利用ARCENGINE生成等值线
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我想利用ARCENGINE生成等值线,在生成等值线前需要先生成表面(surface),利用IInterpolationOp.IDW方法生成表面,可是在这个地方怎么设置Z字段和网格单位大小啊,请教!
已成功,谢谢
'--------------------生成等值线--------------------------
Public Sub Contour()
Dim pInterpolationOp As IInterpolationOp
Set pInterpolationOp = New RasterInterpolationOp
' Create the input point object
Dim pInputDataset As IGeoDataset
Dim pFeatLayer As IFeatureLayer
' Calls function to open the point dataset from disk
Set pFeatLayer = basSub.FindLayerName(frmMain.MapControl1, "水准测量点")
Set pInputDataset = pFeatLayer
' Define the search radius
Dim pRadius As IRasterRadius
Set pRadius = New RasterRadius
pRadius.SetVariable 12
'Create FeatureClassDescriptor using a value field
Dim pFCDescriptor As IFeatureClassDescriptor
Set pFCDescriptor = New FeatureClassDescriptor
pFCDescriptor.Create pFeatLayer.FeatureClass, Nothing, "沉降量"
'Set cellsize for output raster in the environment
Dim dCellSize As Double
dCellSize = 200
Dim pEnv As IRasterAnalysisEnvironment
Set pEnv = pInterpolationOp
pEnv.SetCellSize esriRasterEnvValue, dCellSize
'Perform the interpolation
Dim pOutRaster As IRaster
Set pOutRaster = pInterpolationOp.IDW(pFCDescriptor, 2, pRadius)
'Add output into ArcMap as a raster layer
Dim pOutRasLayer As IRasterLayer
Set pOutRasLayer = New RasterLayer
pOutRasLayer.CreateFromRaster pOutRaster
frmMain.MapControl1.AddLayer pOutRasLayer
End Sub 本文介绍c#写的利用ArcGIS Engine生成等值线的方法。
c#写的根据雨量站的降雨量值内插出降雨量等值线的功能。做几点说明：
根据离散点生成等值线：
（1）判断等值线shapefile图层临时存放路径是否存在，如果不存在则创建，如果存在并不为空则删除重建；
（2）加【降雨量】字段并赋值，生成等值线后删除所加字段；
（3）根据所选的字段利用IDW内插生成raster，再设定间距生成contour并标注。
---------------------------------以下是源代码------------------------
private void button1_Click(object sender, EventArgs e)
{
//定义等值线临时shapefile图层存放路径
string ls_TempSavePath = @"C:\HNYTTEMP" ;
if (!Directory.Exists(ls_TempSavePath))//如果目录不存在，则创建
Directory.CreateDirectory(ls_TempSavePath);
DirectoryInfo di = new DirectoryInfo(ls_TempSavePath);
FileInfo[] fi = null;
fi = di.GetFiles();
if (fi.Length != 0)//如果目录不为空，则删除目录，然后重建
{
Directory.Delete(ls_TempSavePath, true);
Directory.CreateDirectory(ls_TempSavePath);
}
IMap pMap = axMapControl1.Map;
IInterpolationOp pInterpolationOp = new RasterInterpolationOpClass();
// Create the input point object
IGeoDataset pInputDataset ;
//雨量站图层【点】
IFeatureLayer pFeatLayer = axMapControl1.get_Layer(0) as IFeatureLayer;
// Calls function to open the point dataset from disk
IFeatureClass pFeatCla = pFeatLayer.FeatureClass;
IFeature pFeature ;
IField pField = new FieldClass();
IFieldEdit pFieldEdit = pField as IFieldEdit;
pFieldEdit .Name_2 = "降雨量"; pFieldEdit.Type_2 = esriFieldType.esriFieldTypeDouble;
pFieldEdit.Length_2 = 12;
pFieldEdit.IsNullable_2 = false;
pFieldEdit.DefaultValue_2 = 1111;
pFeatCla.AddField(pFieldEdit); //添加那个要用的字段进去
for(int ii=0;ii<pFeatCla.FeatureCount(null) - 1;ii++)
{
pFeature = pFeatCla.GetFeature(ii);
pFeature.set_Value(pFeature.Fields.FindField("降雨量"), 22+1999/(ii+2));
//要素字段赋值，这里是自己随便赋的值，仅做测试用
pFeature.Store();
}
pInputDataset = pFeatLayer as IGeoDataset;
// Define the search radius
IRasterRadius pRadius = new RasterRadiusClass();
object Missing = Type.Missing;
pRadius.SetVariable(12, ref Missing);
//Create FeatureClassDescriptor using a value field
IFeatureClassDescriptor pFCDescriptor = new FeatureClassDescriptorClass();
pFCDescriptor.Create( pFeatLayer.FeatureClass, null, "降雨量");
//Set cellsize for output raster in the environment
object cellSizeProvider = 20;
IRasterAnalysisEnvironment pEnv = pInterpolationOp as IRasterAnalysisEnvironment;
pEnv.SetCellSize(esriRasterEnvSettingEnum.esriRasterEnvValue, ref cellSizeProvider);
//Perform the interpolation
IRaster pOutRaster = pInterpolationOp.IDW(pFCDescriptor as IGeoDataset, 2, pRadius, ref Missing) as IRaster;
//Add output into ArcMap as a raster layer
RasterLayer pOutRasLayer = new RasterLayerClass();
