//檢測U盤插入、拔出

測試通過
1、新建工程；
2、定義一個私有過程
procedure WMDeviceChange(var Msg: TMessage); message WM_DEVICECHANGE;

完整代碼如下：
unit Unit1;
interface
uses
   Windows, Messages, SysUtils, Variants, Classes, Graphics, Controls, Forms,
   Dialogs, AppEvnts, ExtCtrls, StdCtrls;
type
    TForm1 = class(TForm)
     procedure Button1Click(Sender: TObject);
  
   private
{ Private declarations }
   procedure WMDeviceChange(var Msg: TMessage); message WM_DEVICECHANGE;
   public
{ Public declarations }
   end;
var
   Form1: TForm1;

implementation
{$R *.dfm}
procedure TForm1.WMDeviceChange (var Msg: TMessage);
var
   myMsg : String;
begin
   Case Msg.WParam of
   32768:
begin
   myMsg :='U盤插入';
   MessageBox(0,'注意!U盤已插入!!!','AutoCopy Information',MB_ICONASTERISK and MB_ICONINFORMATION);
   end;
   32772:
begin
   myMsg :='U盤拔出';
   MessageBox(0,'注意!U盤已取走!!!','AutoCopy Information',MB_ICONASTERISK and MB_ICONINFORMATION);
end;
   end;
end;

===========================================

// 取U盤盤符代碼

使用delphi程序實現(xiàn)U盤盤符的獲取其實不是很難，不過對于新手來說可能有點困難，把代碼貼出來，供大家學習

============================================
procedure TForm1.Button1Click(Sender: TObject);

var
    buf:array [0..MAX_PATH-1] of char;
    m_Result:Integer;
    i:Integer;
    str_temp:string;
begin
m_Result:=GetLogicalDriveStrings(MAX_PATH,buf);
for i:=0 to (m_Result div 4) do
begin
        str_temp:=string(buf[i*4]+buf[i*4+1]+buf[i*4+2]);
         if GetDriveType(pchar(str_temp)) = DRIVE_REMOVABLE then
         begin
            ShowMessage(str_temp+'盤為U盤');
            ListBox1.Items.Add(str_temp);
        end;
end;
end;

=========================================//磁盤類型常量參考

DRIVE_UNKNOWN = 0;
{$EXTERNALSYM DRIVE_UNKNOWN}
DRIVE_NO_ROOT_DIR = 1;
{$EXTERNALSYM DRIVE_NO_ROOT_DIR}
DRIVE_REMOVABLE = 2;
{$EXTERNALSYM DRIVE_REMOVABLE}
DRIVE_FIXED = 3;
{$EXTERNALSYM DRIVE_FIXED}
DRIVE_REMOTE = 4;
{$EXTERNALSYM DRIVE_REMOTE}
DRIVE_CDROM = 5;
{$EXTERNALSYM DRIVE_CDROM}
DRIVE_RAMDISK = 6;