我想找出特定驱动器盘符的 Drive-GUID。 我有以下代码:
Function GetVolumeNameForVolumeMountPoint(lpszVolumeMountPoint: LPCTSTR; lpszVolumeName: LPTSTR; cchBufferLength: DWORD): BOOL; stdcall;
external 'kernel32.dll' name 'GetVolumeNameForVolumeMountPointW';
procedure TForm1.Button1Click(Sender: TObject);
var
Buffer: array[0..50] of AnsiChar;
begin
if GetVolumeNameForVolumeMountPoint('C:\', Buffer, SizeOf(Buffer)) then
begin
showmessage(buffer); // Expected: "\\?\Volume{deadbeef-895e-4a1d-9d64-9b82fa068d76}\"
end
else RaiseLastOSError; // Actual: ERROR_INVALID_NAME (123).
end;
我收到错误 ERROR_INVALID_NAME (123)
,但我不知道为什么。我做错了什么?
最佳答案
您正在调用该函数的 Unicode 版本,但传递的是 ANSI 文本。因此,您传递的第一个参数编码错误,因此出现错误消息。
这个程序演示了它应该如何完成:
{$APPTYPE CONSOLE}
uses
SysUtils, Windows;
function GetVolumeNameForVolumeMountPointA(lpszVolumeMountPoint: PAnsiChar;
lpszVolumeName: PAnsiChar; cchBufferLength: DWORD): BOOL; stdcall;
external 'kernel32.dll';
procedure Main;
var
Buffer: array [0 .. 49] of AnsiChar;
begin
Win32Check(GetVolumeNameForVolumeMountPointA('C:\', Buffer, Length(Buffer)));
Writeln(Buffer);
end;
begin
try
Main;
except
on E: Exception do
Writeln(E.ClassName, ': ', E.Message);
end;
Readln;
end.
因为很明显您使用的是 Delphi 的 pre-Unicode 版本(否则您的程序将无法编译),我在上面给了您 ANSI 代码。如果您曾经升级到 Unicode 版本的 Delphi,那么您应该这样写:
{$APPTYPE CONSOLE}
uses
SysUtils, Windows;
function GetVolumeNameForVolumeMountPointW(lpszVolumeMountPoint: PWideChar;
lpszVolumeName: PWideChar; cchBufferLength: DWORD): BOOL; stdcall;
external 'kernel32.dll';
procedure Main;
var
Buffer: array [0 .. 49] of WideChar;
begin
Win32Check(GetVolumeNameForVolumeMountPointW('C:\', Buffer, Length(Buffer)));
Writeln(Buffer);
end;
begin
try
Main;
except
on E: Exception do
Writeln(E.ClassName, ': ', E.Message);
end;
Readln;
end.
或者如果您想要在所有版本的 Delphi 中工作的代码,您可以这样做:
{$APPTYPE CONSOLE}
uses
SysUtils, Windows;
const
Win32ImportSuffix = {$IFDEF Unicode}'W'{$ELSE}'A'{$ENDIF};
function GetVolumeNameForVolumeMountPointA(lpszVolumeMountPoint: PAnsiChar;
lpszVolumeName: PAnsiChar; cchBufferLength: DWORD): BOOL; stdcall;
external 'kernel32.dll';
function GetVolumeNameForVolumeMountPointW(lpszVolumeMountPoint: PWideChar;
lpszVolumeName: PWideChar; cchBufferLength: DWORD): BOOL; stdcall;
external 'kernel32.dll';
function GetVolumeNameForVolumeMountPoint(lpszVolumeMountPoint: PChar;
lpszVolumeName: PChar; cchBufferLength: DWORD): BOOL; stdcall;
external 'kernel32.dll' name 'GetVolumeNameForVolumeMountPoint' + Win32ImportSuffix;
procedure Main;
var
Buffer: array [0 .. 49] of Char;
begin
Win32Check(GetVolumeNameForVolumeMountPoint('C:\', Buffer, Length(Buffer)));
Writeln(Buffer);
end;
begin
try
Main;
except
on E: Exception do
Writeln(E.ClassName, ': ', E.Message);
end;
Readln;
end.
关于windows - 获取特定驱动器的 GUID,我们在Stack Overflow上找到一个类似的问题: https://stackoverflow.com/questions/38121438/