Self drawing of menu items and CListBox items

Self drawing of menu items

Self drawing of menu items

step ：
1. Add the menu item that needs self drawing MF_OWNERDRAW, Use ModeifyMenu Function is suitable for
2. Use WM_MEASUREITEM Set the width and height of menu items
3. Use WM_DRAWITEM Draw menu items

• Get menu , Menu item plus MF_OWNERDRAW

CMenu*pMenu=pFrame->GetMenu();
ASSERT(pFrame!=NULL);
//ASSERT () Is a macro that is often used when debugging programs , When the program is running, it evaluates the expression in brackets , If the expression is FALSE (0),  The program will report an error , And terminate execution .  If the expression is not 0, Then continue to execute the following statements . ... ASSERT  Only in Debug  Only valid in version , If compiled as Release  Version is ignored 
for(int i=0;i<5;i++)
	pMenu->ModifyMenu(IDM_COLOR_RED+i,MF_OWNERDRAW,IDM_COLOR_RED+i);
return TRUE;

• Set the width and height of menu items

void CMainFrame::OnMeasureItem(int nIDCtl,LPMEASUREITEMSTRUCT lpmis)
{
    
	lpmis->itemWidth=::GetSystemMetrics(SM_CYMENU)*4;
	lpmis->itemHeight=::GetSystemMetrics(SM_CYMENU);
}

• Draw menu items

Draw menu item steps
1. Highlight the selected item pBrush->CreateSolidBrush(::GetSysColor((lpdis->itemState & ODS_SELECTED) ? COLOR_HIGHLIGHT : COLOR_WINDOW));
2. Draw the selected item border dc.FrameRect(&(lpdis->rcItem), pBrush);
3.BitBlt Draw the left check mark （√）, Right rectangle fill color

void CMainFrame::OnDrawItem(int nIDCtl,LPDRAWITEMSTRUCT lpdis)
{
    
	BITMAP bm;
	CBitmap bitmap;
	bitmap.LoadOEMBitmap(OBM_CHECK);
	bitmap.GetObject(sizeof(bm),&bm);//int GetObject(int nCount,LPVOID lpObject) const;
	//CGdiObject::GetObject  Fill the buffer with data that defines the specified object &bm
	//nCount :Specifies the number of bytes to copy into the lpObject buffer.
	//lpObject:Points to a user-supplied buffer that is to receive the information.
	//https://docs.microsoft.com/en-us/cpp/mfc/reference/cgdiobject-class?view=msvc-170
	CDC dc;
	dc.Attach(lpdis->hDC);
	CBrush* pBrush = new CBrush;
	// Highlight the selected menu item 
	pBrush->CreateSolidBrush(::GetSysColor((lpdis->itemState & ODS_SELECTED) ? COLOR_HIGHLIGHT : COLOR_WINDOW));
	// Picture frame 
	dc.FrameRect(&(lpdis->rcItem), pBrush);
		if (lpdis->itemState & ODS_CHECKED)
	{
    
		CDC dcMem;
		dcMem.CreateCompatibleDC(&dc);
		CBitmap* pOldBitMap = dcMem.SelectObject(&bitmap);
		
		dc.BitBlt(lpdis->rcItem.left + 4, lpdis->rcItem.top + (((lpdis->rcItem.bottom - lpdis->rcItem.top) - bm.bmHeight) / 2), 
			bm.bmWidth, bm.bmHeight, &dcMem, 0, 0, SRCCOPY);
			/* BOOL BitBlt( int x, int y, int nWidth, int nHeight, CDC* pSrcDC, int xSrc, int ySrc, DWORD dwRop); */
		dcMem.SelectObject(pOldBitMap);
	}
	pBrush=new CBrush(col[lpdis->itemID-ID_COLOR_RED]);
	CRect rect = lpdis->rcItem;
	rect.DeflateRect(6,4);// Reduce the width and height , Don't move top And left
	rect.left += bm.bmWidth;
	dc.FillRect(rect, pBrush);
	delete pBrush;
	dc.Detach();
	CFrameWnd::OnDrawItem(nIDCtl, lpdis);
}

• design sketch
  

CListBox Self drawing of items

step ：
1. Cover ** CListBox::PreCreateWindow** function , Make sure cs style contain ** LBS_OWNERDRAWFIXED** or ** LBS_OWNERDRAWVARIABLE**
2. Cover ** CListBox::MeasureItem** Set the width and height of menu items
3. Cover ** CListBox::DrawItem** Draw menu items

class CMyListBox :public CListBox
{
    
public:
	virtual BOOL PreCreateWindow(CREATESTRUCT& cs);
	virtual void DrawItem(LPDRAWITEMSTRUCT lpDrawItemStruct);
	virtual void MeasureItem(LPMEASUREITEMSTRUCT lpMeasureItemStruct);

	int AddIcon(HICON hIcon);
	void ProjectImage(CDC* pDC, LPRECT pRect, COLORREF clrBackColor);


	DECLARE_MESSAGE_MAP()
	afx_msg void OnLbnSelchange();
};

• Cover ** CListBox::PreCreateWindow** function , Make sure cs style contain ** LBS_OWNERDRAWFIXED** or ** LBS_OWNERDRAWVARIABLE**

CIconListBox::PreCreateWindow(CREATESTRUCT& cs)
{
    

	cs.style |=LBS_OWNERDRAWFIXED;
	// Indicates that it does not contain LBS_OWNERDRAWFIXED|LBS_SORT
	cs.style &=~(LBS_OWNERDRAWFIXED|LBS_SORT);
}

• Cover ** CListBox::MeasureItem** function , Set up listbox item Height and width

void CIconListBox::MeasureItem(LPMEASUREITEMSTRUCT lpmis)
{
    
	lpmis->itemHeight = 32;
}

• Cover ** CListBox::DrawItem** function , Began to draw ListBox term

void CMyListBox::DrawItem(LPDRAWITEMSTRUCT lpdis)
{
    
    CDC dc;
    // load DrawItem dc
    dc.Attach(lpdis->hDC);
    CRect rect = lpdis->rcItem;
    UINT nIndex = lpdis->itemID;
    // Draw the selected item to highlight 
    CBrush* pBrush = new CBrush(::GetSysColor(lpdis->itemState & ODS_SELECTED ? COLOR_HIGHLIGHT : COLOR_WINDOW));
    dc.FillRect(rect, pBrush);
    delete pBrush;
    // Draw the focus rectangle 
    if (lpdis->itemState&ODS_FOCUS)
    {
    
        dc.DrawFocusRect(rect);
    }
    if (nIndex!=(UINT)-1)
    {
    
        dc.DrawIcon(rect.left + 4, rect.top + 2, (HICON)GetItemData(nIndex));
    }
    /* BOOL DrawIcon( int x, int y, HICON hIcon ); //Retrieves the application-supplied doubleword value associated with the specified list-box item. DWORD_PTR GetItemData( int nIndex ) const; */
    dc.Detach();
}

• Set up ListBox term Icon

int CMyListBox::AddIcon(HICON hIcon)
{
    
    int nIndex=AddString(_T(""));
    if ((nIndex!=LB_ERR)&&(nIndex!=LB_ERRSPACE))
    {
    
        SetItemData(nIndex, (DWORD)hIcon);
    }
    return nIndex;
}

• Displayed in the rcImage Area

void CMyListBox::ProjectImage(CDC* pDC, LPRECT pRect, COLORREF clrBackColor)
{
    
    CDC dcMem;
    dcMem.CreateCompatibleDC(pDC);
    CBitmap bitmap;
    bitmap.CreateCompatibleBitmap(pDC, 32, 32);
    CBitmap* pOldBitmap = dcMem.SelectObject(&bitmap);
    CBrush* pBrush = new CBrush(clrBackColor);
    dcMem.FillRect(CRect(0, 0, 32, 32), pBrush);

    delete pBrush;

    int nIndex = GetCurSel();
    if (nIndex != LB_ERR)
        dcMem.DrawIcon(0, 0, (HICON)GetItemData(nIndex));
    pDC->StretchBlt(pRect->left, pRect->top, pRect->right - pRect->left, pRect->bottom - pRect->top, &dcMem, 0, 0, 32, 32, SRCCOPY);
    dcMem.SelectObject(pOldBitmap);

}

• design sketch