delphi 根据盘符弹出U盘

unit Unit1;

interface

uses

Windows, Messages, SysUtils, Variants, Classes, Graphics, Controls, Forms,

Dialogs,EjectUSB, StdCtrls;

// EjectUSB http://www.delphitop.com/html/danyuan/3578.html

type

TForm1 = class(TForm)

Edit1: TEdit;

Button1: TButton;

Button2: TButton;

procedure Button2Click(Sender: TObject);

private

{ Private declarations }

public

{ Public declarations }

end;

var

Form1: TForm1;

implementation

{$R *.dfm}

function SafeRemoveUDisk(DriveLetter: Char; bTips:Boolean):Integer;

var

szDevicePath,

szRootPath,

szVolumeAccessPath: array[0..MAX_PATH-1]of char;

DeviceNumber: Integer ;

hVolume: THANDLE;

sdn: STORAGE_DEVICE_NUMBER;

dwBytesReturned: DWORD;

res: Integer ;

DriveType: UINT;

szDosDeviceName: array[0..MAX_PATH-1]of char;

iDevInst, DevInstParent: DEVINST;

Status: ULONG;

ProblemNumber: ULONG;

VetoType: PNP_VETO_TYPE;

VetoNameW: array[0..MAX_PATH-1]of WCHAR;

bSuccess: bool;

tries: Integer ;

begin

// "X:\" -> for GetDriveType

szRootPath := 'X:\';

szRootPath[0] := DriveLetter;

// "X:" -> for QueryDosDevice

szDevicePath := 'X:';

szDevicePath[0] := DriveLetter;

// "\\.\X:" -> to open the volume

szVolumeAccessPath := '\\.\X:';

szVolumeAccessPath[4] := DriveLetter;

DeviceNumber := -1;

hVolume := CreateFile(szVolumeAccessPath, 0,

FILE_SHARE_READ or FILE_SHARE_WRITE,

nil, OPEN_EXISTING, 0, 0);

if (hVolume = INVALID_HANDLE_VALUE) then

begin

Result := 1;

Exit;

end;

res := Integer(DeviceIoControl(hVolume,

IOCTL_STORAGE_GET_DEVICE_NUMBER,

nil, 0, @sdn, sizeof(sdn),

dwBytesReturned, nil));

if ( res>0 ) then

begin

DeviceNumber := sdn.DeviceNumber;

end;

CloseHandle(hVolume);

if ( DeviceNumber = -1 ) then

begin

Result := 1;

Exit;

end;

DriveType := GetDriveType(szRootPath);

// get the dos device name (like \device\floppy0)

// to decide if it's a floppy or not

res := QueryDosDevice(szDevicePath, szDosDeviceName, MAX_PATH);

if ( res=0 ) then

begin

Result := 1;

Exit;

end;

iDevInst := DeviceNumberDrive(DeviceNumber,

DriveType, szDosDeviceName);

if ( iDevInst=0 ) then

begin

Result := 1;

Exit;

end;

Status := 0;

ProblemNumber := 0;

VetoType := PNP_VetoTypeUnknown;

bSuccess := false;

// get drives's parent, e.g. the USB bridge,

// the SATA port, an IDE channel with two drives!

DevInstParent := 0;

res := CM_Get_Parent(DevInstParent, iDevInst, 0);

for tries:=1 to 3 do

begin

// sometimes we need some tries...

VetoNameW[0] := #0;

if bTips then

res := CM_Request_Device_EjectW(DevInstParent,

@VetoType, nil, 0, 0)

else

res := CM_Request_Device_EjectW(DevInstParent,

@VetoType, VetoNameW, MAX_PATH, 0);

bSuccess := ( res=CR_SUCCESS) and

( VetoType=PNP_VetoTypeUnknown );

if ( bSuccess ) then

begin

break;

end;

Sleep(500); // required to give the next tries a chance!

end;

procedure TForm1.Button2Click(Sender: TObject);

begin

SafeRemoveUDisk('H',True); //H是U盘符,可用edit1来传递U盘符

end;

end.

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