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自定义Marker，可以理解为在地图上自定义图标（Custom Marker），先看看GMap的地图和图标的显示方式：
Map控件上可以添加Overlay（图层），可以添加多个图层，先添加的图层在下面显示。
图层上可以添加GMapMarker，当然也可以添加GMapPolygon和GMapRoute，后续介绍。
在地图的使用中常要求的功能就是添加自定义图标，可以点击图标、删除图标、拖动图标、高亮图标等。
下面介绍这些功能的实现（主要是基于WinForm的，WPF的可以参考官方Demo实现）：
1、自定义图标，使用官方的Marker：
Bitmap bitmap = Bitmap.FromFile("F:\\Projects\\GMapDemo\\GMapDemo\\Image\\A.png") as Bitmap; GMapMarker marker = new GMarkerGoogle(point, bitmap);
直接使用GMap.NET.WindowsForms.Markers中的GMarkerGoogle，传入一个Bitmap，就可以使用自定义的图片来做图标。
2、继承GMapMarker，自定义Marker：
using System; using System.Collections.Generic; using System.Linq; using System.Text; using GMap.NET; using GMap.NET.WindowsForms; using System.Drawing; namespace GMapWinFormDemo { class GMapMarkerImage : GMapMarker { private Image image; public Image Image { get { return image; } set { image = value; if (image != null) { this.Size = new Size(image.Width, image.Height); } } } public Pen Pen { get; set; } public Pen OutPen { get; set; } public GMapMarkerImage(GMap.NET.PointLatLng p, Image image) : base(p) { Size = new System.Drawing.Size(image.Width, image.Height); Offset = new System.Drawing.Point(-Size.Width / 2, -Size.Height / 2); this.image = image; Pen = null; OutPen = null; } public override void OnRender(Graphics g) { if (image == null) return; Rectangle rect = new Rectangle(LocalPosition.X, LocalPosition.Y, Size.Width, Size.Height); g.DrawImage(image, rect); if (Pen != null) { g.DrawRectangle(Pen, rect); } if (OutPen != null) { g.DrawEllipse(OutPen, rect); } } public override void Dispose() { if (Pen != null) { Pen.Dispose(); Pen = null; } if (OutPen != null) { OutPen.Dispose(); OutPen = null; } base.Dispose(); } } }
介绍下GMapMarkerImage三个属性的作用：
Image：保存图标的图片。
Pen：在图片外围画DrawRectangle的Pen，当其不为null的时候，会在图片的外围画一个矩形，实现高亮（highlight）的效果。
OutPen：在图片外围画DrawEllipse的Pen，当其不为null的时候，会在图片外围画一个一个椭圆，设置这个值可以实现闪动。
3、移动图标（Move Marker）的实现：
在MapControl中添加如下事件的响应：
mapControl.MouseDown += new MouseEventHandler(mapControl_MouseDown); mapControl.MouseUp += new MouseEventHandler(mapControl_MouseUp); mapControl.MouseMove += new MouseEventHandler(mapControl_MouseMove); mapControl.OnMarkerClick += new MarkerClick(mapControl_OnMarkerClick); mapControl.OnMarkerEnter += new MarkerEnter(mapControl_OnMarkerEnter); mapControl.OnMarkerLeave += new MarkerLeave(mapControl_OnMarkerLeave);
MouseDown和MouseUp中判断左键是否按下（用左键来移动图标）。
OnMarkerEnter中设置选中的Marker，同时设置Pen的值，实现高亮。
OnMarkerLeave中取消选中的Marker，取消Pen的值，取消高亮。
MouseMove中更新选中选中Marker的Position就可以了。
4、图标闪动的实现：
需要一个定时器：使用的是Form下的Timer，定时器响应的事件：
void blinkTimer_Tick(object sender, EventArgs e) { foreach (GMapMarker m in objects.Markers) { if (m is GMapMarkerImage) { GMapMarkerImage marker = m as GMapMarkerImage; if (marker.OutPen == null) marker.OutPen = new Pen(Brushes.Red, 2); else { marker.OutPen.Dispose(); marker.OutPen = null; } } } mapControl.Refresh(); }
更新所有Marker的OutPen的值（当然你也可以只更新某个Marker），通过在图标上画圈圈来实现闪动，当然你也可以通过设置Marker的IsVisible属性来实现自己想要的效果。。。
效果图如下：
全部代码如下：
using System; using System.Collections.Generic; using System.ComponentModel; using System.Data; using System.Drawing; using System.Linq; using System.Text; using System.Windows.Forms; using GMap.NET; using GMap.NET.WindowsForms; using GMap.NET.MapProviders; using GMap.NET.WindowsForms.Markers; namespace GMapWinFormDemo { public partial class MainForm : Form { private GMapOverlay objects = new GMapOverlay("objects"); //放置marker的图层 private GMapMarkerImage currentMarker; private bool isLeftButtonDown = false; private Timer blinkTimer = new Timer(); public MainForm() { InitializeComponent(); try { System.Net.IPHostEntry e = System.Net.Dns.GetHostEntry("ditu.google.cn"); } catch { mapControl.Manager.Mode = AccessMode.CacheOnly; MessageBox.Show("No internet connection avaible, going to CacheOnly mode.", "GMap.NET Demo", MessageBoxButtons.OK, MessageBoxIcon.Warning); } mapControl.CacheLocation = Environment.CurrentDirectory + "\\GMapCache\\"; //缓存位置 mapControl.MapProvider = GMapProviders.GoogleChinaMap; //google china 地图 mapControl.MinZoom = 2; //最小比例 mapControl.MaxZoom = 17; //最大比例 mapControl.Zoom = 5; //当前比例 mapControl.ShowCenter = false; //不显示中心十字点 mapControl.DragButton = System.Windows.Forms.MouseButtons.Left; //左键拖拽地图 mapControl.Position = new PointLatLng(32.064,118.704); //地图中心位置：南京 mapControl.OnMapZoomChanged += new MapZoomChanged(mapControl_OnMapZoomChanged); mapControl.MouseClick += new MouseEventHandler(mapControl_MouseClick); mapControl.MouseDown += new MouseEventHandler(mapControl_MouseDown); mapControl.MouseUp += new MouseEventHandler(mapControl_MouseUp); mapControl.MouseMove += new MouseEventHandler(mapControl_MouseMove); mapControl.OnMarkerClick += new MarkerClick(mapControl_OnMarkerClick); mapControl.OnMarkerEnter += new MarkerEnter(mapControl_OnMarkerEnter); mapControl.OnMarkerLeave += new MarkerLeave(mapControl_OnMarkerLeave); mapControl.Overlays.Add(objects); } void mapControl_MouseMove(object sender, MouseEventArgs e) { if (e.Button == System.Windows.Forms.MouseButtons.Left && isLeftButtonDown) { if (currentMarker != null) { PointLatLng point = mapControl.FromLocalToLatLng(e.X, e.Y); currentMarker.Position = point; currentMarker.ToolTipText = string.Format("{0},{1}", point.Lat, point.Lng); } } } void mapControl_MouseUp(object sender, MouseEventArgs e) { if (e.Button == System.Windows.Forms.MouseButtons.Left) { isLeftButtonDown = false; } } void mapControl_MouseDown(object sender, MouseEventArgs e) { if (e.Button == System.Windows.Forms.MouseButtons.Left) { isLeftButtonDown = true; } } void mapControl_OnMarkerLeave(GMapMarker item) { if (item is GMapMarkerImage) { currentMarker = null; GMapMarkerImage m = item as GMapMarkerImage; m.Pen.Dispose(); m.Pen = null; } } void mapControl_OnMarkerEnter(GMapMarker item) { if (item is GMapMarkerImage) { currentMarker = item as GMapMarkerImage; currentMarker.Pen = new Pen(Brushes.Red, 2); } } void mapControl_OnMarkerClick(GMapMarker item, MouseEventArgs e) { } void mapControl_MouseClick(object sender, MouseEventArgs e) { if(e.Button == System.Windows.Forms.MouseButtons.Right) { //objects.Markers.Clear(); PointLatLng point = mapControl.FromLocalToLatLng(e.X,e.Y); //GMapMarker marker = new GMarkerGoogle(point, GMarkerGoogleType.green); Bitmap bitmap = Bitmap.FromFile("F:\\Projects\\GMapDemo\\GMapDemo\\Image\\A.png") as Bitmap; //GMapMarker marker = new GMarkerGoogle(point, bitmap); GMapMarker marker = new GMapMarkerImage(point, bitmap); marker.ToolTipMode = MarkerTooltipMode.OnMouseOver; marker.ToolTipText = string.Format("{0},{1}", point.Lat, point.Lng); objects.Markers.Add(marker); } } void mapControl_OnMapZoomChanged() { } private void buttonBeginBlink_Click(object sender, EventArgs e) { blinkTimer.Interval = 1000; blinkTimer.Tick += new EventHandler(blinkTimer_Tick); blinkTimer.Start(); } void blinkTimer_Tick(object sender, EventArgs e) { foreach (GMapMarker m in objects.Markers) { if (m is GMapMarkerImage) { GMapMarkerImage marker = m as GMapMarkerImage; if (marker.OutPen == null) marker.OutPen = new Pen(Brushes.Red, 2); else { marker.OutPen.Dispose(); marker.OutPen = null; } } } mapControl.Refresh(); } private void buttonStopBlink_Click(object sender, EventArgs e) { blinkTimer.Stop(); foreach (GMapMarker m in objects.Markers) { if (m is GMapMarkerImage) { GMapMarkerImage marker = m as GMapMarkerImage; marker.OutPen.Dispose(); marker.OutPen = null; } } mapControl.Refresh(); } } }
引自：http://www.cnblogs.com/luxiaoxun/p/3475355.html
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原文地址：http://www.cnblogs.com/xinzheng/p/5416780.html
