delphi - 如何获取USB设备的盘符？

Question

我正在使用 WMI 获取所有插入的 USB 磁盘制造商名称。该代码工作得很好，但我有一个问题，如何确定某个磁盘具有的驱动器号...我只能获取设备名称，例如

(\\.\PhysicalDrive1) ...我如何将其翻译为普通驱动器号？

Answer 1

如果您获得类似 \\.\PHYSICALDRIVE1 的值，则表示您正在使用 Win32_DiskDrive wmi 类和 DeviceID Property ，因此为了获取驱动器盘符您必须使用 ASSOCIATORS 类，它将在包含您正在查找的信息 (Win32_LogicalDisk) 的 wmi 类和您正在使用的类 (Win32_DiskDrive) 之间创建链接。

所以你必须做这样的事情

Win32_DiskDrive-> Win32_DiskDriveToDiskPartition -> Win32_DiskPartition -> Win32_LogicalDiskToPartition -> Win32_LogicalDisk

检查此示例函数

{$APPTYPE CONSOLE}

uses
  SysUtils,
  ActiveX,
  ComObj,
  Variants;


function DeviceIDToDrive(const ADeviceID : string) : string;
var
  FSWbemLocator  : OLEVariant;
  objWMIService  : OLEVariant;
  colLogicalDisks: OLEVariant;
  colPartitions  : OLEVariant;
  objPartition   : OLEVariant;
  objLogicalDisk : OLEVariant;
  oEnumPartition : IEnumvariant;
  oEnumLogical   : IEnumvariant;
  iValue         : LongWord;
  DeviceID       : string;
begin;
  Result:='';
  FSWbemLocator   := CreateOleObject('WbemScripting.SWbemLocator');
  objWMIService   := FSWbemLocator.ConnectServer('localhost', 'root\CIMV2', '', '');
  DeviceID        := StringReplace(ADeviceID,'\','\\',[rfReplaceAll]); //Escape the `\` chars in the DeviceID value because the '\' is a reserved character in WMI.
  colPartitions   := objWMIService.ExecQuery(Format('ASSOCIATORS OF {Win32_DiskDrive.DeviceID="%s"} WHERE AssocClass = Win32_DiskDriveToDiskPartition',[DeviceID]));//link the Win32_DiskDrive class with the Win32_DiskDriveToDiskPartition class
  oEnumPartition  := IUnknown(colPartitions._NewEnum) as IEnumVariant;
  while oEnumPartition.Next(1, objPartition, iValue) = 0 do
   begin
       if not VarIsNull(objPartition.DeviceID) then
       begin
        colLogicalDisks := objWMIService.ExecQuery('ASSOCIATORS OF {Win32_DiskPartition.DeviceID="'+VarToStr(objPartition.DeviceID)+'"} WHERE AssocClass = Win32_LogicalDiskToPartition'); //link the Win32_DiskPartition class with theWin32_LogicalDiskToPartition class.
        oEnumLogical  := IUnknown(colLogicalDisks._NewEnum) as IEnumVariant;
          if oEnumLogical.Next(1, objLogicalDisk, iValue) = 0 then
          begin
              Result:=objLogicalDisk.DeviceID;
              objLogicalDisk:=Unassigned;
          end;
       end;
       objPartition:=Unassigned;
   end;
end;

begin
 try
    CoInitialize(nil);
    try
      Writeln(DeviceIDToDrive('\\.\PHYSICALDRIVE2'));
    finally
      CoUninitialize;
    end;
 except
    on E:Exception do
        Writeln(E.Classname, ':', E.Message);
  end;
  Readln;
end.