Edit Control with Icon and Background Text

Introduction

This article presents an edit control that can display an icon and a prompt text on the background (when the edit control has no text). This is most suitable to indicate to the users that an edit control is used to input text that is used for a search.

Demystifying Subclassing.")

The image below shows several such edit controls.



The same controls look like the following when text is entered.



Features of the edit control:

Displays an icon on the right side of the control
Displays a prompt text (only when the control has no text)
Changes the color of the prompt text
Changes the font of the prompt text

Implementation

The class implementing this control is called CSymbolEdit and subclasses CEdit. (If you're not familiar with subclassing, a method of customizing the behavior of a window, I suggest you read this article: "

The public interface of the control is:

void SetSymbolIcon(HICON hIcon, BOOL redraw = TRUE);


void SetSymbolIcon(UINT id,     BOOL redraw = TRUE);




void SetPromptText(CString text,   BOOL redraw = TRUE);


void SetPromptText(LPCTSTR szText, BOOL redraw = TRUE);




void SetPromptTextColor(COLORREF color, BOOL redraw = TRUE);




void SetPromptFont(CFont& font,              BOOL redraw = TRUE);


void SetPromptFont(const LOGFONT* lpLogFont, BOOL redraw = TRUE);

There are two overloads for SetSymbolIcon, one that takes an HICON, and one that takes the ID of a resource. The control is responsible for releasing the icon resource only when the second overload was used. If an HICON was passed, the client
of the control must release this resource.

If SetPromptTextColor is not called and a prompt text was set, this prompt text is draw by default with the color RGB(127, 127, 127).

If SetPromptFont is not called and a prompt text was set, this text is drawn with Calibri in italics.

How to Use It in Your Code

In your dialog class header, include "SymbolEdit.h".

Declare a variable of type CSymbolEdit.

CSymbolEdit m_edit;

Map it to the control in DoDataExchange:

void CEditDemoDlg::DoDataExchange(CDataExchange* pDX)
{
    CDialog::DoDataExchange(pDX);
    DDX_Control(pDX, IDC_EDIT, m_edit);
}

Set the icon, text, color, or font (in OnInitDialog, for example).

m_edit.SetSymbolIcon(IDI_SEARCH, FALSE);


m_edit.SetPromptText(_T("Find "), FALSE);


m_edit.SetPromptTextColor(RGB(192, 192, 192));

About the Author

Marius Bancila is a Microsoft MVP for VC++. He works as a software developer for a Norwegian-based company. He is mainly focused on building desktop applications with MFC and VC#. He keeps a blog at www.mariusbancila.ro/blog, focused on Windows programming.
In July 2007 together with two other Romanian MVPs he created codexpert.ro, a community for Romanian C++/VC++ programmers.

Downloads

EditDemo_2005.zip -
demo application in Visual Studio 2005

EditDemo_2008.zip -
demo application in Visual Studio 2008

SymbolEdit.zip - source code
for the edit control

转帖：http://blog.csdn.net/tieshashi/article/details/2306992