创建了一个ATL COM项目,通过该项目我将菜单项插入右键菜单,如下所示:
STDMETHODIMP CSimpleShlExt::QueryContextMenu (
HMENU hmenu, UINT uMenuIndex, UINT uidFirstCmd,
UINT uidLastCmd, UINT uFlags )
{
gHMenu=hmenu;
UINT uCmdID = uidFirstCmd;
// If the flags include CMF_DEFAULTONLY then we shouldn't do anything.
if ( uFlags & CMF_DEFAULTONLY )
return MAKE_HRESULT ( SEVERITY_SUCCESS, FACILITY_NULL, 0 );
InsertMenu ( hmenu, uMenuIndex, MF_BYPOSITION, uCmdID++, _T("Connect To Server") );
uMenuIndex++;
InsertMenu ( hmenu, uMenuIndex, MF_BYPOSITION, uCmdID++,
_T("DisConnect From Server") );
return MAKE_HRESULT ( SEVERITY_SUCCESS, FACILITY_NULL, 2 );
}
现在我想在用户点击它时立即禁用Connect子菜单,为此我使用的是EnableSubMenuItem,
STDMETHODIMP CSimpleShlExt::InvokeCommand ( LPCMINVOKECOMMANDINFO pCmdInfo )
{
// If lpVerb really points to a string, ignore this function call and bail out.
if ( 0 != HIWORD( pCmdInfo->lpVerb ) )
return E_INVALIDARG;
switch ( LOWORD( pCmdInfo->lpVerb) )
{
case 0:
{
TCHAR szMsg [MAX_PATH + 32];
wsprintf ( szMsg, _T("The selected file was:\n\n%s"), m_szFile );
MessageBox ( pCmdInfo->hwnd, "Connected", _T("SimpleShlExt"),
MB_ICONINFORMATION );
//InsertMenu ( hmenu, uMenuIndex, MF_STRING | MF_BYPOSITION, uCmdID++, _T("Connect => NDS") );
//EnableMenuItem(gHMenu,0,MF_GRAYED);
编辑:
EnableMenuItem(gHMenu,0,MF_DISABLED | MF_GRAYED | MF_BYPOSITION);
return S_OK;
}
break;
.....
....
...
}
但这无助于禁用菜单项。我究竟做错了什么??
试试这个:
EnableMenuItem(gHMenu,ITEM_ID,MF_DISABLED | MF_GRAYED);
ITEM_ID
应该是菜单项的资源ID。
要么:
EnableMenuItem(gHMenu,ITEM_POSITION,MF_DISABLED | MF_GRAYED | MF_BYPOSITION);
其中ITEM_POSITION
是菜单项的零索引位置。
请注意,在调用EnableMenuItem
之后,您可能需要调用DrawMenuBar
以确保显示已更新。