Question

完全重复： Getting the size (free,total) of a Windows Mobile phone drive using c#

<小时/> 亲爱的;

我知道我的问题花了很多时间，很多你帮助了我，但我是C＃的新手，这是我的第一个应用程序..

现在我读了一篇文章：

C＃签名：

  [DllImport("coredll.dll", SetLastError=true, CharSet=CharSet.Auto)]
  [return: MarshalAs(UnmanagedType.Bool)]
  static extern bool GetDiskFreeSpaceEx(string lpDirectoryName,
                                        out ulong lpFreeBytesAvailable,
                                        out ulong lpTotalNumberOfBytes,
                                        out ulong lpTotalNumberOfFreeBytes);

示例代码：

   ulong FreeBytesAvailable;
   ulong TotalNumberOfBytes;
   ulong TotalNumberOfFreeBytes;

   bool success = GetDiskFreeSpaceEx("C:\\", out FreeBytesAvailable, out  
                                    TotalNumberOfBytes,out TotalNumberOfFreeBytes);
   if (!success)
         throw new System.ComponentModel.Win32Exception();

   Console.WriteLine("Free Bytes Available:      {0,15:D}", FreeBytesAvailable);
   Console.WriteLine("Total Number Of Bytes:     {0,15:D}", TotalNumberOfBytes);
   Console.WriteLine("Total Number Of FreeBytes: {0,15:D}", TotalNumberOfFreeBytes);

现在如何使用此函数GetDiskFreeSpaceEx，我应该将C＃签名添加到某个地方？！？那coredll.dll怎么样？！？

我的代码是这样的：

  FolderInfo = (CONADefinitions.CONAPI_FOLDER_INFO)Marshal.PtrToStructure(Buffer,     
                                      typeof(CONADefinitions.CONAPI_FOLDER_INFO));
  if (FolderInfo.pstrName[0].ToString() != "C" && level == 0) 
  {
      // here i want to get the Total Size of the currentDirectory and freeSize
      // i want them in Bytes
  }

我在谷歌搜索但我没有足够的经验知道正确的标签

日Thnx

Answer 1

基本上，你可以像任何其他静态方法一样调用它，就像这样：

FolderInfo = (CONADefinitions.CONAPI_FOLDER_INFO)Marshal.PtrToStructure(Buffer, typeof(CONADefinitions.CONAPI_FOLDER_INFO));
if (FolderInfo.pstrName[0].ToString() != "C" && level == 0) 
{
  ulong FreeBytesAvailable;
  ulong TotalNumberOfBytes;
  ulong TotalNumberOfFreeBytes;

  bool success = GetDiskFreeSpaceEx("C:\\", out FreeBytesAvailable, out TotalNumberOfBytes,out TotalNumberOfFreeBytes);

  if (!success)
    throw new System.ComponentModel.Win32Exception();
}

我建议创建一个包装器来处理抛出异常（除非你想每次检查返回值而不处理异常）：

[DllImport("coredll.dll", SetLastError=true, CharSet=CharSet.Auto, EntryPoint="GetDiskFreeSpaceEx")]
[return: MarshalAs(UnmanagedType.Bool)]
static extern bool InternalGetDiskFreeSpaceEx(string lpDirectoryName, out ulong lpFreeBytesAvailable, out ulong lpTotalNumberOfBytes, out ulong lpTotalNumberOfFreeBytes);

static GetDiskFreeSpaceEx(string directoryName, out ulong freeBytesAvailable, out ulong totalNumberOfBytes, out totalNumberOfFreeBytes);
{
  if (!GetDiskFreeSpaceEx(directoryName, out freeBytesAvailable, out totalNumberOfBytes, out totalNumberOfFreeBytes))
    throw new System.ComponentModel.Win32Exception();
}

呼叫网站将成为：

FolderInfo = (CONADefinitions.CONAPI_FOLDER_INFO)Marshal.PtrToStructure(Buffer, typeof(CONADefinitions.CONAPI_FOLDER_INFO));
if (FolderInfo.pstrName[0].ToString() != "C" && level == 0) 
{
  ulong FreeBytesAvailable;
  ulong TotalNumberOfBytes;
  ulong TotalNumberOfFreeBytes;

  GetDiskFreeSpaceEx("C:\\", out FreeBytesAvailable, out TotalNumberOfBytes,out TotalNumberOfFreeBytes);
}

Answer 2

您的原始代码确实令人困惑，您可以使用上一个问题original question here中链接的原始代码。事实上，你不应该首先打开另一个问题，但应该在原文中添加评论，要求进一步澄清。

您有P / Invoke定义。这只是一个静态方法调用。你把它放在课堂上。像这样：

public class MyClass
{
  [DllImport("coredll.dll", SetLastError=true, CharSet=CharSet.Auto)]
  [return: MarshalAs(UnmanagedType.Bool)]
  internal static extern bool GetDiskFreeSpaceEx(string lpDirectoryName,
    out ulong lpFreeBytesAvailable,
    out ulong lpTotalNumberOfBytes,
    out ulong lpTotalNumberOfFreeBytes);
}

然后你打电话给它（不知道你想要用你所有的编组工作做什么）：

ulong GetDiskSize(string volumeName)
{
  ulong avail;
  ulong total;
  ulong totalfree;

  MyClass.GetDiskFreeSpaceEx(volumeName, out avail, out total, out totalFree);

  return total;
  // return others as desired
}

然后使用它就像这样：

ulong diskSize = GetDiskSize("\\Storage Card");

P /调用GetDiskFreeSpaceEx

2 个答案: