MFC中Control在浮动窗口中disable的解决方法

you put the event handler in CMainFrame. What I did is I add the event handler in CPaneDialog, which is a sub window of the CMainFrame, how about try the following steps?

1. Drag a button on the IDD_DLG_BAR

2. Double click the button and VS will prompt to create a class  for that dialog, choose CDialog because VS class wizard don't allow to derive from CPaneDialog directly.

3. After the new class was created, change the CDialog to CPaneDialog
4. Add a event handler for the button in the new class 
The button is still disabled

5.if add an ON_UPDATE_COMMAND_UI handler for the button, it is enabled.

其中第五步的代码：

afx_msg void OnUpdateMyControl(CCmdUI* pCmdUI);  

BEGIN_MESSAGE_MAP(CDockBotton, CDockablePane)

：

ON_UPDATE_COMMAND_UI(IDC_BUTTON_SCANPure, OnUpdateMyControl) 

：

END_MESSAGE_MAP()

void CDockBotton::OnUpdateMyControl(CCmdUI* pCmdUI)
{
pCmdUI->Enable(TRUE);
}