距离测量

实现在IMapcontrol上采点，双击结束采点进行距离测量，并标注在IMapcontrol上，实现结果如下：

1. 初始化主要变量：

        private bool m_bStart = false;
        private INewLineFeedback m_pNewLineFeedback = null;
        private IPoint m_prevPoint = null;
        private double m_CurDistance = 0.0;
        private double m_TotalDistance = 0.0;

2.MouseDown事件：

IPoint pt = m_pMapControl.ToMapPoint(X, Y);

            if (m_bStart && m_pNewLineFeedback != null)
            {
                m_pNewLineFeedback.AddPoint(pt);
                              if (m_prevPoint != null)
                {
                    m_CurDistance = ReturnDistance(m_prevPoint, pt);
                    m_TotalDistance += m_CurDistance;
                    m_prevPoint = pt;
                }
            }
            else
            {
                m_pNewLineFeedback.Display = m_pMapControl.ActiveView.ScreenDisplay;
                m_bStart = true;
                m_pNewLineFeedback.Start(pt);
                m_prevPoint = pt;
             }

3.MouseDoubleClick事件：

try
            {
                IPolyline pline = m_pNewLineFeedback.Stop();
                IGraphicsContainer pGraphicsContainer = m_pMapControl.ActiveView as IGraphicsContainer;
                
                DrawElement(pline, pGraphicsContainer);
            }
            catch (Exception ex)
            {
                System.Windows.Forms.MessageBox.Show(ex.ToString(), "提示");

            }
            m_TotalDistance = 0;
            m_bStart = false;

4.在Mapcontrol上添加标注：

添加所画线的标注：

1             IRgbColor pColor = new RgbColorClass();
 2             ILineElement pLineElement = new LineElementClass();
 3             IElement pElement = pLineElement as IElement;
 4             pElement.Geometry = pLine as IGeometry;
 5 
 6             ISimpleLineSymbol pSmplLine = new SimpleLineSymbolClass();
 7             pColor = new RgbColorClass();
 8             pColor.Red = 0; pColor.Blue = 250; pColor.Green = 0;
 9             pSmplLine.Color = pColor as IColor;
10             pSmplLine.Style = esriSimpleLineStyle.esriSLSSolid;
11             pSmplLine.Width = 1;
12             pLineElement.Symbol = pSmplLine as ILineSymbol;
13 
14             pGraphicsContainer.AddElement(pElement, 0);

添加文字标注：

           ITextElement pTextElement = new TextElementClass();
            pElement = pTextElement as IElement;
            pElement.Geometry = pLine as IGeometry;
            ISimpleTextSymbol pSimpleTextSymbol = new TextSymbolClass();
            
            pColor.Red = 255; pColor.Green = 0; pColor.Blue = 0;
            pSimpleTextSymbol.Color = pColor as IColor;
            stdole.IFont font = new stdole.StdFontClass();
            font.Name = "宋体";
            font.Bold = false;
            font.Size = 18;
            pSimpleTextSymbol.Font = font as IFontDisp;

            pTextElement.Symbol = (ITextSymbol)pSimpleTextSymbol;
            pTextElement.ScaleText = false;
            pTextElement.Text = "距离：" + pLine.Length.ToString("0.00") + " 米";          
            pGraphicsContainer.AddElement(pElement, 0);       

刷新显示：

m_pMapControl.ActiveView.PartialRefresh(esriViewDrawPhase.esriViewGraphics, null, null);

另：返回两个IGeometry之间的距离：

private double ReturnDistance(IPoint point1, IPoint point2)
        {
            IProximityOperator pPO = point1 as IProximityOperator;
            double dis = pPO.ReturnDistance(point2);
            return dis;           
        }