c#遍历一个文件夹下的所有文件包括子文件夹【原】

/// <summary>
/// 遍历目录所有文件
/// </summary>
/// <param name="directory">目录</param>
/// <param name="searchPattern">要查找的文件（*.txt）</param>
/// <returns></returns>
public static FileInfo[] GetFileList(DirectoryInfo directory, string searchPattern)
{
FileInfo[] fis = new FileInfo[0];
DirectoryInfo[] directorys = directory.GetDirectories();
foreach (DirectoryInfo di in directorys)
{
FileInfo[] fiss = GetFileList(di,searchPattern);
AddNewArray<FileInfo>(ref fis, fiss);
}
AddNewArray<FileInfo>(ref fis, directory.GetFiles(searchPattern));
return fis;
}

/// <summary>
/// 遍历目录所有文件大小
/// </summary>
/// <param name="directory">目录</param>
/// <param name="searchPattern">要查找的文件（*.txt）</param>
/// <param name="symbol">是否带符号</param>
/// <returns></returns>
public static string GetFileListLength(DirectoryInfo directory, string searchPattern, bool symbol)
{
int fileListLength = 0;

foreach (FileInfo fi in GetFileList(directory, searchPattern))
{
fileListLength += (int)fi.Length;
}
return getSizeType(fileListLength, symbol);
}

/// <summary>
/// 合并数组
/// </summary>
/// <typeparam name="T"></typeparam>
/// <param name="A"></param>
/// <param name="B"></param>
public static void AddNewArray<T>(ref T[] A, T[] B)//合并数组，运用了一个范型，具体作用见下文
{
T[] A1;
A1 = (T[])A.Clone();
A = new T[A1.GetLength(0) + B.GetLength(0)];
for (int i = 0; i < A1.GetLength(0); i++)
{
A[i] = A1[i];
}
for (int i = 0; i < B.GetLength(0); i++)
{
A[i + A1.GetLength(0)] = B[i];
}
}

/// <summary>
/// 格式化大小符号
/// </summary>
/// <param name="fileSize"></param>
/// <param name="symbol">是否带符号</param>
/// <returns></returns>
public static string getSizeType(int fileSize, bool symbol)
{
string fileInfo = "0B";
if (fileSize > 0)
{
if (fileSize / 1024 > 0)
{
if (fileSize / 1024 / 1024 > 0)
{
if (fileSize / 1024 / 1024 / 1024 > 0)
{
fileInfo = (fileSize / 1024.0 / 1024.0 / 1024.0).ToString("0.0") + (symbol ? " GB" : "");
}
else
{
fileInfo = (fileSize / 1024.0 / 1024).ToString("0.0") + (symbol ? " MB" : "");
}
}
else
{
fileInfo = (fileSize / 1024.0).ToString("0.0") + (symbol ? " KB" : "");
}
}
else
{
fileInfo = fileSize + (symbol ? " B" : "");
}
}
return fileInfo;
}