目录选择 API

var
  SelDirInitPath : WideString; // 初始目录，在回调函数中通过发送消息设定

function BrowseCallbackProc(hwnd: HWND;uMsg: UINT;lParam: Cardinal;lpData: Cardinal): integer; stdcall;
begin 
    if uMsg=BFFM_INITIALIZED then
        result :=SendMessageW(Hwnd,BFFM_SETSELECTIONW,Ord(TRUE),longint(PWideChar(SelDirInitPath)))
    else 
        result :=1
end;

function SelDir(h:THandle; const Root: WideString):WideString;
var
    WindowList: Pointer;
    BrowseInfo: TBrowseInfoW;
    Buffer: PWideChar;
    RootItemIDList, ItemIDList: PItemIDList;
    ShellMalloc: IMalloc;
    IDesktopFolder: IShellFolder; 
    Eaten, Flags: LongWord; 
begin 
    Result := '';
    FillChar(BrowseInfo, SizeOf(BrowseInfo), 0); 
    if (ShGetMalloc(ShellMalloc) = S_OK) and (ShellMalloc <> nil) then
    begin
        Buffer := ShellMalloc.Alloc(MAX_PATH);
        try
            RootItemIDList := nil;
            if Root <> '' then begin // 设定目录选择对话框中的顶级目录，默认为桌面
                SHGetDesktopFolder(IDesktopFolder);
                IDesktopFolder.ParseDisplayName(Application.Handle, nil, POleStr(Root), Eaten, RootItemIDList, Flags);
            end;
            with BrowseInfo do begin
                hwndOwner := h;
                pidlRoot := RootItemIDList; 
                pszDisplayName := Buffer; 
                lpszTitle := '选择歌曲所在的目录:';
                ulFlags := BIF_RETURNONLYFSDIRS;
                lpfn :=@BrowseCallbackProc;
                lParam :=BFFM_INITIALIZED;
            end; 
            WindowList := DisableTaskWindows(0); 
            try 
                ItemIDList := ShBrowseForFolderW(BrowseInfo);
            finally
                EnableTaskWindows(WindowList);
            end;
            if ItemIDList <> nil then begin
                ShGetPathFromIDListW(ItemIDList, Buffer);
                ShellMalloc.Free(ItemIDList);
                Result := Buffer;
            end; 
        finally 
            ShellMalloc.Free(Buffer);
        end; 
    end; 
end;
		

int CALLBACK BrowseCallbackProc(HWND hwnd,UINT uMsg,LPARAM lParam,LPARAM lpData)
{
	HWND hh = GetDlgItem(hwnd, lpData);

	switch(uMsg)
	{
	case BFFM_SELCHANGED :
		char path[256];
		SHGetPathFromIDList((LPITEMIDLIST)lParam,path);
		::SetWindowText( GetDlgItem(hwnd, lpData), path);
		return 0;
	default:
		return 0;
	}
}

void SelectDirectory( HWND hwnd, LPCTSTR title, LONG editid)
{

	BROWSEINFO bi;
	char path[MAX_PATH]={"C:\\"};
	bi.hwndOwner =hwnd;
	bi.lpszTitle =title;
	bi.pszDisplayName =path;
	bi.ulFlags =BIF_RETURNONLYFSDIRS;
	bi.lpfn =BrowseCallbackProc;
	bi.pidlRoot =NULL;
	bi.lParam =editid;

	InitCommonControls();
	LPITEMIDLIST a = SHBrowseForFolder(&bi);
	if( a != NULL )
	{
		char path[MAX_PATH];
		SHGetPathFromIDList( a, path);

		::SetWindowText(GetDlgItem(hwnd,editid),path);
	}

}

void CCopyexDlg::OnBTNSource()
{
	SelectDirectory( this->m_hWnd, "Source Directory", IDC_EDIT_Source );
}