PIE SDK地图书签

地图书签，可以理解为暂时记录当前地图的范围和放大级别，在后续的操作中如果想回到地图之前的状态，就可以点击保存的书签就可以回到此状态，如图所示：

地图刚加载的时候是一幅世界地图

我们将地图的中心拖到南美洲，将地图放大到一定比例，创建以“南美洲”为名称的书签，如下图所示：

创建后书签，在地图上随意拖动地图，并进行放大或缩小，然后点击“南美洲”书签，地图会定位到书签的南美洲视图范围。

下面来介绍下实现的主要代码：

要实现地图书签功能主要有两个步骤：

1、如何创建书签；

2、点击书签地图如何定位到书签的范围

一、创建书签

显示书签的列表用的是Devexpress插件中的 LayoutControl控件，

将要保存书签的视图范围输出为图片.png格式，然后用文件流将图片转换成Image，显示在书签列表中。示例中创建的书签信息数据存储在字典表IDictionary<string,object> m_DicBookMarkInfo中，其中值存储形式格式定义的是结构体BookMarkInfo，书签信息数据可以根据数据库的不同进行存储；

 /// <summary>

 /// 存储书签信息结构体

 /// </summary>

 public struct BookMarkInfo

 {

     public string key;//书签名称

     public LayoutControlItem layoutControlItem;//书签子控件

     public PIE.Geometry.IEnvelope envelope;//书签范围

     public PictureBox image;//书签范围图片

     public PIE.Geometry.ISpatialReference spatialReference;//空间参考

 }

 /// <summary>

 /// 添加地图书签

 /// </summary>

 /// <param name="sender"></param>

 /// <param name="e"></param>

 private void tbn_AddBookMark_Click(object sender, EventArgs e)

 {

     //1、获取书签的名称

     FrmAddBookMark bookMark = new FrmAddBookMark(m_DicBookMarkInfo);

     if (bookMark.ShowDialog() != DialogResult.OK) return;

     m_BookMarkName = bookMark.GetBookMarkName();

     if (string.IsNullOrEmpty(m_BookMarkName)) return;

     //2、输出图片

     IDisplayTransformation displayTransformation = mapControlMain.ActiveView.DisplayTransformation;

     PIE.Carto.ExportPNG export = new ExportPNG();

     export.Width = (int)displayTransformation.DeviceFrame.Width;

     export.Height = (int)displayTransformation.DeviceFrame.Height;

     export.ExportFileName = @"..\Data\Bookmark\pic\" + m_BookMarkName + ".png";

     string filePath = Path.GetDirectoryName(export.ExportFileName);

     if (!Directory.Exists(filePath))

     {

         Directory.CreateDirectory(filePath);

     }

     export.StartExporting();

     mapControlMain.ActiveView.Output(export as IExport, , displayTransformation.DeviceFrame, mapControlMain.ActiveView.Extent, null);

     export.FinishExporting();

     //3、界面设计（将图片展示在书签列表）

     Design(export.ExportFileName);

 }

 /// <summary>

 /// 书签界面设计

 /// </summary>

 /// <param name="filePath">输出图片路径</param>

 private void Design(string filePath)

 {

     PictureBox pictureBox1 = new PictureBox();

     //将保存的图片展示在书签列表

     using (FileStream image = new FileStream(filePath, FileMode.Open))

     {

         pictureBox1.Image = Image.FromStream(image);

     }

     LayoutControlItem item = layoutControlGroup1.AddItem(m_BookMarkName, pictureBox1) as LayoutControlItem;

     item.Name = m_BookMarkName;

     pictureBox1.SizeMode = PictureBoxSizeMode.StretchImage;

     IEnvelope envelope = m_ActiveView.Extent;

     pictureBox1.Name = m_BookMarkName;

     pictureBox1.Size = new Size(, );

     pictureBox1.Enabled = false;

     //事件

     item.Click += ItemPictureBox_Click;

     item.DoubleClick += ItemPictureBox_DoubleClick;

     item.SizeConstraintsType = DevExpress.XtraLayout.SizeConstraintsType.Custom;

     item.MaxSize = new Size(, );

     item.MinSize = new Size(, );

     item.TextLocation = DevExpress.Utils.Locations.Bottom;

     item.AppearanceItemCaption.TextOptions.HAlignment = DevExpress.Utils.HorzAlignment.Center;

     item.Spacing = new DevExpress.XtraLayout.Utils.Padding();

     item.AppearanceItemCaption.Font = new System.Drawing.Font("宋体", 13F, FontStyle.Bold);

     //存储标签信息

     BookMarkInfo bookMarkInfo = new BookMarkInfo();

     bookMarkInfo.key = m_BookMarkName;

     bookMarkInfo.layoutControlItem = item;

     bookMarkInfo.envelope = envelope;

     bookMarkInfo.image = pictureBox1;

     bookMarkInfo.spatialReference = mapControlMain.FocusMap.SpatialReference;

     m_DicBookMarkInfo.Add(m_BookMarkName, bookMarkInfo);//将信息存进字典表中

 }

二、点击书签地图定位书签的范围

点击书签分为单击和双击，单击时选中书签，双击时，地图范围更新变化，单击时：选中书签，其他选中的书签设置为不选中

 /// <summary>

 /// 单击事件

 /// </summary>

 /// <param name="sender"></param>

 /// <param name="e"></param>

 void ItemPictureBox_Click(object sender, EventArgs e)

 {

     LayoutControlItem item = (LayoutControlItem)sender;

     m_SelectedBookMarkName = item.Name;

     item.Selected = true;

     foreach (String key in m_DicBookMarkInfo.Keys)

     {

         if (key != item.Name)

         {

             BookMarkInfo structBookMark = new BookMarkInfo();

             structBookMark = (BookMarkInfo)m_DicBookMarkInfo[key];

            LayoutControlItem otherItem = structBookMark.layoutControlItem;

             otherItem.Selected = false;

         }

     }

 }

双击时：获取存储的选中对应书签的范围，并根据地图坐标系的不同进行转换，然后将地图的视图更新为选中书签的范围

 /// <summary>

 /// 双击标签图片

 /// </summary>

 /// <param name="sender"></param>

 /// <param name="e"></param>

 void ItemPictureBox_DoubleClick(object sender, EventArgs e)

 {

     LayoutControlItem pb = (LayoutControlItem)sender;

     pan(pb);

 }

     /// <summary>

     /// 定位函数

     /// </summary>

     /// <param name="pb">书签控件</param>

     private void pan(LayoutControlItem pb)

     {

     BookMarkInfo structBookMarkInfo = new BookMarkInfo();

     structBookMarkInfo = (BookMarkInfo)m_DicBookMarkInfo[pb.Name];

     IEnvelope envelope = structBookMarkInfo.envelope;

     IPointCollection polygon = new Polygon();

     String name = pb.Name;

     polygon.AddPoint(transform(envelope.XMax, envelope.YMax, name, ), transform(envelope.XMax, envelope.YMax, name, ));

     polygon.AddPoint(transform(envelope.XMin, envelope.YMax, name, ), transform(envelope.XMin, envelope.YMax, name, ));

     polygon.AddPoint(transform(envelope.XMax, envelope.YMin, name, ), transform(envelope.XMax, envelope.YMin, name, ));

     polygon.AddPoint(transform(envelope.XMin, envelope.YMin, name, ), transform(envelope.XMin, envelope.YMin, name, ));

     IGeometry geometry = polygon as IGeometry;

     m_ActiveView.ZoomTo(geometry);

     m_ActiveView.PartialRefresh(ViewDrawPhaseType.ViewAll);

     LayoutControlItem item = structBookMarkInfo.layoutControlItem;

     item.Selected = true;

     foreach (String key in m_DicBookMarkInfo.Keys)

     {

         if (key != item.Name)

         {

             BookMarkInfo structBookMark = new BookMarkInfo();

             structBookMark = (BookMarkInfo)m_DicBookMarkInfo[key];

             LayoutControlItem otherItem = structBookMark.layoutControlItem;

             otherItem.Selected = false;

         }

     }

     }

     /// <summary>

     /// 不同坐标系间坐标转换函数

     /// </summary>

     /// <param name="x">原坐标系x坐标</param>

     /// <param name="y">原坐标系x坐标</param>

     /// <param name="name">书签名称</param>

     /// <param name="flag">判断返回x或y的对象</param>

     /// <returns>转换后xy坐标</returns>

     private double transform(double x, double y, String name, int flag)

     {

     BookMarkInfo structBookMarkInfo = new BookMarkInfo();

     structBookMarkInfo = (BookMarkInfo)m_DicBookMarkInfo[name];

     // 定义点

     IPoint point = new PIE.Geometry.Point();

     point.PutCoords(x, y);

     // 设置空间参考

     IGeometry geo = point as IGeometry;

     geo.SpatialReference = structBookMarkInfo.spatialReference;

     // 空间参考变换

     geo.Transform(m_ActiveView.FocusMap.SpatialReference);

     // 获取坐标值

     double x1, y1;

     x1 = y1 = ;

     point.QueryCoords(ref x1, ref y1);

     if (flag == ) return x1;

     else return y1;

     }

代码路径：

项目名称	百度云盘地址下/PIE示例程序/13.小工具集锦/地图书签/ BookMarkDemo
数据路径	百度云盘地址下/PIE示例数据/栅格数据/04.World/World.tif
视频路径	百度云盘地址下/PIE视频教程/13.小工具集锦/地图书签.avi

注意：

在地图初始化的时候，图层树控件需要手动绑定地图控件：

tocControlMain.SetBuddyControl(mapControlMain as PIE.Carto.IPmdContents);

效果图：

巴特西

PIE SDK地图书签

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