/// <summary>
/// 获取分卷文件的文件头结构
/// </summary>
/// <param name="fs">文件流，调用此方法文件指针将会重置到文件起始位置</param>
/// <returns></returns>
public CutedFileHead GetCutedFileHead(FileStream fs)
{
fs.Seek(0, SeekOrigin.Begin);
BinaryReader br = new BinaryReader(fs);
CutedFileHead head = new CutedFileHead();
head.Flag = br.ReadInt32();
if (head.Flag == CUT_FILE_FLAG)
{
head.Offset = br.ReadInt32();
head.FileNumber = br.ReadInt16();
head.FileCount = br.ReadInt16();
int strLength = head.Offset - 2 * sizeof(int) - 2 * sizeof(short);
head.FileName = System.Text.Encoding.Default.GetString(br.ReadBytes(strLength));
}
else
{
head.FileName = "无效的分卷文件。";
}
return(head);
}
/// <summary>
/// 链接文件。
/// </summary>
/// <param name="cutedFiles">切分的文件名数组</param>
/// <param name="descFolder">链接文件保存的目录，如果为空则采用第一个分卷文件所在的目录</param>
/// <param name="descFileName">链接文件的名称，不带路径。如果为空，则采用链接文件中记录的原始文件名</param>
/// <returns>链接后的文件名，如果操作不成功返回空</returns>
public string Link(string[] cutedFiles, string descFolder, string descFileName)
{
this.ProgressWorking = true;
this.CutedFiles = cutedFiles;
CutedFileHead[] heads = new CutedFileHead[cutedFiles.Length];
//List<string> sortedFiles = null;
if (!VerifyCutedFiles(cutedFiles, ref heads))//, out sortedFiles
{
return("");
}
if (string.IsNullOrEmpty(descFolder))
{
descFolder = System.IO.Path.GetDirectoryName(cutedFiles[0]);
}
else
{
if (!Directory.Exists(descFolder))
{
Directory.CreateDirectory(descFolder);
}
}
string sourceFileName = string.IsNullOrEmpty(descFileName) ? heads[0].FileName : descFileName;
FileStream fsDesc = null;//
try
{
fsDesc = File.Create(descFolder + "\\" + sourceFileName);
//开始合并文件
for (int i = 0; i < heads.Length; i++)
{
this.ProgressFileName = heads[i].MapFileName;
this.ProgresFileNumber = i;
using (FileStream fsRead = new FileStream(heads[i].MapFileName, FileMode.Open, FileAccess.Read))
{
this.ProgressFileSize = (int)fsRead.Length;
//定位到文件的正文开头
fsRead.Seek(heads[i].Offset, SeekOrigin.Begin);
int offset = 0;
int readCount = 0;
do
{
byte[] dataArray = new byte[SIZE];
readCount = fsRead.Read(dataArray, 0, SIZE);
if (readCount == 0)
{
break;
}
//可以将 offset 作为进度条信息给外面使用,建议使用时钟定期查询
offset += readCount;
this.ProgressFileRead = offset;
//模拟大文件，正式版本请注释下面一行代码
//System.Threading.Thread.Sleep(10);
//将当前块数据写入目标文件
fsDesc.Write(dataArray, 0, readCount);
} while (readCount == SIZE);
fsRead.Close();
fsRead.Dispose();
}
}//end for
//连接成功后删除源文件
if (this.DeleteFileArterLink)
{
for (int i = 0; i < heads.Length; i++)
{
File.Delete(heads[i].MapFileName);
}
}
}
catch (Exception ex)
{
this.ErrorMessage = ex.Message;
}
finally
{
if (fsDesc != null)
{
fsDesc.Close();
fsDesc.Dispose();
fsDesc = null;
}
}
this.ProgressWorking = false;
return(sourceFileName);
}
/// <summary>
/// 校验一组文件是否是有效的分组文件
/// </summary>
/// <param name="cutedFiles">要检查的源分卷文件数组</param>
/// <param name="heads">符合目标的文件头数组</param>
/// <returns></returns>
public bool VerifyCutedFiles(string[] cutedFiles, ref CutedFileHead[] heads)//, out List<string> sortedFiles
{
//sortedFiles = new List<string>();
this.ErrorMessage = "";
if (cutedFiles.Length <= 1)
{
this.ErrorMessage = "分卷文件需要至少2个。";
return(false);
}
//检查所有文件头信息
string checkMsg = "";
List <CutedFileHead> headList = new List <CutedFileHead>();//本次所有有效的文件头列表
for (int i = 0; i < cutedFiles.Length; i++)
{
CutedFileHead head = GetCutedFileHead(cutedFiles[i]);
if (head.Flag != CUT_FILE_FLAG)
{
checkMsg += "\r\n当前文件不是有效的分卷文件：" + cutedFiles[i];
//将无效文件删除
File.Delete(cutedFiles[i]);
}
else
{
head.MapFileName = cutedFiles[i];
headList.Add(head);
}
}
if (headList.Count <= 1)
{
//有效的分卷文件不够数量
this.ErrorMessage = "有效的分卷文件至少需要2个；" + checkMsg;
return(false);
}
List <CutedFileHead> checkedHeads = new List <CutedFileHead>(); //验证有效的文件文件列表
var firstHeads = headList.FindAll(p => p.FileNumber == 1); //先找到第一个分卷文件，可能有多个（比如分次发送不同大小的文件）
var foundOK = false;
foreach (CutedFileHead item in firstHeads)
{
checkedHeads.Clear();
checkedHeads.Add(item);
int fileCount = item.FileCount;//当前分卷文件对应的同类文件个数
for (int fileNumber = 2; fileNumber <= fileCount; fileNumber++)
{
var currtHeads = headList.FindAll(p => p.FileNumber == fileNumber && p.FileName == item.FileName).ToArray();
if (currtHeads.Length > 0)
{
//找到当前顺序的文件
checkedHeads.Add(currtHeads[0]);
}
else
{
//当前分卷文件不连续
break;
}
}
if (checkedHeads.Count == item.FileCount)
{
//寻找到有效的文件头列表
foundOK = true;
break;
}
}
if (foundOK)
{
heads = checkedHeads.ToArray();
return(true);
}
else
{
this.ErrorMessage = "分卷文件不连续!";
return(false);
}
}
