如何在WPF Bing地图中序列化MapPolyline?

问题描述

大家好，我想将WPF Bing地图上的MapPolyline序列化为文件，关闭程序，然后再次启动程序并加载文件，以便在地图上还原该MapPolyline.我不知道如何使这项工作.请你帮助我好吗 解决这个问题?提前致谢.

Hi everyone, I want to serialize a MapPolyline on WPF Bing map to a file, close the program, then start the program again and load the file in order to restore that MapPolyline on the map. I couldn't figure how to make this work. Could you please help me to solve this? Thanks in advance.

这是我的代码:

private void Save(object sender, RoutedEventArgs e)
{
System.Windows.Forms.SaveFileDialog saveFile = new System.Windows.Forms.SaveFileDialog();
            saveFile.Filter = "XML Files (*.xml)|*.xml|All Files (*.*)|*.*";
            saveFile.FileName = string.Format("{0:MM-dd-yyyy HH.mm.ss}", DateTime.Now);
            saveFile.DefaultExt = ".xml";
            saveFile.InitialDirectory = @"c:\BingMapApp\BingMapState";            

            if (saveFile.ShowDialog() == System.Windows.Forms.DialogResult.OK)
            {
                string filename = saveFile.FileName;
                FileStream Fs = new FileStream(filename, FileMode.Create);               

                foreach (UIElement element in MainMap.Children)
                {
                    if (element is MapPolyline)
                    {
                        MapPolyline polyline = element as MapPolyline;
                        XamlWriter.Save(polyline, Fs);
                    }
                }
                Fs.Close();
}
}

private void Load(object sender, RoutedEventArgs e)
{

System.Windows.Forms.OpenFileDialog openFile = new System.Windows.Forms.OpenFileDialog();
            openFile.Filter = "XML Files (*.xml)|*.xml|All Files (*.*)|*.*";

            if (openFile.ShowDialog() == System.Windows.Forms.DialogResult.OK)
            {                
                FileStream xamlFile = openFile.OpenFile() as FileStream;

                if (xamlFile == null) 
                    return;
                else
                {                    
                        MapPolyline element = XamlReader.Load(xamlFile) as MapPolyline;
                                               
                        xamlFile.Close();                     

                    }

}

此行存在错误:  MapPolyline元素= XamlReader.Load(xamlFile)为MapPolyline;

There's an error with this line: MapPolyline element = XamlReader.Load(xamlFile) as MapPolyline;

它说:'无法从文本'Microsoft.Maps.MapControl.WPF.LocationCollection'创建'位置'."

It said: "'Failed to create a 'Locations' from the text 'Microsoft.Maps.MapControl.WPF.LocationCollection'."

推荐答案

  private void Save(object sender, RoutedEventArgs e)
        {
            System.Windows.Forms.SaveFileDialog saveFile = new System.Windows.Forms.SaveFileDialog();
            saveFile.Filter = "XML Files (*.xml)|*.xml|All Files (*.*)|*.*";
            saveFile.FileName = string.Format("{0:MM-dd-yyyy HH.mm.ss}", DateTime.Now);
            saveFile.DefaultExt = ".xml";
            saveFile.InitialDirectory = @"c:\BingMapApp\BingMapState";

            if (saveFile.ShowDialog() == System.Windows.Forms.DialogResult.OK)
            {
                string filename = saveFile.FileName;
                FileStream Fs = new FileStream(filename, FileMode.Create);

                foreach (UIElement element in MainMap.Children)
                {
                    if (element is MapPolyline)
                    {
                        MapPolyline polyline = element as MapPolyline;
                        using (MemoryStream ms = new MemoryStream())
                        {
                            XamlWriter.Save(polyline, ms);
                            byte[] header = BitConverter.GetBytes(ms.Length);
                            Fs.Write(header, 0, header.Length);
                            byte[] data = ms.ToArray();
                            Fs.Write(data, 0, data.Length);
                        }
                    }
                }
                Fs.Close();
            }
        }

        private void Load(object sender, RoutedEventArgs e)
        {

            System.Windows.Forms.OpenFileDialog openFile = new System.Windows.Forms.OpenFileDialog();
            openFile.Filter = "XML Files (*.xml)|*.xml|All Files (*.*)|*.*";

            if (openFile.ShowDialog() == System.Windows.Forms.DialogResult.OK)
            {
                FileStream xamlFile = openFile.OpenFile() as FileStream;

                if (xamlFile == null)
                    return;
                else
                {
                    while (xamlFile.Position < xamlFile.Length - 1)
                    {
                        long len = 0;
                        byte[] header = BitConverter.GetBytes(len);
                        xamlFile.Read(header, 0, header.Length);
                        len = BitConverter.ToInt64(header, 0);

                        byte[] data = new byte[len];
                        xamlFile.Read(data, 0, data.Length);

                        using (MemoryStream ms = new MemoryStream(data))
                        {
                            //get one element
                            MapPolyline element = XamlReader.Load(ms) as MapPolyline; 

                            //add element to map
                            ...
                        }
                    }

                    xamlFile.Close();

                }

            }
        }

这篇关于如何在WPF Bing地图中序列化MapPolyline?的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持！