wp7平台zip压缩处理

最近在wp7平台做一个push email 的客户端，通过socket连接接受下来的邮件内容是一个zip压缩包，需要在客户端解压处理。

windows phone 7 没有zip相关的API支持，最后找到一个开源的zip lib包slsharpziplib

地址是：http://slsharpziplib.codeplex.com

解压的代码

  /// <summary>
/// 解压zip包
/// </summary>
/// <param name="excludeFiles">压缩包中不需要解压处理的文件</param>
/// <param name="directoryName">解压到的目标路径</param>
/// <param name="sourceFile">待解压的zip包在isolatedStorage中的文件路径</param>
/// <returns></returns>
        public bool UnZip(List<String> excludeFiles, string directoryName, string sourceFile = ReceiveMailDataState.MailDataTempFileName)
        {
            bool ret = true;
            try
            {
                IsolatedStorageFile file = IsolatedStorageFile.GetUserStoreForApplication();
                using (IsolatedStorageFileStream fileStream = file.OpenFile(sourceFile, FileMode.Open, FileAccess.Read))
                {
                    ZipInputStream s = new ZipInputStream(fileStream);
                   // StreamReader reader = new StreamReader(s);
                    BinaryReader reader = new BinaryReader(s);
                    ZipEntry theEntry;
                    while ((theEntry = s.GetNextEntry()) != null)
                    {
                        string fileName = theEntry.Name;
                        if (fileName != String.Empty)
                        {
                            //如果文件的压缩后大小为0那么说明这个文件是空的,因此不需要进行读出写入
                            if (theEntry.CompressedSize == 0)
                                continue;
                            if (!theEntry.IsFile)
                                continue;
                            else if (!theEntry.IsCompressionMethodSupported())
                            {
                                continue;
                            }
                            else if (!theEntry.CanDecompress)
                            {
                                continue;
                            }
                            if (excludeFiles != null && excludeFiles.Contains(fileName))
                                continue;

                            String fullFileName = directoryName + PathSeperater + fileName;

                            //Ensure path exist
                            String path = fullFileName.Substring(0, fullFileName.LastIndexOf(PathSeperater));
                            if (!file.DirectoryExists(path))
                            {
                                file.CreateDirectory(path);
                            }

                            using (IsolatedStorageFileStream stream = file.CreateFile(fullFileName))
                            {
                                BinaryWriter writer = new BinaryWriter(stream);
                                int size = 2048;
                                byte[] data = new byte[2048];
                                while (true)
                                {
                                    size = reader.Read(data, 0, data.Length);
                                    if (size > 0) { writer.Write(data, 0, size); }
                                    else { break; }
                                }
                                writer.Close();
                                stream.Close();
                            }
                        }
                    }
                    s.Close();
                }
            }
            catch (Exception ex) {
                Debug.WriteLine(ex.Message);
                ret = false; 
            }
            return ret;
        }

解压过程的时候抛出异常

Library cannot extract this entry. Version required is (788).

解决办法：

在slsharpziplib for wp7的源代码中找到ZipEntry类，找到property Version，修改如下，取Version的低字节

public int Version
{
get
{
// Return recorded version if known.
if (_versionToExtract != 0)
{
return _versionToExtract & 0x00ff;
}

至于修改的原因，跟zip格式的结构有关，我将翻译一篇相关资料来解释，敬请期待。

修改完以后重新编译和使用这个包就解压成功了。

在cmd命令行中输入ISETool.exe ts de 23833d6c-1446-4097-a7f6-358c3294d9a3 "C:\Temp"

ISETool命令的用法请看我的文章IsolatedStorage工具使用介绍

把解压后的文件拷贝到C:\Temp目录下，可以看到原来的zip文件解压了

2011/12/02 13:01 <DIR> htmls
2011/12/02 13:01 <DIR> images
2011/12/02 13:01 472 index.xml
2011/12/02 13:01 <DIR> mimes

 

 

xiaobai

devxiaobai@gamil.com