可以使用DisplayContextMenu表单JEDI JCL库显示多个文件的Windows上下文菜单吗？

Question

可以使用DisplayContextMenu表单JEDI JCL library显示多个文件的Windows上下文菜单吗？

这是代码：

function DisplayContextMenu(const Handle: THandle; const FileName: string;
  Pos: TPoint): Boolean;
var
  ItemIdList: PItemIdList;
  Folder: IShellFolder;
begin
  Result := False;
  ItemIdList := PathToPidlBind(FileName, Folder);
  if ItemIdList <> nil then
  begin
    Result := DisplayContextMenuPidl(Handle, Folder, ItemIdList, Pos);
    PidlFree(ItemIdList);
  end;
end;

function DisplayContextMenuPidl(const Handle: THandle; const Folder: IShellFolder;
  Item: PItemIdList; Pos: TPoint): Boolean;
var
  Cmd: Cardinal;
  ContextMenu: IContextMenu;
  ContextMenu2: IContextMenu2;
  Menu: HMENU;
  CommandInfo: TCMInvokeCommandInfo;
  CallbackWindow: THandle;
begin
  Result := False;
  if (Item = nil) or (Folder = nil) then
    Exit;
  Folder.GetUIObjectOf(Handle, 1, Item, IID_IContextMenu, nil,
    Pointer(ContextMenu));
  if ContextMenu <> nil then
  begin
    Menu := CreatePopupMenu;
    if Menu <> 0 then
    begin
      if Succeeded(ContextMenu.QueryContextMenu(Menu, 0, 1, $7FFF, CMF_EXPLORE)) then
      begin
        CallbackWindow := 0;
        if Succeeded(ContextMenu.QueryInterface(IContextMenu2, ContextMenu2)) then
        begin
          CallbackWindow := CreateMenuCallbackWnd(ContextMenu2);
        end;
        ClientToScreen(Handle, Pos);
        Cmd := Cardinal(TrackPopupMenu(Menu, TPM_LEFTALIGN or TPM_LEFTBUTTON or
          TPM_RIGHTBUTTON or TPM_RETURNCMD, Pos.X, Pos.Y, 0, CallbackWindow, nil));
        if Cmd <> 0 then
        begin
          ResetMemory(CommandInfo, SizeOf(CommandInfo));
          CommandInfo.cbSize := SizeOf(TCMInvokeCommandInfo);
          CommandInfo.hwnd := Handle;
          CommandInfo.lpVerb := MakeIntResourceA(Cmd - 1);
          CommandInfo.nShow := SW_SHOWNORMAL;
          Result := Succeeded(ContextMenu.InvokeCommand(CommandInfo));
        end;
        if CallbackWindow <> 0 then
          DestroyWindow(CallbackWindow);
      end;
      DestroyMenu(Menu);
    end;
  end;
end;

Answer 1

要显示多个项目的上下文菜单，您必须稍微修改一下代码。

首先，您必须分配一个PItemIDList数组并填充数组的每个元素，最后将GetUIObjectOf方法传递给具有元素数量的数组。

试试这个样本

uses
  JclShell,
  ShlObj;

function MenuCallback(Wnd: THandle; Msg: UINT; wParam: WPARAM; lParam: LPARAM): LRESULT; stdcall;
var
  ContextMenu2: IContextMenu2;
begin
  case Msg of
    WM_CREATE:
      begin
        ContextMenu2 := IContextMenu2(PCreateStruct(lParam).lpCreateParams);
        SetWindowLongPtr(Wnd, GWLP_USERDATA, LONG_PTR(ContextMenu2));
        Result := DefWindowProc(Wnd, Msg, wParam, lParam);
      end;
    WM_INITMENUPOPUP:
      begin
        ContextMenu2 := IContextMenu2(GetWindowLongPtr(Wnd, GWLP_USERDATA));
        ContextMenu2.HandleMenuMsg(Msg, wParam, lParam);
        Result := 0;
      end;
    WM_DRAWITEM, WM_MEASUREITEM:
      begin
        ContextMenu2 := IContextMenu2(GetWindowLongPtr(Wnd, GWLP_USERDATA));
        ContextMenu2.HandleMenuMsg(Msg, wParam, lParam);
        Result := 1;
      end;
  else
    Result := DefWindowProc(Wnd, Msg, wParam, lParam);
  end;
end;

function CreateMenuCallbackWnd(const ContextMenu: IContextMenu2): THandle;
const
  IcmCallbackWnd = 'ICMCALLBACKWND';
var
  WndClass: TWndClass;
begin
  ZeroMemory(@WndClass, SizeOf(WndClass));
  WndClass.lpszClassName := PChar(IcmCallbackWnd);
  WndClass.lpfnWndProc := @MenuCallback;
  WndClass.hInstance := HInstance;
  Winapi.Windows.RegisterClass(WndClass);
  Result := CreateWindow(IcmCallbackWnd, IcmCallbackWnd, WS_POPUPWINDOW, 0,
    0, 0, 0, 0, 0, HInstance, Pointer(ContextMenu));
end;

type
  PArrayOfPItemIDList = ^TArrayOfPItemIDList;
  TArrayOfPItemIDList = array[0..0] of PItemIDList;

function DisplayContextMenuPidl(const Handle: THandle; const Folder: IShellFolder;
  Item: PArrayOfPItemIDList; ItemsCount :Integer; Pos: TPoint): Boolean;
var
  Cmd: Cardinal;
  ContextMenu: IContextMenu;
  ContextMenu2: IContextMenu2;
  Menu: HMENU;
  CommandInfo: TCMInvokeCommandInfo;
  CallbackWindow: THandle;
begin
  Result := False;
  if (Item = nil) or (Folder = nil) then
    Exit;
  //pass the number of elements oif the array (ItemsCount)
  Folder.GetUIObjectOf(Handle, ItemsCount, Item[0], IID_IContextMenu, nil,
    Pointer(ContextMenu));
  if ContextMenu <> nil then
  begin
    Menu := CreatePopupMenu;
    if Menu <> 0 then
    begin
      if Succeeded(ContextMenu.QueryContextMenu(Menu, 0, 1, $7FFF, CMF_EXPLORE)) then
      begin
        CallbackWindow := 0;
        if Succeeded(ContextMenu.QueryInterface(IContextMenu2, ContextMenu2)) then
        begin
          CallbackWindow := CreateMenuCallbackWnd(ContextMenu2);
        end;
        ClientToScreen(Handle, Pos);
        Cmd := Cardinal(TrackPopupMenu(Menu, TPM_LEFTALIGN or TPM_LEFTBUTTON or
          TPM_RIGHTBUTTON or TPM_RETURNCMD, Pos.X, Pos.Y, 0, CallbackWindow, nil));
        if Cmd <> 0 then
        begin
          ZeroMemory(@CommandInfo, SizeOf(CommandInfo));
          CommandInfo.cbSize := SizeOf(TCMInvokeCommandInfo);
          CommandInfo.hwnd := Handle;
          CommandInfo.lpVerb := MakeIntResourceA(Cmd - 1);
          CommandInfo.nShow := SW_SHOWNORMAL;
          Result := Succeeded(ContextMenu.InvokeCommand(CommandInfo));
        end;
        if CallbackWindow <> 0 then
          DestroyWindow(CallbackWindow);
      end;
      DestroyMenu(Menu);
    end;
  end;
end;

function DisplayContextMenu(const Handle: THandle; const  FileNames: array of string;  Pos: TPoint): Boolean;
var
  ItemIdList: PArrayOfPItemIDList;
  Folder: IShellFolder;
  ItemsCount : integer;

  procedure AllocItems;
  var
    i : integer;
  begin
    for i := 0 to  ItemsCount- 1 do
      ItemIdList[i] := PathToPidlBind(FileNames[i], Folder);
  end;

  procedure ReleaseItems;
  var
    i : integer;
  begin
    for i := 0 to  ItemsCount- 1 do
      PidlFree(ItemIdList[i]);
  end;

begin
  Result := False;
  ItemsCount := Length(FileNames);
  if ItemsCount>0 then
  begin
    //Allocate the array
    ItemIdList := AllocMem(SizeOf(PItemIDList) * ItemsCount);
    try
       AllocItems; //fill each item 
      try
        Result := DisplayContextMenuPidl(Handle, Folder, ItemIdList, ItemsCount, Pos);
      finally
        ReleaseItems; //release the items 
      end;
    finally
       FreeMem(ItemIdList); //release the array
    end;
  end;
end;

并使用如此

 DisplayContextMenu(Handle, ['C:\Foo\Bar.txt', 'C:\Foo\Bar2.txt'], Point(0, 0));