自定义编辑框VC,可加载更改字体，添加背景图片，显示输入提示信息

搞了一天终于弄了个完整的编辑框控件出来了，

哎，，，搞界面开发还是有点复杂的。

#pragma once

#include "AdvEdit.h"
// CBkgEditBox

class CBkgEditBox : public CEdit
{
    DECLARE_DYNAMIC(CBkgEditBox)

public:
    CBkgEditBox();
    virtual ~CBkgEditBox();

protected:
    DECLARE_MESSAGE_MAP()
public:
    afx_msg BOOL OnEraseBkgnd(CDC* pDC);
    afx_msg void OnSetFocus(CWnd* pOldWnd);
    afx_msg void OnMouseHover(UINT nFlags, CPoint point);
    afx_msg void OnMouseLeave();
    afx_msg void OnMouseMove(UINT nFlags, CPoint point);
    afx_msg HBRUSH OnCtlColor(CDC* pDC, CWnd* pWnd, UINT nCtlColor);
    afx_msg HBRUSH CtlColor(CDC* pDC, UINT nCtlColor);
    afx_msg void OnChar(UINT nChar, UINT nRepCnt, UINT nFlags);
    afx_msg void OnKillFocus(CWnd* pNewWnd);
    
private:
    BOOL m_bFirstDraw;          // 第一次绘制背景标识 
    Gdiplus::Image *m_pPngBg;   // 背景位图资源
    BOOL m_bHover;              // 鼠标是否在编辑框上标识
    BOOL m_bAllowMouseTrack;    // 鼠标移动时是否允许追踪鼠标移动     
    COLORREF m_clrBkgnd;        // 默认背景Hover颜色
    COLORREF m_clrHoverBkgnd;   // 默认背景UnHover颜色
    COLORREF m_clrText;         // 字体颜色
    CString  m_strTipStr;       // 输入提示信息
    CBrush   m_brhNull;         // 空画刷对象
    CFont*   m_pTextFont;       // 编辑框字体
    
public:
    BOOL SetBackgndRes( UINT nResourceID, LPCTSTR lpszType=_T("PNG"));
    void SetGrayTipString(LPCTSTR lpszTipString);
    void SetTextColor(COLORREF clrText);
    BOOL SetTextFont(int nHeight = 18, int nWidth = 10, LPCTSTR lpszFaceName = _T("宋体"));
  BOOL IsEditEmpty();
};

// MyEditBox.cpp : 实现文件
//

#include "stdafx.h"
#include "BkgEditBox.h"


// CBkgEditBox

IMPLEMENT_DYNAMIC(CBkgEditBox, CEdit)

CBkgEditBox::CBkgEditBox()
{
    m_bFirstDraw = TRUE;
    m_pPngBg     = NULL;
    m_bHover     = FALSE;
    m_bAllowMouseTrack = TRUE;

    m_clrBkgnd      = RGB(255,255,255);
    m_clrHoverBkgnd = RGB(255,255,255);
    m_clrText       = RGB(0,0,0);
    m_strTipStr = _T("");

    m_brhNull.CreateStockObject(NULL_BRUSH);
    m_pTextFont = NULL;
}

CBkgEditBox::~CBkgEditBox()
{
    if (NULL != m_pTextFont)
    {
        delete m_pTextFont;
        m_pTextFont = NULL;
    }
}


BEGIN_MESSAGE_MAP(CBkgEditBox, CEdit)
    ON_WM_ERASEBKGND()
    ON_WM_SETFOCUS()
    ON_WM_MOUSEHOVER()
    ON_WM_MOUSELEAVE()
    ON_WM_MOUSEMOVE()
    ON_WM_CTLCOLOR()
    ON_WM_CTLCOLOR_REFLECT()
    ON_WM_CHAR()
    ON_WM_KILLFOCUS()
END_MESSAGE_MAP()



// CBkgEditBox 消息处理程序




BOOL CBkgEditBox::OnEraseBkgnd(CDC* pDC)
{
    // 图片背景与编辑框的距离顶点
    int nLeftStep,nTopStep,nWidthStep,nHeightStep;
    nLeftStep = 1;
    nTopStep  = 5;
    nWidthStep  = 2;
    nHeightStep = 8;
    CDC* pOldDC = pDC;
    if (NULL != m_pPngBg)
    {
        pDC = GetParent()->GetDC();
        CRect rect;
        GetWindowRect(&rect);
        this->GetParent()->ScreenToClient(&rect);

        int nWidth  = m_pPngBg->GetWidth();
        int nHeight = m_pPngBg->GetHeight();

        // 不是第一次绘制时需要调整位置
        if (!m_bFirstDraw)
        {
            rect.left -= nLeftStep;
            rect.top  -= nTopStep;
        }else
        {
            MoveWindow(rect.left + nLeftStep, rect.top + nTopStep,
                nWidth - nWidthStep, nHeight - nHeightStep);
        }


        CDC MemDc;
        MemDc.CreateCompatibleDC(pDC);

        CBitmap bitMemMap;
        bitMemMap.CreateCompatibleBitmap(pDC, nWidth, nHeight);
        MemDc.SelectObject(&bitMemMap);

        Gdiplus::Graphics graphics(MemDc.m_hDC);
        graphics.DrawImage(m_pPngBg, 0, 0, nWidth, nHeight);
        pDC->BitBlt(rect.left, rect.top, nWidth,nHeight, &MemDc, 0, 0,SRCCOPY);
    
        bitMemMap.DeleteObject();
        MemDc.DeleteDC(); 
        m_bFirstDraw = FALSE;

        pDC = pOldDC;
    }


    
    {
    
        // 内阴影
        CBrush brhInnerShadow;
        if (!m_bHover)
        {
            brhInnerShadow.CreateSolidBrush(m_clrBkgnd);
        }else
        {
            brhInnerShadow.CreateSolidBrush(m_clrHoverBkgnd);
        }
        

        CBrush* pOldBrh = pDC->SelectObject(&brhInnerShadow);
        pDC->SelectStockObject(NULL_PEN);
        CRect rcShadow;
        GetClientRect(&rcShadow);
        if (NULL != m_pPngBg)
        {
            rcShadow.right  = rcShadow.left + m_pPngBg->GetWidth() - nWidthStep;
            rcShadow.bottom = rcShadow.top + m_pPngBg->GetHeight() - nHeightStep;
        }
        pDC->Rectangle(&rcShadow);
        if(NULL!=pOldBrh)
        {
            pDC->SelectObject(pOldBrh);
        }
        brhInnerShadow.DeleteObject();
        this->UpdateWindow();

    }

    return CEdit::OnEraseBkgnd(pDC);
}

BOOL CBkgEditBox::SetBackgndRes( UINT nResourceID, LPCTSTR lpszType/*=_T("PNG")*/ )
{
    return G_ImageFromIDResource(nResourceID, lpszType, m_pPngBg);
}


void CBkgEditBox::OnMouseHover(UINT nFlags, CPoint point)
{
    m_bHover = TRUE;
    Invalidate();

    CEdit::OnMouseHover(nFlags, point);
}


void CBkgEditBox::OnMouseLeave()
{
    // Hover结束
    m_bHover = FALSE;
    // 重绘背景
    Invalidate();

    // 鼠标离开，继续追踪HOVER消息
    m_bAllowMouseTrack = TRUE;

    //CWnd* pWnd =this->GetParent();

    //CRect rcTmp;
    //GetClientRect(rcTmp);
    //rcTmp.OffsetRect(3, 3);
    ////InvalidateRect(rcTmp);
    //this->ClientToScreen(&rcTmp);
    //pWnd->ScreenToClient(&rcTmp);
    //pWnd->InvalidateRect(&rcTmp);
    //pWnd->UpdateWindow();



    CEdit::OnMouseLeave();
}


void CBkgEditBox::OnMouseMove(UINT nFlags, CPoint point)
{
    // 默认情况下，窗口是不响应 WM_MOUSELEAVE 和 WM_MOUSEHOVER 消息的，
    // 所以要使用 _TrackMouseEvent 函数来激活这两个消息
    // https://msdn.microsoft.com/en-us/library/ms645604

    if (m_bAllowMouseTrack)
    {
        TRACKMOUSEEVENT tme;
        tme.cbSize      = sizeof(TRACKMOUSEEVENT);
        tme.dwFlags     = TME_HOVER|TME_LEAVE;
        tme.hwndTrack   = m_hWnd;
        tme.dwHoverTime = 10; // 超过10ms才会认为HOVER

        _TrackMouseEvent(&tme);
        m_bAllowMouseTrack = FALSE;
    }

    CEdit::OnMouseMove(nFlags, point);
}

BOOL CBkgEditBox::IsEditEmpty()
{
    CString strText;
    GetWindowText(strText);
    if (strText.IsEmpty())
    {
        return TRUE;
    }
    if (strText == m_strTipStr)
    {
        return TRUE;
    }
    return FALSE;
}


HBRUSH CBkgEditBox::OnCtlColor(CDC* pDC, CWnd* pWnd, UINT nCtlColor)
{
    HBRUSH hbr = CEdit::OnCtlColor(pDC, pWnd, nCtlColor);

    // TODO:  在此更改 DC 的任何特性

    // TODO:  如果默认的不是所需画笔，则返回另一个画笔
    
    return hbr;
}

HBRUSH CBkgEditBox::CtlColor( CDC* pDC, UINT nCtlColor )
{
    // 设置透明背景
    pDC->SetBkMode(TRANSPARENT);
    
    CString sText;
    GetWindowText(sText);
    if (sText == m_strTipStr)
    {
        pDC->SetTextColor(RGB(150,150,150));
    }else
    {
        pDC->SetTextColor(m_clrText);
    }

    return m_brhNull;
}


void CBkgEditBox::OnChar(UINT nChar, UINT nRepCnt, UINT nFlags)
{
    Invalidate(TRUE);

    CEdit::OnChar(nChar, nRepCnt, nFlags);
}


void CBkgEditBox::OnSetFocus(CWnd* pOldWnd)
{
    CEdit::OnSetFocus(pOldWnd);
    
    CString sText;
    GetWindowText(sText);
    if (sText == m_strTipStr)
    {
        SetWindowText(_T(""));
    }
    Invalidate(TRUE);
    return ;
    
}
void CBkgEditBox::OnKillFocus(CWnd* pNewWnd)
{
    CEdit::OnKillFocus(pNewWnd);

    CString sText;
    GetWindowText(sText);
    if (_T("") == sText)
    {
        SetWindowText(m_strTipStr);
    }
}

void CBkgEditBox::SetGrayTipString( LPCTSTR lpszTipString )
{
    m_strTipStr = lpszTipString;

    SetWindowText(lpszTipString);
}

void CBkgEditBox::SetTextColor( COLORREF clrText )
{
    m_clrText = m_clrText;
}

// https://msdn.microsoft.com/zh-tw/library/vstudio/2ek64h34.aspx
BOOL CBkgEditBox::SetTextFont( int nHeight /*= 20*/, int nWidth /*= 12*/, LPCTSTR lpszFaceName /*= _T("宋体")*/ )
{
    if (NULL != m_pTextFont)
    {
        delete m_pTextFont;
        m_pTextFont = NULL;
    }
    m_pTextFont = new CFont;
    m_pTextFont->CreateFont(
        nHeight,                   // nHeight
        nWidth,                    // nWidth
        0,                         // nEscapement
        0,                         // nOrientation
        FW_NORMAL,                 // nWeight
        FALSE,                     // bItalic
        FALSE,                     // bUnderline
        0,                         // cStrikeOut
        ANSI_CHARSET,              // nCharSet
        OUT_DEFAULT_PRECIS,        // nOutPrecision
        CLIP_DEFAULT_PRECIS,       // nClipPrecision
        DEFAULT_QUALITY,           // nQuality
        DEFAULT_PITCH | FF_SWISS,  // nPitchAndFamily
        lpszFaceName);

    this->SetFont(m_pTextFont);
    return TRUE;
}