How To Trap Arrow Keys in an Edit Control of a Dialog Box (104637)

MORE INFORMATION

1. Create a dialog box class derived from CDialog. For example, you can create a dialog box class called CMyDlg:public CDialog with Class Wizard.
2. Create your own edit class and trap WM_GETDLGCODE and WM_KEYDOWN. The code will resemble the following:

         class CMyEdit : public CEdit
         {
         // Construction
         public:
              CMyEdit();
   
         public:
              virtual ~CMyEdit();
         protected:
              afx_msg UINT OnGetDlgCode();
              afx_msg void OnKeyDown(UINT nChar, UINT nRepCnt, UINT nFlags);
              DECLARE_MESSAGE_MAP()
         };
   
         CMyEdit::CMyEdit()
         {
         }
   
         CMyEdit::~CMyEdit()
         {
         }
   
         BEGIN_MESSAGE_MAP(CMyEdit, CEdit)
              ON_WM_GETDLGCODE()
              ON_WM_KEYDOWN()
         END_MESSAGE_MAP()
   
         UINT CMyEdit::OnGetDlgCode()
         {
   
              return DLGC_WANTARROWS|DLGC_WANTALLKEYS|DLGC_WANTCHARS;
         }
   
         void CMyEdit::OnKeyDown(UINT nChar, UINT nRepCnt, UINT nFlags)
        {
              //Check if the key pressed was a DOWN ARROW key
              if (nChar == VK_DOWN)
                   AfxMessageBox("It is a down arrow key!");
              if (nChar == VK_RIGHT)
                   AfxMessageBox("It is a right arrow key!");
              if (nChar == VK_LEFT)
                   AfxMessageBox("It is a left arrow key!");
              if (nChar == VK_UP)
                   AfxMessageBox("It is a up arrow key!");
              CEdit::OnKeyDown(nChar, nRepCnt, nFlags);
         }
   						

   NOTE: if Class Wizard is used to add a CMyEdit class, you must derive the class from CWnd first and then manually change any references of CWnd to CEdit in the code. It is important to trap WM_GEDLGCODE in your own edit class and specify DLGC_WANTARROWS in OnGetDlgCode().
3. Create a member variable that maps to your own edit class in the dialog box class and override CWnd::DoDataExchange(). Your code should resemble the following:

         class CMyDlg : public CDialog
         {
         public:
              CMyEdit m_edit;
         protected:
              virtual void DoDataExchange(CDataExchange* pDX); //DDX/DDV
   
              DECLARE_MESSAGE_MAP()
         };
         void CMyDlg::DoDataExchange(CDataExchange* pDX)
         {
              CDialog::DoDataExchange(pDX);
              DDX_Control(pDX, IDC_EDIT1, m_edit);
         }
   						

   NOTE: This can be done easily by Class Wizard. For example, you can add a member variable m_edit and map it to CEdit and then manually change CEdit references in MyEdit.CPP and MyEdit.H files to CMyEdit.