Interop.cs

Go to the documentation of this file.

using System;
using System.Runtime.InteropServices;
 
internal static class Interop
{
    internal static class Kernel32
    {
        [DllImport("kernel32.dll", BestFitMapping = false, CharSet = CharSet.Unicode, EntryPoint = "GetDriveTypeW", SetLastError = true)]
        internal static extern int GetDriveType(string drive);
 
        [DllImport("kernel32.dll", BestFitMapping = false, CharSet = CharSet.Unicode, EntryPoint = "GetVolumeInformationW", SetLastError = true)]
        internal unsafe static extern bool GetVolumeInformation(string drive, char* volumeName, int volumeNameBufLen, int* volSerialNumber, int* maxFileNameLen, out int fileSystemFlags, char* fileSystemName, int fileSystemNameBufLen);
 
        [DllImport("kernel32.dll", SetLastError = true)]
        internal static extern int GetLogicalDrives();
 
        [DllImport("kernel32.dll", BestFitMapping = false, CharSet = CharSet.Unicode, EntryPoint = "GetDiskFreeSpaceExW", SetLastError = true)]
        internal static extern bool GetDiskFreeSpaceEx(string drive, out long freeBytesForUser, out long totalBytes, out long freeBytes);
 
        [DllImport("kernel32.dll", BestFitMapping = false, CharSet = CharSet.Unicode, EntryPoint = "SetVolumeLabelW", SetLastError = true)]
        internal static extern bool SetVolumeLabel(string driveLetter, string volumeName);
 
        [DllImport("kernel32.dll", ExactSpelling = true, SetLastError = true)]
        [SuppressGCTransition]
        internal static extern bool SetThreadErrorMode(uint dwNewMode, out uint lpOldMode);
 
        [DllImport("kernel32.dll", BestFitMapping = true, CharSet = CharSet.Unicode, EntryPoint = "FormatMessageW", ExactSpelling = true, SetLastError = true)]
        private unsafe static extern int FormatMessage(int dwFlags, IntPtr lpSource, uint dwMessageId, int dwLanguageId, void* lpBuffer, int nSize, IntPtr arguments);
 
        internal static string GetMessage(int errorCode)
        {
            return GetMessage(errorCode, IntPtr.Zero);
        }
 
        internal unsafe static string GetMessage(int errorCode, IntPtr moduleHandle)
        {
            int num = 12800;
            if (moduleHandle != IntPtr.Zero)
            {
                num |= 0x800;
            }
            Span<char> span = stackalloc char[256];
            fixed (char* lpBuffer = span)
            {
                int num2 = FormatMessage(num, moduleHandle, (uint)errorCode, 0, lpBuffer, span.Length, IntPtr.Zero);
                if (num2 > 0)
                {
                    return GetAndTrimString(span.Slice(0, num2));
                }
            }
            if (Marshal.GetLastWin32Error() == 122)
            {
                IntPtr intPtr = default(IntPtr);
                try
                {
                    int num3 = FormatMessage(num | 0x100, moduleHandle, (uint)errorCode, 0, &intPtr, 0, IntPtr.Zero);
                    if (num3 > 0)
                    {
                        return GetAndTrimString(new Span<char>((void*)intPtr, num3));
                    }
                }
                finally
                {
                    Marshal.FreeHGlobal(intPtr);
                }
            }
            return $"Unknown error (0x{errorCode:x})";
        }
 
        private static string GetAndTrimString(Span<char> buffer)
        {
            int num = buffer.Length;
            while (num > 0 && buffer[num - 1] <= ' ')
            {
                num--;
            }
            return buffer.Slice(0, num).ToString();
        }
    }
}