//調(diào)用windows API獲取磁盤空閑空間
//導(dǎo)入庫
[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>
/// 獲取指定路徑的大小
/// </summary>
/// <param name="dirPath">路徑</param>
/// <returns></returns>
public static long GetDirectoryLength(string dirPath)
{
long len = 0;
//判斷該路徑是否存在（是否為文件夾）
if (!Directory.Exists(dirPath))
{
//查詢文件的大小
len = FileSize(dirPath);
}
else
{
//定義一個DirectoryInfo對象
DirectoryInfo di = new DirectoryInfo(dirPath);

//通過GetFiles方法，獲取di目錄中的所有文件的大小
foreach (FileInfo fi in di.GetFiles())
{
len += fi.Length;
}
//獲取di中所有的文件夾，并存到一個新的對象數(shù)組中，以進行遞歸
DirectoryInfo[] dis = di.GetDirectories();
if (dis.Length > 0)
{
for (int i = 0; i < dis.Length; i++)
{
len += GetDirectoryLength(dis[i].FullName);
}
}
}
return len;
}

/// <summary>
/// 獲取指定路徑的占用空間
/// </summary>
/// <param name="dirPath">路徑</param>
/// <returns></returns>
public static long GetDirectorySpace(string dirPath)
{
//返回值
long len = 0;
//判斷該路徑是否存在（是否為文件夾）
if (!Directory.Exists(dirPath))
{
//如果是文件，則調(diào)用
len = FileSpace(dirPath);
}
else
{
//定義一個DirectoryInfo對象
DirectoryInfo di = new DirectoryInfo(dirPath);
//本機的簇值
long clusterSize = GetClusterSize(di);
//遍歷目錄下的文件，獲取總占用空間
foreach (FileInfo fi in di.GetFiles())
{
//文件大小除以簇，余若不為0
if (fi.Length % clusterSize != 0)
{
decimal res = fi.Length / clusterSize;
//文件大小除以簇，取整數(shù)加1。為該文件占用簇的值
int clu = Convert.ToInt32(Math.Ceiling(res)) + 1;
long result = clusterSize * clu;
len += result;
}
else
{
//余若為0，則占用空間等于文件大小
len += fi.Length;
}
}
//獲取di中所有的文件夾，并存到一個新的對象數(shù)組中，以進行遞歸
DirectoryInfo[] dis = di.GetDirectories();
if (dis.Length > 0)
{
for (int i = 0; i < dis.Length; i++)
{
len += GetDirectorySpace(dis[i].FullName);
}
}
}
return len;
}

//所給路徑中所對應(yīng)的文件大小
public static long FileSize(string filePath)
{
//定義一個FileInfo對象，是指與filePath所指向的文件相關(guān)聯(lián)，以獲取其大小
FileInfo fileInfo = new FileInfo(filePath);
return fileInfo.Length;
}

//所給路徑中所對應(yīng)的文件占用空間
public static long FileSpace(string filePath)
{
long temp = 0;
//定義一個FileInfo對象，是指與filePath所指向的文件相關(guān)聯(lián)，以獲取其大小
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);

//每簇的扇區(qū)數(shù)
diskInfo.SectorsPerCluster = sectorsPerCluster;
//每扇區(qū)字節(jié)
diskInfo.BytesPerSector = bytesPerSector;

return diskInfo;
}

//// <summary>
/// 結(jié)構(gòu)。硬盤信息
/// </summary>
public struct DiskInfo
{
public string RootPathName;
//每簇的扇區(qū)數(shù)
public int SectorsPerCluster;
//每扇區(qū)字節(jié)
public int BytesPerSector;
public int NumberOfFreeClusters;
public int TotalNumberOfClusters;
}
/// <summary>
/// 獲取每簇的字節(jié)
/// </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>
/// 獲取每簇的字節(jié)
/// </summary>
/// <param name="dir">指定目錄</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;
}