创建了一个 ATL COM 项目,通过它我将菜单项插入到右键菜单中,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 );
}
现在我想在用户单击Connect子菜单时立即禁用它,为此我使用 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;
.....
....
...
}
但这对禁用菜单项没有帮助。我做错了什么??
最佳答案
试试这个:
EnableMenuItem(gHMenu,ITEM_ID,MF_DISABLED | MF_GRAYED);
ITEM_ID
应该是菜单项的资源 ID。
或者:
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,调用 EnableMenuItem
后,您可能需要调用 DrawMenuBar
以确保显示已更新。
关于c++ - EnableMenuItem 函数无法使用参数 MF_GRAYED,我们在Stack Overflow上找到一个类似的问题: https://stackoverflow.com/questions/3776272/