C#获取文件夹及文件的大小与占用空间的方法

//调用windows API获取磁盘空闲空间
//导入库
[DllImport("kernel32.dll", CharSet = CharSet.Auto)]
static extern bool GetDiskFreeSpace([MarshalAs(UnmanagedType.LPTStr)]string rootPathName,
ref int sectorsPerCluster, ref int bytesPerSector, ref int numberOfFreeClusters, ref int totalNumbeOfClusters);

/// <summary>
/// 获取指定路径的大小
/// </summary>
/// <param name="dirPath">路径</param>
/// <returns></returns>
public static long GetDirectoryLength(string dirPath)
{
long len = 0;
//判断该路径是否存在（是否为文件夹）
if (!Directory.Exists(dirPath))
{
//查询文件的大小
len = FileSize(dirPath);
}
else
{
//定义一个DirectoryInfo对象
DirectoryInfo di = new DirectoryInfo(dirPath);

//通过GetFiles方法，获取di目录中的所有文件的大小
foreach (FileInfo fi in di.GetFiles())
{
len += fi.Length;
}
//获取di中所有的文件夹，并存到一个新的对象数组中，以进行递归
DirectoryInfo[] dis = di.GetDirectories();
if (dis.Length > 0)
{
for (int i = 0; i < dis.Length; i++)
{
len += GetDirectoryLength(dis[i].FullName);
}
}
}
return len;
}

/// <summary>
/// 获取指定路径的占用空间
/// </summary>
/// <param name="dirPath">路径</param>
/// <returns></returns>
public static long GetDirectorySpace(string dirPath)
{
//返回值
long len = 0;
//判断该路径是否存在（是否为文件夹）
if (!Directory.Exists(dirPath))
{
//如果是文件，则调用
len = FileSpace(dirPath);
}
else
{
//定义一个DirectoryInfo对象
DirectoryInfo di = new DirectoryInfo(dirPath);
//本机的簇值
long clusterSize = GetClusterSize(di);
//遍历目录下的文件，获取总占用空间
foreach (FileInfo fi in di.GetFiles())
{
//文件大小除以簇，余若不为0
if (fi.Length % clusterSize != 0)
{
decimal res = fi.Length / clusterSize;
//文件大小除以簇，取整数加1。为该文件占用簇的值
int clu = Convert.ToInt32(Math.Ceiling(res)) + 1;
long result = clusterSize * clu;
len += result;
}
else
{
//余若为0，则占用空间等于文件大小
len += fi.Length;
}
}
//获取di中所有的文件夹，并存到一个新的对象数组中，以进行递归
DirectoryInfo[] dis = di.GetDirectories();
if (dis.Length > 0)
{
for (int i = 0; i < dis.Length; i++)
{
len += GetDirectorySpace(dis[i].FullName);
}
}
}
return len;
}

//所给路径中所对应的文件大小
public static long FileSize(string filePath)
{
//定义一个FileInfo对象，是指与filePath所指向的文件相关联，以获取其大小
FileInfo fileInfo = new FileInfo(filePath);
return fileInfo.Length;
}

//所给路径中所对应的文件占用空间
public static long FileSpace(string filePath)
{
long temp = 0;
//定义一个FileInfo对象，是指与filePath所指向的文件相关联，以获取其大小
FileInfo fileInfo = new FileInfo(filePath);
long clusterSize = GetClusterSize(fileInfo);
if (fileInfo.Length % clusterSize != 0)
{
decimal res = fileInfo.Length / clusterSize;
int clu = Convert.ToInt32(Math.Ceiling(res)) + 1;
temp = clusterSize * clu;
}
else
{
return fileInfo.Length;
}
return temp;
}

public static DiskInfo GetDiskInfo(string rootPathName)
{
DiskInfo diskInfo = new DiskInfo();
int sectorsPerCluster = 0, bytesPerSector = 0, numberOfFreeClusters = 0, totalNumberOfClusters = 0;
GetDiskFreeSpace(rootPathName, ref sectorsPerCluster, ref bytesPerSector, ref numberOfFreeClusters, ref totalNumberOfClusters);

//每簇的扇区数
diskInfo.SectorsPerCluster = sectorsPerCluster;
//每扇区字节
diskInfo.BytesPerSector = bytesPerSector;

return diskInfo;
}

//// <summary>
/// 结构。硬盘信息
/// </summary>
public struct DiskInfo
{
public string RootPathName;
//每簇的扇区数
public int SectorsPerCluster;
//每扇区字节
public int BytesPerSector;
public int NumberOfFreeClusters;
public int TotalNumberOfClusters;
}
/// <summary>
/// 获取每簇的字节
/// </summary>
/// <param name="file">指定文件</param>
/// <returns></returns>
public static long GetClusterSize(FileInfo file)
{
long clusterSize = 0;
DiskInfo diskInfo = new DiskInfo();
diskInfo = GetDiskInfo(file.Directory.Root.FullName);
clusterSize = (diskInfo.BytesPerSector * diskInfo.SectorsPerCluster);
return clusterSize;
}

/// <summary>
/// 获取每簇的字节
/// </summary>
/// <param name="dir">指定目录</param>
/// <returns></returns>
public static long GetClusterSize(DirectoryInfo dir)
{
long clusterSize = 0;
DiskInfo diskInfo = new DiskInfo();
diskInfo = GetDiskInfo(dir.Root.FullName);
clusterSize = (diskInfo.BytesPerSector * diskInfo.SectorsPerCluster);
return clusterSize;
}