用C#和ArcGIS Engine实现在地图上绘制形状

版权声明：本文为博主原创文章，不需博主允许即可随意转载。 https://blog.csdn.net/a_dev/article/details/83302221

初始化时将地图控件MapControl传进来，绘制过程中监听鼠标操作事件，适情况隐藏父级窗体，绘制点、多段线、多边形、圆形、矩形等。

    public class DrawGeometryHelper
    {
        private IMapControl2 m_pMapControl;
        private IntPtr m_hWnd;

        public DrawGeometryHelper()
        {

        }

        public DrawGeometryHelper(IMapControl2 mapControl, IntPtr? hWnd)
        {
            Init(mapControl, hWnd);
        }

        public void Init(IMapControl2 mapControl, IntPtr? hWnd)
        {
            m_pMapControl = mapControl;
            if (hWnd != null)
            {
                m_hWnd = (IntPtr)hWnd;
            }
        }


        private POINT GetMouseDownPoint(int hWnd = 0)
        {
            POINT pt = new POINT();
            while (true)
            {
                bool b = false;
                var msg = new MSG();
                while (PeekMessage(ref msg, hWnd, 0x201, 0x203, PeekMessageOption.PM_REMOVE))
                {
                    if (msg.Message == 0x201)
                    {
                        if (GetCursorPos(out pt) && pt.X > 0 && pt.Y > 0)
                        {
                            b = true;
                            break;
                        }
                    }
                    TranslateMessage(ref msg);
                    DispatchMessage(ref msg);
                }
                if (b)
                    break;
            }
            return pt;
        }


        public IGeometry Draw(DrawTypeEnum drawType = DrawTypeEnum.Polygon, double buffer = 0.0, bool hideWindow = true)
        {
            if (null == m_pMapControl) return null;

            var bHide = false;
            if (hideWindow && null != m_hWnd)
            {
                bHide = Win32ApiFormProc.ShowWindow(m_hWnd, Win32ApiFormProc.SW_HIDE);
            }

            var originalTool = m_pMapControl.CurrentTool;
            var originalMoustPointer = m_pMapControl.MousePointer;

            m_pMapControl.CurrentTool = null;
            m_pMapControl.MousePointer = esriControlsMousePointer.esriPointerPencil;

            var point = GetMouseDownPoint();

            IGeometry pGeometry = null;

            switch (drawType)
            {
                case DrawTypeEnum.Point:
                    {
                        pGeometry = m_pMapControl.ToMapPoint(point.X, point.Y);
                        break;
                    }
                case DrawTypeEnum.Polyline:
                    {
                        pGeometry = m_pMapControl.TrackLine();
                        break;
                    }
                case DrawTypeEnum.Polygon:
                    {
                        pGeometry = m_pMapControl.TrackPolygon();
                        break;
                    }
                case DrawTypeEnum.Rectangle:
                    {
                        pGeometry = m_pMapControl.TrackRectangle();
                        break;
                    }
                case DrawTypeEnum.Circle:
                    {
                        pGeometry = m_pMapControl.TrackCircle();
                        break;
                    }
                default:
                    break;
            }
            m_pMapControl.CurrentTool = originalTool;
            m_pMapControl.MousePointer = originalMoustPointer;
            if (null != pGeometry)
            {
                m_pMapControl.FlashShape(pGeometry);
            }

            if (bHide)
            {
                Win32ApiFormProc.ShowWindow(m_hWnd, Win32ApiFormProc.SW_SHOW);
            }
            return pGeometry;
        }
    }

其中，ShowWindow方法为从user32.dll中导入：

        [DllImport("user32.dll", EntryPoint = "ShowWindow")]
        public static extern bool ShowWindow(IntPtr hwnd, int nCmdShow);

绘制类型枚举如下：

public enum DrawTypeEnum
{
    Point = 0,
    Polyline = 1,
    Polygon = 2,
    Rectangle = 3,
    Circle = 4
}