C＃日常开发随手记------获取华为云桶中ZIP内的所有文件(包含System.NotSupportedException:“此流不支持查找操作“解决方法)

需求：根据华为云桶的文件下载地址，展示出目标ZIP文件内的所有文件信息

/// <summary>
/// 获取目标ZIP文件内的所有文件信息
/// </summary>
/// <param name="stream">文件流</param>
/// <param name="fileList">返回的结果集</param>
/// <returns></returns>
private IList<fileInfo> GetFileInfoForZip(Stream stream,out IList<fileInfo> fileList)
{
    
	//声明返回的结果集
	fileList = new List<fileInfo>();
	stream.Position = 0;
	var factory = ArchiveFactory.Open(stream);
	foreach (var item in factory.Entries)
	{
    
		fileInfo fil = new fileInfo();

		var memoryStream = new MemoryStream();
		var entryStream = item.OpenEntryStream();
		//entryStream.Position = 0;
		if (entryStream != null)
		{
    
			entryStream.CopyTo(memoryStream);
			entryStream.Dispose();
		}
		fil.Name = item.Key;
		fil.size = item.Size.ToString();
		fil.Time = item.LastModifiedTime.ToString();
		fileList.Add(fil);
	}

	return fileList;
}

/// <summary>
/// 流转换方法----直接转Stream流会出现 System.NotSupportedException:"此流不支持查找操作" 错误
/// </summary>
/// <param name="instream"></param>
/// <returns></returns>
MemoryStream StreamToMemoryStream(Stream instream)
{
    
	MemoryStream outstream = new MemoryStream();
	const int bufferLength = 4096;
	byte[] bl = new byte[bufferLength];
	int count = 0;
	while ((count = instream.Read(bl, 0, bufferLength)) > 0)
	{
    
		outstream.Write(bl, 0, count);
	}
	return outstream;
}

/// <summary>
/// 用到的文件信息类
/// </summary>
public class fileInfo
{
    
	/// <summary>
	/// 文件名
	/// </summary>
	public string Name;

	/// <summary>
	/// 文件大小
	/// </summary>
	public string size;

	/// <summary>
	/// 创建时间
	/// </summary>
	public string Time;
}

//按钮的触发事件
protected void btn_Text_Click(object sender, EventArgs e)
{
    
	HttpWebRequest request = (HttpWebRequest)WebRequest.Create("url");
	HttpWebResponse response = request.GetResponse() as HttpWebResponse;
	if (response.StatusCode == HttpStatusCode.OK)
	{
    
		Stream rs = response.GetResponseStream();
		var ms = StreamToMemoryStream(rs);//rs.Length 此流不支持查找,先转为MemoryStream
		IList<fileInfo> fileList = new List<fileInfo>();
		GetFileInfoForZip(ms, out fileList);
	}
}

**

需求：根据本地地址获取目标Zip压缩包中的文件信息

**

/// <summary>
/// 根据附件地址获取附件中文件的信息
/// </summary>
/// <param name="filePath"></param>
/// <param name="fileList"></param>
/// <returns></returns>
public IList<fileInfo> getZipInfo(string filePath, out IList<fileInfo> fileList)
{
    
    //根据ItemId和itemFileId查询对应的文件信息（默认智能查询到一件，itemFileId为主键理应不会重复）
    fileList = new List<fileInfo>();
    //判断是否查询到数据
    var factory = ArchiveFactory.Open(filePath);
    foreach (var fileInfo in factory.Entries)
    {
    
        fileInfo fil = new fileInfo();

        fil.Name = fileInfo.Key;
        fil.size = fileInfo.Size.ToString();
        fil.Time = fileInfo.LastModifiedTime.ToString();
        fileList.Add(fil);
    }

    return fileList;
}

/// <summary>
/// 用到的文件信息类
/// </summary>
public class fileInfo
{
    
	/// <summary>
	/// 文件名
	/// </summary>
	public string Name;

	/// <summary>
	/// 文件大小
	/// </summary>
	public string size;

	/// <summary>
	/// 创建时间
	/// </summary>
	public string Time;
}