In Windows Explorer, you right click on a file, a context menu shows up which contains built-in items like 'Send to...' and/or 3rd party actions such as 'zip file with Winzip'. My question are:
Thank you in advance!
[EDIT]: While other info is absolutely useful, Delphi solution will be much appreciated!
The key to obtain the Shell Context menu is use the IContextMenu interface.
check this great article Shell context menu support for more details.
UPDATE
for delphi examples you can see the JclShell unit from the JEDI JCL (check the DisplayContextMenu function) and the ShellCtrls unit included in the samples folder of Delphi.
Short answer
Try the ShellBrowser Components from JAM Software. They have a component that will let you show Explorer's context menu with your own commands mixed in from a TPopupMenu.
Long answer
Getting the Explorer menu, querying all of its properties, and hosting them in your own menu is possible, but you really should be comfortable reading/writing low-level Win32 code and a working knowledge of C will help. You'll also need to watch out for some gotchas (covered below). I strongly recommend reading Raymond Chen's How to host an IContextMenu series for a lot of the technical details.
The easier approach is to query for the IContextMenu interface, then the HMENU, then use TrackPopupMenu to let have Windows show the menu, then call InvokeCommand at the end.
Some of the code below is untested or has been modified from what we're using, so proceed at your own risk.
Here's how you get the IContextMenu, for a group of files within a base folder:
function GetExplorerMenu(AHandle: HWND; const APath: string;
AFilenames: TStrings): IContextMenu;
var
Desktop, Parent: IShellFolder;
FolderPidl: PItemIDList;
FilePidls: array of PItemIDList;
PathW: WideString;
i: Integer;
begin
// Retrieve the Desktop's IShellFolder interface
OleCheck(SHGetDesktopFolder(Desktop));
// Retrieve the parent folder's PItemIDList and then it's IShellFolder interface
PathW := WideString(IncludeTrailingPathDelimiter(APath));
OleCheck(Desktop.ParseDisplayName(AHandle, nil, PWideChar(PathW),
Cardinal(nil^), FolderPidl, Cardinal(nil^)));
try
OleCheck(Desktop.BindToObject(FolderPidl, nil, IID_IShellFolder, Parent));
finally
SHFree(FolderPidl);
end;
// Retrieve PIDLs for each file, relative the the parent folder
SetLength(FilePidls, AFilenames.Count);
try
FillChar(FilePidls[0], SizeOf(PItemIDList) * AFilenames.Count, 0);
for i := 0 to AFilenames.Count-1 do begin
PathW := WideString(AFilenames[i]);
OleCheck(Parent.ParseDisplayName(AHandle, nil, PWideChar(PathW),
Cardinal(nil^), FilePidls[i], Cardinal(nil^)));
end;
// Get the context menu for the files from the parent's IShellFolder
OleCheck(Parent.GetUIObjectOf(AHandle, AFilenames.Count, FilePidls[0],
IID_IContextMenu, nil, Result));
finally
for i := 0 to Length(FilePidls) - 1 do
SHFree(FilePidls[i]);
end;
end;
To get the actual menu items you need to call IContextMenu.QueryContextMenu. You can destroy the returned HMENU using DestroyMenu.
function GetExplorerHMenu(const AContextMenu: IContextMenu): HMENU;
const
MENUID_FIRST = 1;
MENUID_LAST = $7FFF;
var
OldMode: UINT;
begin
OldMode := SetErrorMode(SEM_FAILCRITICALERRORS or SEM_NOOPENFILEERRORBOX);
try
Result := CreatePopupMenu;
AContextMenu.QueryContextMenu(Result, 0, MENUID_FIRST, MENUID_LAST, CMF_NORMAL);
finally
SetErrorMode(OldMode);
end;
end;
Here's how you actually call the command that the user has selected from the menu:
procedure InvokeCommand(const AContextMenu: IContextMenu; AVerb: PChar);
const
CMIC_MASK_SHIFT_DOWN = $10000000;
CMIC_MASK_CONTROL_DOWN = $20000000;
var
CI: TCMInvokeCommandInfoEx;
begin
FillChar(CI, SizeOf(TCMInvokeCommandInfoEx), 0);
CI.cbSize := SizeOf(TCMInvokeCommandInfo);
CI.hwnd := GetOwnerHandle(Owner);
CI.lpVerb := AVerb;
CI.nShow := SW_SHOWNORMAL;
// Ignore return value for InvokeCommand. Some shell extensions return errors
// from it even if the command worked.
try
AContextMenu.InvokeCommand(PCMInvokeCommandInfo(@CI)^)
except on E: Exception do
MessageDlg(Owner, E.Message, mtError, [mbOk], 0);
end;
end;
procedure InvokeCommand(const AContextMenu: IContextMenu; ACommandID: UINT);
begin
InvokeCommand(AContextMenu, MakeIntResource(Word(ACommandID)));
end;
Now you can use the GetMenuItemInfo function to get the caption, bitmap, etc, but a much easier approach is to call TrackPopupMenu and let Windows show the popup menu. That would look something like this:
procedure ShowExplorerMenu(AForm: TForm; AMousePos: TPoint;
const APath: string; AFilenames: TStrings; );
var
ShellMenu: IContextMenu;
Menu: HMENU;
MenuID: LongInt;
begin
ShellMenu := GetExplorerMenu(AForm.Handle, APath, AFilenames);
Menu := GetExplorerHMenu(ShellMenu);
try
MenuID := TrackPopupMenu(Menu, TPM_LEFTALIGN or TPM_TOPALIGN or TPM_RETURNCMD,
AMousePos.X, AMousePos.Y, 0, AForm.Handle, nil);
InvokeCommand(ShellMenu, MenuID - MENUID_FIRST);
finally
DestroyMenu(Menu);
end;
end;
If you actually want to extract the menu items/captions and add them to your own popup menu (we use Toolbar 2000 and do exactly that), here are the other big issues you'll run into:
