 if (i == 6) 144 { 145 ESRI.ArcGIS.Display.IRgbColor tc = new ESRI.ArcGIS.Display.RgbColor(); 146 tc.Red = 255; 147 tc.Green = 0; 148 tc.Blue = 255; 149 fillSymbol.Color = tc as IColor; 150 classifyRender.set_Symbol(i, fillSymbol as ISymbol); 151 classifyRender.set_Label(i, classifyRender.get_Break(i).ToString("0") + "-" + "1750"); //这里设置0是要整数显示 152 } 153 if (i == 7) 154 { 155 ESRI.ArcGIS.Display.IRgbColor tc = new ESRI.ArcGIS.Display.RgbColor(); 156 tc.Red = 255; 157 tc.Green = 128; 158 tc.Blue = 64; 159 fillSymbol.Color = tc as IColor; 160 classifyRender.set_Symbol(i, fillSymbol as ISymbol); 161 classifyRender.set_Label(i, classifyRender.get_Break(i).ToString("0") + "-" + "2000"); //这里设置0是要整数显示 162 } 163 if (i == 8) 164 { 165 ESRI.ArcGIS.Display.IRgbColor tc = new ESRI.ArcGIS.Display.RgbColor(); 166 tc.Red = 0; 167 tc.Green = 64; 168 tc.Blue = 128; 169 fillSymbol.Color = tc as IColor; 170 classifyRender.set_Symbol(i, fillSymbol as ISymbol); 171 classifyRender.set_Label(i, classifyRender.get_Break(i).ToString("0") + "-" + "2250"); //这里设置0是要整数显示 172 } 173 if (i == 9) 174 { 175 ESRI.ArcGIS.Display.IRgbColor tc = new ESRI.ArcGIS.Display.RgbColor(); 176 tc.Red = 255; 177 tc.Green = 255; 178 tc.Blue = 0; 179 fillSymbol.Color = tc as IColor; 180 classifyRender.set_Symbol(i, fillSymbol as ISymbol); 181 classifyRender.set_Label(i, classifyRender.get_Break(i).ToString("0") + "-" + "2500"); //这里设置0是要整数显示 182 } 183 } 184 pRasterLayer.Renderer = rasterRender; 185 //*********************************使栅格图层呈现透明效果******************************************* 186 //ILayerEffects pLayerEffects = pRasterLayer as ILayerEffects; 187 //pLayerEffects.Transparency = 50; 188 //************************************************************************************************* 189 190 191 this._mapControl.AddLayer(pRasterLayer); 192 this._mapControl.ActiveView.Refresh(); 193 }
（四）导出透明效果图片（PNG格式）
1 private void ExportMapByAbsPath(IActiveView activeView, string path) //导出透明效果图片 2 { 3 IExport export = new ExportPNGClass(); 4 IExportImage exportImg; 5 IExportPNG exportPNG; 6 int resolution = 96; 7 export.Resolution = resolution; 8 exportImg = export as IExportImage; 9 exportImg.ImageType = esriExportImageType.esriExportImageTypeTrueColor; //定义输出图片颜色模式为24位真彩色 10 exportPNG = export as IExportPNG; 11 12 //exportImg.BackgroundColor.RGB = exportPNG.TransparentColor.RGB; 13 ESRI.ArcGIS.Display.IRgbColor tc = new ESRI.ArcGIS.Display.RgbColor(); 14 tc.Red = 255; 15 tc.Green = 255; 16 tc.Blue = 0; 17 exportImg.BackgroundColor = tc as IColor; //设置输出图片的背景色 18 exportPNG.TransparentColor = tc as IColor; //设置输出图片的透明色 19 tagRECT exportRect = activeView.ExportFrame; 20 IEnvelope envelop = new EnvelopeClass(); 21 envelop.PutCoords(exportRect.left, exportRect.top, exportRect.right, exportRect.bottom); 22 export.PixelBounds = envelop; 23 export.ExportFileName = path; 24 int hDC = export.StartExporting(); 25 IEnvelope pVisbounds = null; 26 ITrackCancel ptrac = null; 27 //导出 28 activeView.Output(hDC, (int)export.Resolution, ref exportRect, pVisbounds, ptrac); 29 //结束导出 30 export.FinishExporting(); 31 //清理导出类 32 export.Cleanup(); 33 }
（五）调用上述方法
1 private void exportMapBtn_Click(object sender, EventArgs e) //实现了shp文件剪裁插值结果（栅格） 2 { 3 string filedName = "RES1_4M0_I"; 4 string pPath = System.Windows.Forms.Application.StartupPath + @"china_basic_map省会城市.shp"; 5 CreateRaster(filedName, pPath); 6 IRasterLayer pRasterLayer = this._mapControl.get_Layer(0) as RasterLayer; 7 IFeatureLayer featureLayer = this._mapControl.get_Layer(2) as IFeatureLayer; 8 IRaster raster = pRasterLayer.Raster; 9 IRaster resultRaster = ShpLayerClipRaster(featureLayer, raster); 10 IRasterLayer resultRasterLayer = new RasterLayer(); 11 resultRasterLayer.CreateFromRaster(resultRaster); 12 classifyColorToRaster(resultRasterLayer, 10, 10); 13 //***************************该删除方式有待改善************************************* 14 this._mapControl.DeleteLayer(1); 15 this._mapControl.DeleteLayer(1); 16 this._mapControl.DeleteLayer(1); 17 //********************************************************************************* 18 ExportMapByAbsPath(this._mapControl.ActiveView, "d:\abc.png"); //输出png格式图片 19 this._mapControl.DeleteLayer(0); 20 }
（五）目前任然存在的问题以及下一步的需求，后续有待解决
1.License偶尔报错（概率很小）
2.自定义色带时，初始值设置为0时，颜色渲染有问题，只要比0大便不会出现此问题
3.剪裁时需先调整范围，才能使剪裁范围最全面，效果最优
4.清理缓存，提高运行效率
5.Janus Form为试用版，最好要找到破解版
6.代码优化（组织思维、重构）
7.数据接入方式
8.定时出图（分钟级、小时级、日级、周级、月级、旬级、年级）