(转载)基于ArcGIS Engine编写的ColorRamp对栅格渲染代码

转载于：http://www.gisall.com/html/59/26859-2432.html

需要实现类似ArcMap中的单击TOC控件来对图层进行渲染，示例代码中主要针对的是矢量图层FeatureLayerClass, 没有针对RasterLayerClass, 不过原理是很类似的，我们都知道对栅格渲染主要有三种方式：

1.Raster Unique value Renderer  唯一值渲染

2.Raster Classify Renderer  分类渲染

3.Raster Stretch Renderer   色带渲染

 

而现在要实现ColorRamp 色带的渲染：

 

原理主要就是 利用一个axSymbolControl来承载AE中的ColorRamp枚举值，然后主程序TOC控件调用选中的Style. Item 样式并赋值给IRasterStretchColorRampRenderer的对象实例。

 

关键源代码是：

1. 在ColorSymbolForm的载入初始化时，添加ESRI中包含ColorRamp的样式：

//Get the ArcGIS install location
 string sInstall = routin_ReadRegistry("SOFTWARE\\ESRI\\CoreRuntime");
 //Load the ESRI.ServerStyle. file into the SymbologyControl 
axSymbologyControl1.LoadStyleFile(sInstall + "\\Styles\\ESRI.ServerStyle");

2.选中其中的一个样式

public IStyleGalleryItem GetItem(ESRI.ArcGIS.Controls.esriSymbologyStyleClass styleClass)
 { m_StyleGalleryItem = null;
 //Disable ok button
 button1.Enabled = false;
 //Set the style. class
 axSymbologyControl1.StyleClass = styleClass; 
//Unselect any selected item in the current style. class
 axSymbologyControl1.GetStyleClass(styleClass).UnselectItem(); 
//Show the modal form. this.ShowDialog();
 //Return the selected label style.
 return m_StyleGalleryItem;
 } 

3. 选中样式时相应的事件

private void axSymbologyControl1_OnItemSelected(object sender, ESRI.ArcGIS.Controls.ISymbologyControlEvents_OnItemSelectedEvent e)
 { //Get the selected item
 m_StyleGalleryItem = axSymbologyControl1.GetStyleClass(axSymbologyControl1.StyleClass).GetSelectedItem();
 //Enable ok button
 button1.Enabled = true; 
}

 

4.然后在主程序中添加TOC右击事件，用Stretch Renderer  色带渲染：

private void axTOCControl_Temp_OnMouseDown(object sender, ITOCControlEvents_OnMouseDownEvent e) 
{ if (e.button != 2) return;
 IBasicMap map = new MapClass(); 
ILayer layer = new RasterLayerClass(); 

object ther = new object(); 

object index = new object();
 esriTOCControlItem item = new esriTOCControlItem();
 //Determine what kind of item has been clicked on
 this.axTOCControl_Temp.HitTest(e.x, e.y, ref item, ref map, ref layer, ref other, ref index); 
if (layer == null) return; 
IRasterLayer rasterLayer = layer as IRasterLayer; 
if (rasterLayer == null) return; 
IRasterStretchColorRampRenderer pStretchColorRasterRenderer = new RasterStretchColorRampRendererClass();
 IRasterRenderer pRasterRenderer = pStretchColorRasterRenderer as IRasterRenderer; 
pRasterRenderer.Raster = rasterLayer.Raster; pRasterRenderer.Update();
 //Get the IStyleGalleryItem IStyleGalleryItem styleGalleryItem = null;
 //Create the form. with the SymbologyControl ColorSymbolForm. symbolForm. = new ColorSymbolForm();
 //Get teh symbol item styleGalleryItem = symbolForm.GetItem(esriSymbologyStyleClass.esriStyleClassColorRamps);
 //Release the form. symbolForm.Dispose(); this.Focus();
 if (styleGalleryItem == null) return;
 IColorRamp colorRamp = (IColorRamp)styleGalleryItem.Item;
 pStretchColorRasterRenderer.BandIndex = 0; pStretchColorRasterRenderer.ColorRamp = colorRamp as IColorRamp;
 pRasterRenderer.Update(); 
rasterLayer.Renderer = pStretchColorRasterRenderer as IRasterRenderer; 
this.axMapControl_Temp.ActiveView.PartialRefresh(esriViewDrawPhase.esriViewGeography, null, null);
 this. axMapControl_Temp.SetBuddyControl(axMapControl_Temp); this.axTOCControl_Temp.Refresh(); 
}