Delphi編程實現清空回收站

本程序演示如何通過程序來清空回收站。

　　向窗體上添加一個TButton組件，它用於激活清空回收站的操作。設計完成的主界面如圖1所示。

<喎?http://www.BkJia.com/kf/ware/vc/" target="_blank" class="keylink">vc3Bhbj48YnIvPg0KICAgICAgICAgICAgzbwxINb3vefD5jwvZGl2Pg0KICAgICAgICAgICAgPC90ZD4NCiAgICAgICAgPC90cj4NCiAgICA8L3Rib2R5Pg0KPC90YWJsZT4NCjxici8+DQqhoaGhytfPyNTas8zQ8rXEaW1wbGVtZW50YXRpb262ztbQtqjS5TO49rOjyv26zdK7uPbA4NDNyfnD96OstPrC68jnz8Kjujxici8+DQo8YnIvPg0KPHRhYmxlIGJvcmRlcmNvbG9yPQ=="#ffcc66" width="90%" align="center" bgcolor="#e3e3e3" border="1"> const

SHERB_NOCONFIRMATION = $00000001 ;

SHERB_NOPROGRESSUI = $00000002 ;

SHERB_NOSOUND = $00000004 ;

type

TSHEmptyRecycleBin=

function(Wnd:HWND;LPCTSTR:PChar;DWORD:Word):Integer;stdcall;
　　程序運行初期，程序首先會通過LoadLibrary函數加載動態鏈接庫Shell32.dll，並且把加載後的操作句柄存儲在LibHandle中。然後通過@SHEmptyRecycleBin:=GetProcAddress (LibHandle, ’SHEmptyRecycleBinA’)語句讀取SHEmptyRecycleBinA函數的地址，如果以上語句能夠正確執行(也就是@SHEmptyRecycleBin不等於nil)，那麼就調用SHEmptyRecycleBin完成清空回收站的操作。最後釋放動態鏈接庫。響應代碼如下：

procedure TForm1.Button1Click(Sender: TObject);
var
　SHEmptyRecycleBin:TSHEmptyRecycleBin;
　LibHandle:THandle;
begin
　LibHandle := LoadLibrary(PChar(’Shell32.dll’)) ;
　if LibHandle <> 0 then
　begin
　　@SHEmptyRecycleBin := GetProcAddress(LibHandle, ’SHEmptyRecycleBinA’);
　end
　else
　begin
　　MessageDlg(’Failed to load Shell32.dll.’, mtError, [mbOK], 0);
　　Exit ;
　end ;
　if @SHEmptyRecycleBin <> nil then
　begin
　　SHEmptyRecycleBin(Application.Handle,’’,SHERB_NOCONFIRMATION or
SHERB_NOPROGRESSUI or SHERB_NOSOUND) ;
　end;
　FreeLibrary(LibHandle);
　@SHEmptyRecycleBin := nil ;
end;
　　程序代碼如下：

unit Unit1;

interface
uses
Windows, Messages, SysUtils, Variants, Classes, Graphics, Controls, Forms,
Dialogs, StdCtrls;

type
　TForm1 = class(TForm)
　Button1: TButton;
　procedure Button1Click(Sender: TObject);
private
　{ Private declarations }
public
　{ Public declarations }
end;

var
　Form1: TForm1;
　implementation
const
　SHERB_NOCONFIRMATION = $00000001 ;
　SHERB_NOPROGRESSUI = $00000002 ;
　SHERB_NOSOUND = $00000004 ;
type
　TSHEmptyRecycleBin=function(Wnd:HWND;LPCTSTR:PChar;DWORD:Word):Integer;stdcall;

　{$R *.dfm}
　procedure TForm1.Button1Click(Sender: TObject);
var
　SHEmptyRecycleBin:TSHEmptyRecycleBin;
　LibHandle:THandle;
begin
　LibHandle := LoadLibrary(PChar(’Shell32.dll’)) ;
　if LibHandle <> 0 then
　begin
　　@SHEmptyRecycleBin := GetProcAddress(LibHandle, ’SHEmptyRecycleBinA’);
　end
　else
　begin
　　MessageDlg(’Failed to load Shell32.dll.’, mtError, [mbOK], 0);
　　Exit ;
　end ;

　if @SHEmptyRecycleBin <> nil then
　begin
　　SHEmptyRecycleBin(Application.Handle,’’,SHERB_NOCONFIRMATION or SHERB_NOPROGRESSUI or SHERB_NOSOUND) ;
　end;
　FreeLibrary(LibHandle);
　@SHEmptyRecycleBin := nil ;
　end;
end.

　　保存文件，然後按F9鍵運行程序，程序運行的初始畫面如圖2所示。

系統回收站中的文件徹底刪除。

　　本程序同時也演示了如何調用一個.dll文件中的函數。