Idx文件读取(dat/zb)示例

【实例截图】

【核心代码】

using System;
using System.Collections.Generic;
using System.ComponentModel;
using System.Data;
using System.Drawing;
using System.Linq;
using System.Text;
using System.Windows.Forms;
using System.IO;

namespace Sample
{
    public partial class ImageShowForm : Form
    {
        
        private long imageCount;
        private Int64 length;
        private Int64 offSet;
        private Int64 mapId;
        private int level;
        private Double minL;
        private Double minB;
        private Double maxL;
        private Double maxB;
        private string[] datFile;
        public ImageShowForm()
        {
            InitializeComponent();
        }

        private void exportButton_Click(object sender, EventArgs e)
        {
            openFileDialog.ShowDialog();
            Stream fileStream = openFileDialog.OpenFile();
            FileStream datStream=null;
            FileStream zbStream = null;
            if(openFileDialog.FileName!=null)
            {
                datFile = openFileDialog.FileName.Split('.');
                datStream = File.OpenRead(datFile[0]   ".dat");
                zbStream = File.OpenRead(datFile[0]   ".zb");
            }

            this.FileToStream(fileStream, datStream, zbStream);
        }

        public void FileToStream(Stream fileStream,Stream datStream,Stream zbStream)
        {
            progressBar.Show();
            //计算图片总张数
            imageCount = fileStream.Length / 20;
           
            byte[] bytes = new byte[8];
            byte[] lenbyte = new byte[4];

           
            for (int i = 1; i < imageCount;i  )
            {
                //读取index文件信息每20个字节读取信息
                fileStream.Seek(i * 20, SeekOrigin.Begin);
                //读取地图编号
                fileStream.Read(bytes, 0, 8);
                mapId = BitConverter.ToInt64(bytes,0);
                //读取偏移量
                fileStream.Read(bytes, 0, 8);
                offSet = BitConverter.ToInt64(bytes, 0);
                //获取图片的长度
                fileStream.Read(lenbyte, 0, 4);
                length = BitConverter.ToInt32(lenbyte, 0);

                byte[] datbytes = new byte[length];
                byte[] zbbytes = new byte[8];
                datStream.Position = 0;
                //根据偏移量和图片长度获取图片的二进制流
                datStream.Seek(offSet,SeekOrigin.Begin);
                datStream.Read(datbytes, 0, (int)length);
                
                if(datbytes!=null)
                {
                    try
                    {
                        Stream ms = new MemoryStream(datbytes);
                        //将二进制流直接付给图片
                        Image img = new Bitmap(ms, true);
                        pictureBox.Image = img;
                        pictureBox.Refresh();
                        ms.Close();
                        ms.Dispose();
                        img.Dispose();
                        progressBar.Maximum = (int)imageCount;
                        progressBar.Value=i;
                    }
                    catch(Exception ex)
                    {

                    }
                }
                //获取坐标等信息
                zbStream.Seek(i * 36, SeekOrigin.Begin);

                zbStream.Read(zbbytes, 0, 4);
                level = BitConverter.ToInt16(zbbytes, 0);
                zbStream.Read(zbbytes, 0, 8);
                minL = BitConverter.ToDouble(zbbytes, 0);
                zbStream.Read(zbbytes, 0, 8);
                minB = BitConverter.ToDouble(zbbytes, 0);
                zbStream.Read(zbbytes, 0, 8);
                maxL = BitConverter.ToDouble(zbbytes, 0);
                zbStream.Read(zbbytes, 0, 8);
                maxB = BitConverter.ToDouble(zbbytes, 0);
                showInfoRichTextBox.Text = "图片编号：" mapId "\n"
                      "偏移量：" offSet "\n"
                      "等级：" level "\n"
                     "最小经度：" minL "\n" "最小纬度：" minB "\n"
                     "最大经度：" maxL "\n" "最大纬度：" maxB "\n";
                showInfoRichTextBox.Refresh();

            }

            datStream.Close();
            fileStream.Close();

            progressBar.Hide();
        } 
    }
}