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, 96, 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(300, 100);
    pictureBox1.Enabled = false;

    //事件
    item.Click += ItemPictureBox_Click;
    item.DoubleClick += ItemPictureBox_DoubleClick;

    item.SizeConstraintsType = DevExpress.XtraLayout.SizeConstraintsType.Custom;
    item.MaxSize = new Size(250, 150);
    item.MinSize = new Size(250, 150);
    item.TextLocation = DevExpress.Utils.Locations.Bottom;

    item.AppearanceItemCaption.TextOptions.HAlignment = DevExpress.Utils.HorzAlignment.Center;
    item.Spacing = new DevExpress.XtraLayout.Utils.Padding(10);
    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, 1), transform(envelope.XMax, envelope.YMax, name, 2));
    polygon.AddPoint(transform(envelope.XMin, envelope.YMax, name, 1), transform(envelope.XMin, envelope.YMax, name, 2));
    polygon.AddPoint(transform(envelope.XMax, envelope.YMin, name, 1), transform(envelope.XMax, envelope.YMin, name, 2));
    polygon.AddPoint(transform(envelope.XMin, envelope.YMin, name, 1), transform(envelope.XMin, envelope.YMin, name, 2));
    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 = 0;
    point.QueryCoords(ref x1, ref y1);
    if (flag == 1) 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：