自繪ComboBox(帶圖標)，繪combobox帶圖標

自繪ComboBox(帶圖標)，繪combobox帶圖標

先看看效果

頭文件：

#pragma once
#include <atlimage.h>

// CAddressComboBox

class CAddressComboBox : public CComboBox
{
    DECLARE_DYNAMIC(CAddressComboBox)

public:
    CAddressComboBox();
    virtual ~CAddressComboBox();

protected:
    DECLARE_MESSAGE_MAP()
    afx_msg void OnSize(UINT nType, int cx, int cy);
    afx_msg int OnCreate(LPCREATESTRUCT lpCreateStruct);
    afx_msg void OnPaint();
    afx_msg void OnMouseMove(UINT nFlags, CPoint point);
    afx_msg LRESULT OnMouseHover(WPARAM wParam, LPARAM lParam);
    afx_msg LRESULT OnMouseLeave(WPARAM wParam, LPARAM lParam);
    afx_msg void OnCbnSelchange();

public:
    virtual void DrawItem(LPDRAWITEMSTRUCT /*lpDrawItemStruct*/);
    virtual void MeasureItem(LPMEASUREITEMSTRUCT /*lpMeasureItemStruct*/);

public:
    int AddString(LPCTSTR lpszString, HICON hIcon);

private:
    CImage m_imgComboBox;
    CImage m_imgComboBoxThump;
    CImage m_imgMinClose;
    BOOL m_bIsThumpHover;
    BOOL m_bIsThumpDown;
    CListBox* m_pListBox;
    HICON m_hIcon;
};

源文件：

// AddressComboBox.cpp : 實現文件
//

#include "stdafx.h"
#include "Frame.h"
#include "AddressComboBox.h"
#include "resource.h"


// CAddressComboBox

IMPLEMENT_DYNAMIC(CAddressComboBox, CComboBox)

CAddressComboBox::CAddressComboBox()
{
    m_bIsThumpHover = FALSE;
    m_bIsThumpDown = FALSE;
}

CAddressComboBox::~CAddressComboBox()
{
}


BEGIN_MESSAGE_MAP(CAddressComboBox, CComboBox)
    ON_WM_SIZE()
    ON_WM_CREATE()
    ON_WM_PAINT()
    ON_WM_MOUSEMOVE()
    ON_MESSAGE(WM_MOUSEHOVER, OnMouseHover)
    ON_MESSAGE(WM_MOUSELEAVE, OnMouseLeave)
    ON_CONTROL_REFLECT(CBN_SELCHANGE, &CAddressComboBox::OnCbnSelchange)
END_MESSAGE_MAP()



// CAddressComboBox 消息處理程序



void CAddressComboBox::OnSize(UINT nType, int cx, int cy)
{
    CComboBox::OnSize(nType, cx, cy);

    COMBOBOXINFO comboBoxInfo;
    comboBoxInfo.cbSize = sizeof(COMBOBOXINFO);
    GetComboBoxInfo(&comboBoxInfo);

    CRect rcEdit;
    rcEdit.left = 22;
    rcEdit.right = comboBoxInfo.rcItem.right;
    rcEdit.top = 5;
    rcEdit.bottom = 23;
    ::MoveWindow(comboBoxInfo.hwndItem, rcEdit.left, rcEdit.top, rcEdit.Width(), rcEdit.Height(), TRUE);
}

void CAddressComboBox::DrawItem(LPDRAWITEMSTRUCT lpDrawItemStruct)
{
    HDC hDC = lpDrawItemStruct->hDC;
    int nItem = lpDrawItemStruct->itemID;
    CRect rcItem = lpDrawItemStruct->rcItem;
    HICON hIcon = (HICON)lpDrawItemStruct->itemData;

    if (hIcon)
    {
        DrawIconEx(hDC, 1, rcItem.top, hIcon, 16, 16, 0, 0, DI_NORMAL);
    }

    if (nItem != CB_ERR)
    {
        COLORREF clrBackground;
        COLORREF clrText;
        CRect rcText = rcItem;
        rcText.left = 18;
        if (lpDrawItemStruct->itemState & ODS_SELECTED)  //如果當前項被選中
        {
            clrBackground = ::GetSysColor(COLOR_HIGHLIGHT);
            clrText = ~::GetSysColor(COLOR_WINDOWTEXT) & 0x00FFFFFF;
        }
        else
        {
            clrBackground = ::GetSysColor(COLOR_WINDOW);
            clrText = ::GetSysColor(COLOR_WINDOWTEXT);
        }
        ::SetTextColor(hDC, clrText);
        ::SetBkColor(hDC, clrBackground);
        ::ExtTextOut(hDC, 0, 0, ETO_OPAQUE, rcText, NULL, 0, NULL);
        CString strItem;
        GetLBText(nItem, strItem);
        DrawText(hDC, strItem, strItem.GetLength(), rcText, DT_LEFT|DT_VCENTER|DT_SINGLELINE|DT_WORD_ELLIPSIS);
    }
}

void CAddressComboBox::MeasureItem(LPMEASUREITEMSTRUCT lpMeasureItemStruct)
{
    lpMeasureItemStruct->itemHeight = 18;
}

int CAddressComboBox::OnCreate(LPCREATESTRUCT lpCreateStruct)
{
    if (CComboBox::OnCreate(lpCreateStruct) == -1)
        return -1;

    SetItemHeight(-1, 22);

    if (!m_imgComboBox.IsNull()) return 0;
    if (!m_imgComboBoxThump.IsNull()) return 0;

    m_imgComboBox.LoadFromResource(AfxGetInstanceHandle(), IDB_COMBOBOX);
    m_imgComboBoxThump.LoadFromResource(AfxGetInstanceHandle(), IDB_COMBOBOX_THUMP);

    return 0;
}

void CAddressComboBox::OnPaint()
{
    CPaintDC dc(this); // device context for painting
    
    if (m_imgComboBox.IsNull()) return;
    if (m_imgComboBoxThump.IsNull()) return;

    CRect rcComboBox;
    GetClientRect(&rcComboBox);

    // 畫左邊
    CRect rcComboLeft = rcComboBox;
    rcComboLeft.right = 10;
    m_imgComboBox.Draw(dc.m_hDC, rcComboLeft, CRect(0,0,10,28));

    // 畫上邊
    CRect rcComboTop = rcComboBox;
    rcComboTop.left = 10;
    rcComboTop.top = 0;
    rcComboTop.bottom = 4;
    m_imgComboBox.Draw(dc.m_hDC, rcComboTop, CRect(10,0,20,4));

    // 畫下邊
    CRect rcComboBottom = rcComboBox;
    rcComboBottom.left = 10;
    rcComboBottom.top = 24;
    rcComboBottom.bottom = 28;
    m_imgComboBox.Draw(dc.m_hDC, rcComboBottom, CRect(10,24,20,28));

    // 繪制右邊的箭頭
    COMBOBOXINFO comboBoxInfo;
    comboBoxInfo.cbSize = sizeof(COMBOBOXINFO);
    GetComboBoxInfo(&comboBoxInfo);

    CRect rcComboThump = comboBoxInfo.rcButton;
    rcComboThump = comboBoxInfo.rcButton;
    rcComboThump.left -= 4;
    rcComboThump.right = rcComboThump.left + 18;
    rcComboThump.top = 4;
    rcComboThump.bottom = 22;

    if (m_bIsThumpHover)
    {
        if (m_bIsThumpDown)
        {
            m_imgComboBoxThump.Draw(dc.m_hDC, rcComboThump, CRect(44,2,63,20));
        }
        else
        {
            m_imgComboBoxThump.Draw(dc.m_hDC, rcComboThump, CRect(23,2,42,20));
        }
    }
    else
    {
        m_imgComboBoxThump.Draw(dc.m_hDC, rcComboThump, CRect(2,2,20,20));
    }

    HBRUSH hBrush = (HBRUSH)::GetStockObject(WHITE_BRUSH);
    FillRect(dc.m_hDC, CRect(5, 5, 24, 23), hBrush);
    if (m_hIcon)
    {
        DrawIconEx(dc.m_hDC, 5, 5, m_hIcon, 16, 16, 0, 0, DI_NORMAL);
    }
}

void CAddressComboBox::OnMouseMove(UINT nFlags, CPoint point)
{
    TRACKMOUSEEVENT tme;
    tme.cbSize = sizeof(TRACKMOUSEEVENT);
    tme.hwndTrack = m_hWnd;
    tme.dwFlags = TME_HOVER | TME_LEAVE;
    tme.dwHoverTime = 1;//HOVER_DEFAULT;
    TrackMouseEvent(&tme);

    CComboBox::OnMouseMove(nFlags, point);
}

LRESULT CAddressComboBox::OnMouseHover( WPARAM wParam, LPARAM lParam )
{
    if (!m_bIsThumpHover)
    {
        COMBOBOXINFO comboBoxInfo;
        comboBoxInfo.cbSize = sizeof(COMBOBOXINFO);
        GetComboBoxInfo(&comboBoxInfo);

        CRect rcEdit;
        ::GetClientRect(comboBoxInfo.hwndItem, &rcEdit);
        CRect rcComboThump = comboBoxInfo.rcButton;
        rcComboThump.left = 22 + rcEdit.Width();
        rcComboThump.top = 5;
        rcComboThump.bottom = 23;

        CPoint pt;
        pt.x = LOWORD(lParam);
        pt.y = HIWORD(lParam);

        if (rcComboThump.PtInRect(pt))
        {
            m_bIsThumpHover = TRUE;
            m_bIsThumpDown = wParam == MK_LBUTTON;
            Invalidate();
        }
    }

    return 0;
}

LRESULT CAddressComboBox::OnMouseLeave( WPARAM wParam, LPARAM lParam )
{
    m_bIsThumpHover = FALSE;
    m_bIsThumpDown = FALSE;
    Invalidate();

    return 0;
}

int CAddressComboBox::AddString( LPCTSTR lpszString, HICON hIcon )
{
    int nItem = CComboBox::AddString(lpszString);
    SetItemData(nItem, (DWORD)hIcon);
    return nItem;
}

void CAddressComboBox::OnCbnSelchange()
{
    int nItem = GetCurSel();
    if (nItem == -1) return;
    m_hIcon = (HICON)GetItemData(nItem);
    if (m_hIcon)
    {
        Invalidate();
    }
}