如何在MFC中限制文本框中的複製粘貼？

Question

我正在MFC中開發一個小應用程序......有一個小問題..希望你們能夠幫助我解決這個問題...我們現在去......問題是......我有6個小編輯控件（Text框），其中我將允許用戶輸入一些數字..我已經限制字符數/文本框爲4，但它允許用戶複製和粘貼n個數字....如何限制複製粘貼選項編輯控件....請幫我...

Answer 1

我找到解決問題的2種方式....請檢查下面...

第1種方法：

class CNoPasteEdit: public CEdit 
{ 
public: 
CNoPasteEdit(); 
~CNoPasteEdit(); 
protected: 
// This line will need to be added by hand because WM_PASTE is not available in 
// class wizard 
afx_msg void OnPaste(WPARAM wParam, LPARAM lParam); 
afx_msg void OnContextMenu(CWnd* pWnd, CPoint point); 
DECLARE_MESSAGE_MAP() 
}; 

然後，你將需要編輯.cpp文件該類像這樣

CNoPasteEdit::CNoPasteEdit(){ 
// Put any construction code here 
} 

CNoPasteEdit:~:CNoPasteEdit(){ 
// Put any destruction code here 
} 

BEGIN_MESSAGE_MAP(CNoPasteEdit, CEdit) 
// This line is needed because there is no default macro for WM_PASTE messages 
// This line will also need to be added by hand 
ON_MESSAGE(WM_PASTE, OnPaste) 
ON_WM_CONTEXTMENU() 
END_MESSAGE_MAP() 

void CNoPasteEdit::OnPaste(WPARAM wParam, LPARAM lParam){ 
// Put any code here you want to execute when the user right clicks on the edit 
// control. Just leave it blank to disable the menu 
} 

void CNoPasteEdit::OnContextMenu(CWnd* pWnd, CPoint point){ 
// Put any code here you want to execute when the user tries to paste into the edit 
// conrtol. Just leave it blank to prevent pasting. 
} 

第二個方法： 處理好ON_EN_CHANGE事件，並捕捉到CString的文本，並檢查其超過有限的字符..如果它可以清除帶有警告信息的文本框...