void CMyTreeCtrl::OnPaint()
{
CPaintDC dc(this); // device context for painting
// Create a memory DC compatible with the paint DC
CDC memDC;
memDC.CreateCompatibleDC( &dc );
CRect rcClip, rcClient;
dc.GetClipBox( &rcClip );
GetClientRect(&rcClient);
// Select a compatible bitmap into the memory DC
CBitmap bitmap;
bitmap.CreateCompatibleBitmap( &dc, rcClient.Width(), rcClient.Height() );
CBitmap *pOldBitmap=memDC.SelectObject( &bitmap );
// Set clip region to be same as that in paint DC
CRgn rgn;
rgn.CreateRectRgnIndirect( &rcClip );
memDC.SelectClipRgn(&rgn);
rgn.DeleteObject();
// First let the control do its default drawing.
CWnd::DefWindowProc( WM_PAINT, (WPARAM)memDC.m_hDC, 0 );
HTREEITEM hItem = GetFirstVisibleItem();
int n = GetVisibleCount()+1;
while( hItem && n--)
{
CRect rect;
// Do not meddle with selected items or drop highlighted items
UINT selflag = TVIS_DROPHILITED | TVIS_SELECTED;
Color_Font cf;
if ( !(GetItemState( hItem, selflag ) & selflag ) && m_mapColorFont.Lookup( hItem, cf ))
{
CFont *pFontDC;
CFont fontDC;
LOGFONT logfont;
if( cf.logfont.lfFaceName[0] != '\0' )
{
logfont = cf.logfont;
}
else
{
// No font specified, so use window font
CFont *pFont = GetFont();
pFont->GetLogFont( &logfont );
}
if( GetItemBold( hItem ) )
{
logfont.lfWeight = 700;
}
fontDC.CreateFontIndirect( &logfont );
pFontDC = memDC.SelectObject( &fontDC );
if( cf.color != (COLORREF)-1 )
{
memDC.SetTextColor( cf.color );
}
CString sItem = GetItemText( hItem );
GetItemRect( hItem, &rect, TRUE );
memDC.SetBkColor( GetSysColor( COLOR_WINDOW ) );
memDC.TextOut( rect.left+2, rect.top+1, sItem );
memDC.SelectObject( pFontDC );
}
hItem = GetNextVisibleItem( hItem );
}
dc.BitBlt( rcClip.left, rcClip.top, rcClip.Width(), rcClip.Height(), &memDC,
rcClip.left, rcClip.top, SRCCOPY );
memDC.SelectObject(pOldBitmap);
bitmap.DeleteObject();
}
void CImageTreeCtrl::OnPaint()
{
//获取当前绘制对象的DC
CPaintDC dc(this);
// 使用将要绘制的对象的DC创建一个memory DC
//memory device context的概念：是在内存中创建一个结构来反映一个显示（屏幕区域、窗口、
//打印机等）的表面。可以用来先在内存中准备好要显示的图像，从而实现双缓存，提高刷新
//速度减少刷新时产生的闪烁。
CDC memDC;
//从当前DC创建内存对象
memDC.CreateCompatibleDC( &dc );
//定义CRect对象，用来确定区域
CRect rcClip, rcClient;
//获取当前对象的边界区域
dc.GetClipBox( &rcClip );
//获取当前对象的用户区域
GetClientRect(&rcClient);
// Select a compatible bitmap into the memory DC
//创建一个bmp文件，作为memDC的内容
//该文件的大小与用于区域相同
CBitmap bitmap;
bitmap.CreateCompatibleBitmap( &dc, rcClient.Width(), rcClient.Height() );
memDC.SelectObject( &bitmap );
// Set clip region to be same as that in paint DC
//通过对象的边界区域创建CRgn对象
CRgn rgn;
rgn.CreateRectRgnIndirect( &rcClip );
//rcClip.bottom = rcClip.bottom + 10;
memDC.SelectClipRgn(&rgn);
rgn.DeleteObject();
// First let the control do its default drawing.
//首先让控件自己进行默认的绘制，绘制到内存中
CWnd::DefWindowProc( WM_PAINT, (WPARAM)memDC.m_hDC, 0 );
//获取树状控件的第一个节点
HTREEITEM hItem = GetFirstVisibleItem();
//遍历这棵树
int n = GetVisibleCount()+1;
while( hItem && n--)
{
CRect rect;
// Do not meddle with selected items or drop highlighted items
//不对选中的节点和实行拖放功能的节点进行操作
UINT selflag = TVIS_DROPHILITED;// | TVIS_SELECTED;
//定义字体、颜色
Color_Font cf;
//设置字体
if ( !(GetItemState( hItem, selflag ) & selflag )
&& m_mapColorFont.Lookup( hItem, cf ))
{
CFont *pFontDC;
CFont fontDC;
LOGFONT logfont;
if( cf.logfont.lfFaceName[0] != '/0' )
{
//用户定义了字体
logfont = cf.logfont;
}
else
{
// 用户没有定义，使用系统字体
CFont *pFont = GetFont();
pFont->GetLogFont( &logfont );
}
//用户是否设定节点为加粗
if( GetItemBold( hItem ) )
logfont.lfWeight = 700;
//创建字体
fontDC.CreateFontIndirect( &logfont );
pFontDC = memDC.SelectObject( &fontDC );
//设置字体颜色
if( cf.color != (COLORREF)-1 )
memDC.SetTextColor( cf.color );
//获取节点文字
CString sItem = GetItemText( hItem );
//获取节点区域
GetItemRect( hItem, &rect, TRUE );
//rect.bottom = rect.bottom + 2;
//设置背景色为系统色
memDC.FillSolidRect(&rect,GetSysColor( COLOR_WINDOW ));//clr);
memDC.SetBkColor( GetSysColor( COLOR_WINDOW ) );
//向内存中的图片写入内容,为该节点的内容
memDC.TextOut( rect.left+2, rect.top+1, sItem );
memDC.SelectObject( pFontDC );
}
hItem = GetNextVisibleItem( hItem );
}
dc.BitBlt( rcClip.left, rcClip.top, rcClip.Width(), rcClip.Height(), &memDC,
rcClip.left, rcClip.top, SRCCOPY );
}
