CEdit

The CEdit class provides the functionality of a Windows edit control. An edit control is a rectangular child window in which the user can enter text.

You can create an edit control either from a dialog template or directly in your code. In both cases, first call the constructor CEdit to construct the CEdit object, then call the Create member function to create the Windows edit control and attach it to the CEdit object.

Construction can be a one-step process in a class derived from CEdit. Write a constructor for the derived class and call Create from within the constructor.

CEdit inherits significant functionality from CWnd. To set and retrieve text from a CEdit object, use the CWnd member functions SetWindowText and GetWindowText, which set or get the entire contents of an edit control, even if  it is a multiline control.  Also, if an edit control is multiline, get and set part of the control’s text by calling the CEdit member functions GetLine, SetSel, GetSel, and ReplaceSel.

If you want to handle Windows notification messages sent by an edit control to its parent (usually a class derived from CDialog), add a message-map entry and message-handler member function to the parent class for each message.

Each message-map entry takes the following form:

ON_Notification( id, memberFxn )

where id specifies the child window ID of the edit control sending the notification, and memberFxn is the name of the parent member function you have written to handle the notification.

The parent’s function prototype is as follows:

afx_msg void memberFxn( );

Following is a list of potential message-map entries and a description of the cases in which they would be sent to the parent:

• ON_EN_CHANGE   The user has taken an action that may have altered text in an edit control. Unlike the EN_UPDATE notification message, this notification message is sent after Windows updates the display.
  
  
• ON_EN_ERRSPACE   The edit control cannot allocate enough memory to meet a specific request.
  
  
• ON_EN_HSCROLL   The user clicks an edit control’s horizontal scroll bar. The parent window is notified before the screen is updated.
  
  
• ON_EN_KILLFOCUS   The edit control loses the input focus.
  
  
• ON_EN_MAXTEXT   The current insertion has exceeded the specified number of characters for the edit control and has been truncated. Also sent when an edit control does not have the ES_AUTOHSCROLL style and the number of characters to be inserted would exceed the width of the edit control. Also sent when an edit control does not have the ES_AUTOVSCROLL style and the total number of lines resulting from a text insertion would exceed the height of the edit control.
  
  
• ON_EN_SETFOCUS   Sent when an edit control receives the input focus.
  
  
• ON_EN_UPDATE   The edit control is about to display altered text. Sent after the control has formatted the text but before it screens the text so that the window size can be altered, if necessary.
  
  
• ON_EN_VSCROLL   The user clicks an edit control’s vertical scroll bar. The parent window is notified before the screen is updated.

If you create a CEdit object within a dialog box, the CEdit object is automatically destroyed when the user closes the dialog box.

If you create a CEdit object from a dialog resource using the dialog editor, the CEdit object is automatically destroyed when the user closes the dialog box.

If you create a CEdit object within a window, you may also need to destroy it. If you create the CEdit object on the stack, it is destroyed automatically. If you create the CEdit object on the heap by using the new function, you must call delete on the object to destroy it when the user terminates the Windows edit control. If you allocate any memory in the CEdit object, override the CEdit destructor to dispose of the allocations.

For more information on CEdit, see Control Topics in Visual C++ Programmer's Guide.

#include <afxwin.h>

Class Members |  Base Class |  Hierarchy Chart

Samples   MFC Sample CALCDRIV |  MFC Sample CMNCTRL2 |  MFC Sample VCTERM

See Also   CWnd, CButton, CComboBox, CListBox, CScrollBar, CStatic, CDialog