Winform下的地图开发控件(GMap.NET)使用心得之二

在上篇《Winform下的地图开发控件(GMap.NET)使用心得》中简单介绍了GMap.NET的控件基本情况，本篇开始介绍一下相关的代码操作。

其实目前GMap.NET提供的功能还不是很多，因此其演示的例子基本上都涉及到了，我在此基础上做了一些改进和运用，总结下功能代码吧。

首先使用控件前，需要初始化一些变量和事件，初始化代码如下所示：

代码

         private   void  InitMapControl()
        {
             this .gMapControl1.Manager.Mode  =  AccessMode.ServerAndCache;
             this .gMapControl1.MapType  =  MapType.GoogleMapChina;
             this .gMapControl1.MaxZoom  =   18 ;
             this .gMapControl1.MinZoom  =   8 ;
             this .gMapControl1.Zoom  =   13 ;

             this .gMapControl1.MouseMove  +=   new  MouseEventHandler(gMapControl1_MouseMove);
             this .gMapControl1.DoubleClick  +=   new  EventHandler(gMapControl1_DoubleClick);
             this .gMapControl1.MouseDown  +=   new  MouseEventHandler( this .MainMap_MouseDown);
             this .gMapControl1.MouseUp  +=   new  MouseEventHandler( this .MainMap_MouseUp);

             this .gMapControl1.OnCurrentPositionChanged  +=   new  CurrentPositionChanged( this .MainMap_OnCurrentPositionChanged);
             this .gMapControl1.OnTileLoadStart  +=   new  TileLoadStart( this .MainMap_OnTileLoadStart);
             this .gMapControl1.OnTileLoadComplete  +=   new  TileLoadComplete( this .MainMap_OnTileLoadComplete);

             this .gMapControl1.OnMarkerClick  +=   new  MarkerClick( this .MainMap_OnMarkerClick);
             this .gMapControl1.OnMapZoomChanged  +=   new  MapZoomChanged( this .MainMap_OnMapZoomChanged);
             this .gMapControl1.OnMapTypeChanged  +=   new  MapTypeChanged( this .MainMap_OnMapTypeChanged);

             this .routes  =   new  GMapOverlay( this .gMapControl1,  " routes " );
             this .gMapControl1.Overlays.Add( this .routes);
             this .objects  =   new  GMapOverlay( this .gMapControl1,  " objects " );
             this .gMapControl1.Overlays.Add( this .objects);
             this .top  =   new  GMapOverlay( this .gMapControl1,  " top " );
             this .gMapControl1.Overlays.Add( this .top);
             this .currentMarker  =   new  GMapMarkerGoogleRed( this .gMapControl1.CurrentPosition);
             this .top.Markers.Add( this .currentMarker);
             this .center  =   new  GMapMarkerCross( this .gMapControl1.CurrentPosition);
             this .top.Markers.Add( this .center);

             this .myShop  =   new  GMapOverlay( this .gMapControl1,  " myShop " );
             this .gMapControl1.Overlays.Add( this .myShop);
            DisplayMyShop();
            
            SetZoomCenter();

             this .gMapControl1.DragButton  =  MouseButtons.Left;
        }

 

 

其中的OnMarkerClick好像虽然有相关的事件，但是并不能捕获单击图标的时间操作，估计是没有完成该功能吧。

GMap.NET提供了各种鼠标的操作事件，我们重载即可实现特殊的控制处理了：

鼠标事件操作

         void  gMapControl1_DoubleClick( object  sender, EventArgs e)
        {
             this .gMapControl1.Zoom  +=   1 ;
             this .gMapControl1.CurrentPosition  =  lastPosition;
        }

         void  gMapControl1_MouseMove( object  sender, MouseEventArgs e)
        {
            PointLatLng latLng  =   this .gMapControl1.FromLocalToLatLng(e.X, e.Y);
             this .tsslPosition.Text  =   string .Format( " 经度：{0}, 纬度：{1}  " , latLng.Lng, latLng.Lat);
        }

         private   void  MainMap_MouseDown( object  sender, MouseEventArgs e)
        {
             if  (e.Button  ==  MouseButtons.Left)
            {
                 this .isMouseDown  =   true ;
                lastPosition  =   this .gMapControl1.FromLocalToLatLng(e.X, e.Y);              
            }            
        }

         private   void  MainMap_MouseUp( object  sender, MouseEventArgs e)
        {
             if  (e.Button  ==  MouseButtons.Left)
            {
                 this .isMouseDown  =   false ;
            }
        } 

 

 

保存截图的操作如下所示

代码

         private   void  tsbSavePicture_Click( object  sender, EventArgs e)
        {
             try
            {
                 using  (SaveFileDialog dialog  =   new  SaveFileDialog())
                {
                    dialog.Filter  =   " PNG (*.png)|*.png " ;
                    dialog.FileName  =   " GMap.NET image " ;
                    Image image  =   this .gMapControl1.ToImage();
                     if  (image  !=   null )
                    {
                         using  (image)
                        {
                             if  (dialog.ShowDialog()  ==  DialogResult.OK)
                            {
                                 string  fileName  =  dialog.FileName;
                                 if  ( ! fileName.EndsWith( " .png " , StringComparison.OrdinalIgnoreCase))
                                {
                                    fileName  +=   " .png " ;
                                }
                                image.Save(fileName);
                                MessageBox.Show( " 图片已保存：  "   +  dialog.FileName,  " GMap.NET " , MessageBoxButtons.OK, MessageBoxIcon.Asterisk);
                            }
                        }
                    }
                }
            }
             catch  (Exception exception)
            {
                MessageBox.Show( " 图片保存失败：  "   +  exception.Message,  " GMap.NET " , MessageBoxButtons.OK, MessageBoxIcon.Hand);
            }

 

 

地址查询并绘制图标的代码如下：

代码

private   void  btnSearch_Click( object  sender, EventArgs e)
        {
             if  ( this .txtAddress.Text.Length  ==   0 )
            {
                 this .txtAddress.Focus();
                MessageBox.Show( " 请输入查询的地址 " );
            }

             string  search  =   string .Format( " {0},{1} " ,  this .txtCity.Text,  this .txtAddress.Text);
            GeoCoderStatusCode code  =   this .gMapControl1.SetCurrentPositionByKeywords(search);
             if  (code  !=  GeoCoderStatusCode.G_GEO_SUCCESS)
            {
                MessageBox.Show( " 地址没有找到：' "   +   this .txtAddress.Text  +   " ', 原因： "   +  code.ToString(),  " GMap.NET " , MessageBoxButtons.OK, MessageBoxIcon.Exclamation);
            }

             this .objects.Markers.Clear();
            AddLocation( this .txtAddress.Text);
        }

         private   void  AddLocation( string  place)
        {
            GeoCoderStatusCode unknow  =  GeoCoderStatusCode.Unknow;
            PointLatLng ?  latLngFromGeocoder  =  Singleton < GMaps > .Instance.GetLatLngFromGeocoder(place,  out  unknow);
             if  (latLngFromGeocoder.HasValue  &&  (unknow  ==  GeoCoderStatusCode.G_GEO_SUCCESS))
            {
                GMapMarker item  =   new  GMapMarkerGoogleGreen(latLngFromGeocoder.Value);
                GMapMarkerRect rect  =   new  GMapMarkerRect(latLngFromGeocoder.Value);
                rect.Size  =   new  System.Drawing.Size( 100 ,  100 );
                rect.ToolTipText  =  place;
                rect.TooltipMode  =  MarkerTooltipMode.Always;
                 this .objects.Markers.Add(item);
                 this .objects.Markers.Add(rect);
            }
        }

 

 

绘制两地之间的线路图命令如下所示：

代码

         private   void  ctxMenu_GetRout_Click( object  sender, EventArgs e)
        {
             this .objects.Markers.Clear();
             this .routes.Routes.Clear(); // 清楚路线

             this .start  =  defaultLocation;
             this .end  =   this .gMapControl1.FromLocalToLatLng( this .contextMenuStrip1.Bounds.X,  this .contextMenuStrip1.Bounds.Y);

            MapRoute route  =  Singleton < GMaps > .Instance.GetRouteBetweenPoints( this .start,  this .end,  false , ( int ) this .gMapControl1.Zoom);
             if  (route  !=   null )
            {
                GMapRoute item  =   new  GMapRoute(route.Points, route.Name);
                item.Color  =  Color.Blue;
                 this .routes.Routes.Add(item);

                GMapMarker marker  =   new  GMapMarkerGoogleRed( this .start);
                 // marker.ToolTipText = "Start: " + route.Name;
                marker.TooltipMode  =  MarkerTooltipMode.Always;

                 // Placemark place = this.gMapControl1.Manager.GetPlacemarkFromGeocoder(this.end); // 地标不准确，不用
                MapRoute mapRoute  =   this .gMapControl1.Manager.GetRouteBetweenPoints( this .start,  this .end,  true , ( int ) this .gMapControl1.Zoom);
                GMapMarker marker2  =   new  GMapMarkerGoogleGreen( this .end);
                marker2.ToolTipText  =   string .Format( " 目的地距离:{0}公里  " , Math.Round(mapRoute.Distance,  2 ));
                marker2.TooltipMode  =  MarkerTooltipMode.Always;

                 this .objects.Markers.Add(marker);
                 this .objects.Markers.Add(marker2);
                 this .gMapControl1.ZoomAndCenterRoute(item);
            }            
        }

 

 

放大、缩小、重新加载地图的操作如下：

代码

         private   void  ctxMenu_ZoomOut_Click( object  sender, EventArgs e)
        {
             this .gMapControl1.Zoom  +=   1 ;            
        }

         private   void  ctxMenu_ZoomIn_Click( object  sender, EventArgs e)
        {
             this .gMapControl1.Zoom  -=   1 ;
        }

         private   void  tsbReload_Click( object  sender, EventArgs e)
        {
             this .gMapControl1.ReloadMap();
        }

 

 

程序截图如下所示：

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