这个是父类

using GMap.NET.WindowsForms.ToolTips;

namespace GMap.NET.WindowsForms
{
using System;
using System.Drawing;
using System.Runtime.Serialization;
using System.Windows.Forms;

/// <summary>
/// GMap.NET marker
/// </summary>
[Serializable]
#if !PocketPC
public abstract class GMapMarker : ISerializable, IDisposable
#else
public class GMapMarker: IDisposable
#endif
{
#if PocketPC
static readonly System.Drawing.Imaging.ImageAttributes attr = new System.Drawing.Imaging.ImageAttributes();

static GMapMarker()
{
attr.SetColorKey(Color.White, Color.White);
}
#endif
GMapOverlay overlay;
public GMapOverlay Overlay
{
get
{
return overlay;
}
internal set
{
overlay = value;
}
}

private PointLatLng position;
public PointLatLng Position
{
get
{
return position;
}
set
{
if(position != value)
{
position = value;

if(IsVisible)
{
if(Overlay != null && Overlay.Control != null)
{
Overlay.Control.UpdateMarkerLocalPosition(this);
}
}
}
}
}

public object Tag;

Point offset;
public Point Offset
{
get
{
return offset;
}
set
{
if(offset != value)
{
offset = value;

if(IsVisible)
{
if(Overlay != null && Overlay.Control != null)
{
Overlay.Control.UpdateMarkerLocalPosition(this);
}
}
}
}
}

Rectangle area;

/// <summary>
/// marker position in local coordinates, internal only, do not set it manualy
/// </summary>
public Point LocalPosition
{
get
{
return area.Location;
}
set
{
if(area.Location != value)
{
area.Location = value;
{
if(Overlay != null && Overlay.Control != null)
{
if(!Overlay.Control.HoldInvalidation)
{
Overlay.Control.Core.Refresh.Set();
}
}
}
}
}
}

/// <summary>
/// ToolTip position in local coordinates
/// </summary>
public Point ToolTipPosition
{
get
{
Point ret = area.Location;
ret.Offset(-Offset.X, -Offset.Y);
return ret;
}
}

public Size Size
{
get
{
return area.Size;
}
set
{
area.Size = value;
}
}

public Rectangle LocalArea
{
get
{
return area;
}
}

internal Rectangle LocalAreaInControlSpace
{
get
{
Rectangle r = area;
if(Overlay != null && Overlay.Control != null)
{
r.Offset((int)Overlay.Control.Core.renderOffset.X, (int)overlay.Control.Core.renderOffset.Y);
}
return r;
}
}

public GMapToolTip ToolTip;

public MarkerTooltipMode ToolTipMode = MarkerTooltipMode.OnMouseOver;

string toolTipText;
public string ToolTipText
{
get
{
return toolTipText;
}

set
{
if(ToolTip == null)
{
#if !PocketPC
ToolTip = new GMapRoundedToolTip(this);
#else
ToolTip = new GMapToolTip(this);
#endif
}
toolTipText = value;
}
}

private bool visible = true;

/// <summary>
/// is marker visible
/// </summary>
public bool IsVisible
{
get
{
return visible;
}
set
{
if(value != visible)
{
visible = value;

if(Overlay != null && Overlay.Control != null)
{
if(visible)
{
Overlay.Control.UpdateMarkerLocalPosition(this);
}

{
if(!Overlay.Control.HoldInvalidation)
{
Overlay.Control.Core.Refresh.Set();
}
}
}
}
}
}

/// <summary>
/// if true, marker will be rendered even if it's outside current view
/// </summary>
public bool DisableRegionCheck = false;

/// <summary>
/// can maker receive input
/// </summary>
public bool IsHitTestVisible = true;

private bool isMouseOver = false;

/// <summary>
/// is mouse over marker
/// </summary>
public bool IsMouseOver
{
get
{
return isMouseOver;
}
internal set
{
isMouseOver = value;
}
}

public GMapMarker(PointLatLng pos)
{
this.Position = pos;
}

public virtual void OnRender(Graphics g)
{
//
}

#if PocketPC
protected void DrawImageUnscaled(Graphics g, Bitmap inBmp, int x, int y)
{
g.DrawImage(inBmp, new Rectangle(x, y, inBmp.Width, inBmp.Height), 0, 0, inBmp.Width, inBmp.Height, GraphicsUnit.Pixel, attr);
}
#endif

#if !PocketPC
#region ISerializable Members

/// <summary>
/// Populates a <see cref="T:System.Runtime.Serialization.SerializationInfo"/> with the data needed to serialize the target object.
/// </summary>
/// <param name="info">The <see cref="T:System.Runtime.Serialization.SerializationInfo"/> to populate with data.</param>
/// <param name="context">The destination (see <see cref="T:System.Runtime.Serialization.StreamingContext"/>) for this serialization.</param>
/// <exception cref="T:System.Security.SecurityException">
/// The caller does not have the required permission.
/// </exception>
public void GetObjectData(SerializationInfo info, StreamingContext context)
{
info.AddValue("Position", this.Position);
info.AddValue("Tag", this.Tag);
info.AddValue("Offset", this.Offset);
info.AddValue("Area", this.area);
info.AddValue("ToolTip", this.ToolTip);
info.AddValue("ToolTipMode", this.ToolTipMode);
info.AddValue("ToolTipText", this.ToolTipText);
info.AddValue("Visible", this.IsVisible);
info.AddValue("DisableregionCheck", this.DisableRegionCheck);
info.AddValue("IsHitTestVisible", this.IsHitTestVisible);
}

/// <summary>
/// Initializes a new instance of the <see cref="GMapMarker"/> class.
/// </summary>
/// <param name="info">The info.</param>
/// <param name="context">The context.</param>
protected GMapMarker(SerializationInfo info, StreamingContext context)
{
this.Position = Extensions.GetStruct<PointLatLng>(info, "Position", PointLatLng.Empty);
this.Tag = Extensions.GetValue<object>(info, "Tag", null);
this.Offset = Extensions.GetStruct<Point>(info, "Offset", Point.Empty);
this.area = Extensions.GetStruct<Rectangle>(info, "Area", Rectangle.Empty);
this.ToolTip = Extensions.GetValue<GMapToolTip>(info, "ToolTip", null);
this.ToolTipMode = Extensions.GetStruct<MarkerTooltipMode>(info, "ToolTipMode", MarkerTooltipMode.OnMouseOver);
this.ToolTipText = info.GetString("ToolTipText");
this.IsVisible = info.GetBoolean("Visible");
this.DisableRegionCheck = info.GetBoolean("DisableregionCheck");
this.IsHitTestVisible = info.GetBoolean("IsHitTestVisible");
}

#endregion
#endif

#region IDisposable Members

bool disposed = false;

public virtual void Dispose()
{
if(!disposed)
{
disposed = true;

Tag = null;

if(ToolTip != null)
{
toolTipText = null;
ToolTip.Dispose();
ToolTip = null;
}
}
}

#endregion
}

public delegate void MarkerClick(GMapMarker item, MouseEventArgs e);
public delegate void MarkerEnter(GMapMarker item);
public delegate void MarkerLeave(GMapMarker item);

/// <summary>
/// modeof tooltip
/// </summary>
public enum MarkerTooltipMode
{
OnMouseOver,
Never,
Always,
}
}