地图 唯一值渲染

 

/// <summary>
        /// 唯一值渲染
        /// </summary>
        /// <param name="pFeaturelayer">渲染图层</param>
        /// <param name="sRenderField">渲染字段</param>
        /// <param name="pQueryFilter">渲染过滤器</param>
        public static IUniqueValueRenderer FunUniqueValueRender(IFeatureLayer pFeaturelayer, string sRenderField, IQueryFilter pQueryFilter)
        {
            try
            {
                IFeatureClass pFeatureClass = null;
                IRandomColorRamp pRandomColorRamp = null;
                IUniqueValueRenderer pUniqueValueRenderer = null;
                IFeatureCursor pFeatureCursor = null;
                int iRenderFiledIndex;
                int iCount;

                if (pQueryFilter == null)
                    pQueryFilter = new QueryFilterClass();

                //获取渲染字段
                pFeatureClass = pFeaturelayer.FeatureClass;
                iRenderFiledIndex = FunGetFiledIndexByName(pFeatureClass, sRenderField);//返回渲染字段所在的索引值
                if (iRenderFiledIndex == -1)
                {
                    MessageBox.Show("字段索引读取错误");
                    return null;
                }

                //获取渲染字段的唯一值个数
                iCount = pFeatureClass.FeatureCount(pQueryFilter);
                if (iCount < 1)
                {
                    MessageBox.Show("计算字段唯一值个数发生错误");
                    return null;
                }
                //创建并得到IRandomColorRamp 
                pRandomColorRamp = new RandomColorRampClass();

                pRandomColorRamp.StartHue = 0;
                pRandomColorRamp.MinValue = 99;
                pRandomColorRamp.MinSaturation = 15;
                pRandomColorRamp.EndHue = 360;
                pRandomColorRamp.MaxValue = 100;
                pRandomColorRamp.MaxSaturation = 30;
                pRandomColorRamp.Size = iCount;
                bool ok;
                pRandomColorRamp.CreateRamp(out ok);


                //设置UniqueValueRenderer
                pUniqueValueRenderer = new UniqueValueRendererClass();
                pUniqueValueRenderer.FieldCount = 1;
                pUniqueValueRenderer.set_Field(0, sRenderField);

                //遍历所有要素,并添加渲染值
                pFeatureCursor = pFeatureClass.Search(pQueryFilter, true);
                IEnumColors pEnumColors = pRandomColorRamp.Colors;
                pEnumColors.Reset();
                IColor pColor;
                IFeature pFeature;
                string sValue;
                for (int index = 0; index < iCount; index++)
                {
                    pColor = pEnumColors.Next();
                    pFeature = pFeatureCursor.NextFeature();
                    sValue = Convert.ToString(pFeature.get_Value(iRenderFiledIndex));
                    bool isHad = false;
                    for (int i = 0; i < pUniqueValueRenderer.ValueCount; i++)
                    {
                        if (sValue == pUniqueValueRenderer.get_Value(i).ToString())
                        {
                            isHad = true;
                            break;
                        }
                    }
                    if (!isHad)
                    {
                        if (pFeatureClass.ShapeType == esriGeometryType.esriGeometryPolygon)
                        {
                            ISimpleFillSymbol pSimpleFillSymbol = new SimpleFillSymbolClass();
                            pSimpleFillSymbol.Style = esriSimpleFillStyle.esriSFSSolid;
                            pSimpleFillSymbol.Color = pColor;
                            pUniqueValueRenderer.AddValue(sValue, sValue, (ISymbol)pSimpleFillSymbol);
                        }
                        else if (pFeatureClass.ShapeType == esriGeometryType.esriGeometryPoint)
                        {
                            ISimpleMarkerSymbol pSimpleMarkerSymbol = new SimpleMarkerSymbolClass();
                            pSimpleMarkerSymbol.Style = esriSimpleMarkerStyle.esriSMSCircle;
                            pSimpleMarkerSymbol.Color = pColor;
                            pSimpleMarkerSymbol.Size = 6;
                            pUniqueValueRenderer.AddValue(sValue, sValue, (ISymbol)pSimpleMarkerSymbol);
                        }
                    }
                }

                //释放变量
                pFeatureCursor = null;
                pRandomColorRamp = null;
                pFeatureClass = null;

                return pUniqueValueRenderer;

            }
            catch (Exception ex)
            {
                MessageBox.Show(ex.Message);
                return null;
            }
        }