📄 wtl for mfc programmers, part v - advanced dialog ui classes - wtl.htm
字号:
<html>
<head>
<title>WTL for MFC Programmers, Part V - Advanced Dialog UI Classes</title>
<meta http-equiv="Content-Type" content="text/html; charset=gb2312">
</head>
<body bgcolor="#33CCCC" text="#000000">
<p align="center"><b><font style="FONT-SIZE: 16pt" size="4" color="#0033CC">WTL
for MFC Programmers, Part V - Advanced Dialog UI Classes</font></b><br>
<br>
</p>
<p align="left">原作 ：<b><font color="#CC3366">Michael Dunn</font></b> [<a href="http://www.codeproject.com/wtl/WTL4MFC5.asp">英文原文</a>]<br>
翻译 ：<a href="mailto:inte2000@163.com">Orbit(桔皮干了)</a> [<a href="http://www.winmsg.com/cn/orbit.htm">http://www.winmsg.com/cn/orbit.htm</a>]</p>
<p align="left"><a href="demo/WTL4MFC5_demo.zip">下载演示程序代码</a></p>
<H2><font color="#FFFF66">本章内容</font></H2>
<UL>
<LI><A href="#intro">第五章介绍</A>
<LI><A href="#specialized">特别的自画和外观定制类</A>
<UL>
<LI><A href="#cownerdraw">COwnerDraw</A>
<LI><A href="#ccustomdraw">CCustomDraw</A></LI>
</UL>
<LI><A href="#newwtlctrls">WTL的新控件</A>
<UL>
<LI><A href="#newcbitmapbutton">CBitmapButton</A>
<LI><A href="#cchecklist">CCheckListViewCtrl</A>
<LI><A href="#treeex">CTreeViewCtrlEx 和 CTreeItem</A>
<LI><A href="#chyperlink">CHyperLink</A></LI>
</UL>
<LI><A href="#uiupdctrl">对话框中控件的UI Updating</A>
<LI><A href="#ddv">DDV</A>
<UL>
<LI><A href="#ddvfail">处理DDV验证失败</A> </LI>
</UL>
<LI><A href="#resizing">改变对话框的大小</A>
<LI><A href="#upnext">继续</A>
<LI><A href="#references">参考</A>
<LI><A href="#revisionhistory">修改记录</A> </LI>
</UL>
<H2><A name=intro></A><font color="#FFFF66">第五章介绍</font></H2>
<p>在上一篇文章我们介绍了一些与对话框和控件有关的WTL的特性，它们和MFC的相应的类作用相同。本文将介绍一些新类实现高级界面特性新类：控件自画和自定外观控件，新的WTL控件，UI
updating和对话框数据验证(DDV)。</p>
<H2><A name=specialized></A><font color="#FFFF66">特别的自画和外观定制类</font></H2>
<P>由于自画和定制外观控件在图形用户界面中是很常用的手段，所以WTL提供了几个嵌入类来完成这些令人厌烦的工作。我接着就会介绍它们，事实上我们在上一个例子工程ControlMania2的结尾部分已经这么做了。如果你正随着我的讲解用应用程序生成向导创建新工程，请不要忘了使用无模式对话框，为了使正常工作必须使用无模式对话框，我会在<a href="#uiupdctrl">对话框中控件的UI
Updating</a>部分详细解释为什么这样作。</P>
<H3><A name=cownerdraw></A><font color="#FFFF66">COwnerDraw</font></H3>
<P>控件的自画需要响应四个消息：WM_MEASUREITEM, WM_DRAWITEM, WM_COMPAREITEM, 和WM_DELETEITEM，在atlframe.h头文件中定义的COwnerDraw类可以简化这些工作，使用这个类就不需要处理这四个消息，你只需将消息链入COwnerDraw，它会调用你的类中的重载函数。</P>
<p>如何将消息链入COwnerDraw取决与你是否将消息反射给控件，两种方法有些不同。下面是COwnerDraw类的消息映射链，它使得两种方法的差别更加明显：</p>
<PRE><SPAN class=cpp-keyword><font color="#0033FF">template</font></SPAN> <font color="#0033FF"><<SPAN class=cpp-keyword>class</SPAN> T> <SPAN class=cpp-keyword>class</SPAN> COwnerDraw
{
<SPAN class=cpp-keyword>public</SPAN>:
BEGIN_MSG_MAP(COwnerDraw<T>)
MESSAGE_HANDLER(WM_DRAWITEM, OnDrawItem)
MESSAGE_HANDLER(WM_MEASUREITEM, OnMeasureItem)
MESSAGE_HANDLER(WM_COMPAREITEM, OnCompareItem)
MESSAGE_HANDLER(WM_DELETEITEM, OnDeleteItem)
ALT_MSG_MAP(<SPAN class=cpp-literal>1</SPAN>)
MESSAGE_HANDLER(OCM_DRAWITEM, OnDrawItem)
MESSAGE_HANDLER(OCM_MEASUREITEM, OnMeasureItem)
MESSAGE_HANDLER(OCM_COMPAREITEM, OnCompareItem)
MESSAGE_HANDLER(OCM_DELETEITEM, OnDeleteItem)
END_MSG_MAP()
};</font></PRE>
<P>注意，消息映射链的主要部分处理WM_*消息，而ATL部分处理反射的消息，OCM_*。自画的通知消息就像WM_NOTIFY消息一样，你可以在父窗口处理它们，也可以将它们反射会控件，如果你使用前一种方法，消息被直接链入COwnerDraw：</P>
<PRE><SPAN class=cpp-keyword><font color="#0033FF">class</font></SPAN><font color="#0033FF"> CSomeDlg : <SPAN class=cpp-keyword>public</SPAN> COwnerDraw<CSomeDlg>, ...
{
BEGIN_MSG_MAP(CSomeDlg)
<SPAN class=cpp-comment>//...</SPAN>
CHAIN_MSG_MAP(COwnerDraw<CSomeDlg>)
END_MSG_MAP()
<SPAN class=cpp-keyword>void</SPAN> DrawItem ( LPDRAWITEMSTRUCT lpdis );
};</font></PRE>
<P>当然，如果你想要控件自己处理这些消息，你需要使用CHAIN_MSG_MAP_ALT宏将消息链入ALT_MSG_MAP(1)部分：</P>
<PRE><SPAN class=cpp-keyword><font color="#0033FF">class</font></SPAN><font color="#0033FF"> CSomeButtonImpl : <SPAN class=cpp-keyword>public</SPAN> COwnerDraw<CSomeButtonImpl>, ...
{
BEGIN_MSG_MAP(CSomeButtonImpl)
<SPAN class=cpp-comment>//...</SPAN>
CHAIN_MSG_MAP_ALT(COwnerDraw<CSomeButtonImpl>, <SPAN class=cpp-literal>1</SPAN>)
DEFAULT_REFLECTION_HANDLER()
END_MSG_MAP()
<SPAN class=cpp-keyword>void</SPAN> DrawItem ( LPDRAWITEMSTRUCT lpdis );
};</font></PRE>
<P>COwnerDraw类将对消息传递的参数展开，然后调用你的类中的实现函数。上面的例子中，我们自己的类实现DrawItem()函数，当有WM_DRAWITEM或OCM_DRAWITEM消息被链入COwnerDraw时，这个函数就会被调用。你可以重载的方法有：</P>
<PRE><SPAN class=cpp-keyword><font color="#0033FF">void</font></SPAN><font color="#0033FF"> DrawItem(LPDRAWITEMSTRUCT lpDrawItemStruct);
<SPAN class=cpp-keyword>void</SPAN> MeasureItem(LPMEASUREITEMSTRUCT lpMeasureItemStruct);
<SPAN class=cpp-keyword>int</SPAN> CompareItem(LPCOMPAREITEMSTRUCT lpCompareItemStruct);
<SPAN class=cpp-keyword>void</SPAN> DeleteItem(LPDELETEITEMSTRUCT lpDeleteItemStruct);</font></PRE>
<P>如果你不想处理某个消息，你可以调用SetMsgHandled(false)，消息会被传递给消息映射链中的其他响应者。SetMsgHandled()事实上是COwnerDraw类的成员函数，但是它的作用和在BEGIN_MSG_MAP_EX()中使用SetMsgHandled()一样。</P>
<p>对于ControlMania2，它从ControlMania1中的树控件开始，添加了自画按钮处理反射的WM_DRAWITEM消息，下面是资源编辑器中的新按钮：</p>
<P><IMG height=346 alt=" [Owner-drawn button 1 - 7K] "
src="images/cm2_od15.png"
width=325 align=bottom border=0></P>
<P>现在我们需要一个新类实现自画按钮：</P>
<PRE><SPAN class=cpp-keyword><font color="#0033FF">class</font></SPAN><font color="#0033FF"> CODButtonImpl : <SPAN class=cpp-keyword>public</SPAN> CWindowImpl<CODButtonImpl, CButton>,
<SPAN class=cpp-keyword>public</SPAN> COwnerDraw<CODButtonImpl>
{
<SPAN class=cpp-keyword>public</SPAN>:
BEGIN_MSG_MAP_EX(CODButtonImpl)
CHAIN_MSG_MAP_ALT(COwnerDraw<CODButtonImpl>, <SPAN class=cpp-literal>1</SPAN>)
DEFAULT_REFLECTION_HANDLER()
END_MSG_MAP()
<SPAN class=cpp-keyword>void</SPAN> DrawItem ( LPDRAWITEMSTRUCT lpdis );
};</font></PRE>
<P>DrawItem()使用了像BitBlt()这样的GDI函数向按钮的表面画位图，代码应该很容易理解，因为WTL使用的类名和函数名都和MFC类似。</P>
<PRE><SPAN class=cpp-keyword><font color="#0033FF">void</font></SPAN><font color="#0033FF"> CODButtonImpl::DrawItem ( LPDRAWITEMSTRUCT lpdis )
{
<SPAN class=cpp-comment>// NOTE: m_bmp is a CBitmap init'ed in the constructor.</SPAN>
CDCHandle dc = lpdis->hDC;
CDC dcMem;
dcMem.CreateCompatibleDC ( dc );
dc.SaveDC();
dcMem.SaveDC();
<SPAN class=cpp-comment>// Draw the button's background, red if it has the focus, blue if not.</SPAN>
<SPAN class=cpp-keyword>if</SPAN> ( lpdis->itemState & ODS_FOCUS )
dc.FillSolidRect ( &lpdis->rcItem, RGB(<SPAN class=cpp-literal>255</SPAN>,<SPAN class=cpp-literal>0</SPAN>,<SPAN class=cpp-literal>0</SPAN>) );
<SPAN class=cpp-keyword>else</SPAN>
dc.FillSolidRect ( &lpdis->rcItem, RGB(<SPAN class=cpp-literal>0</SPAN>,<SPAN class=cpp-literal>0</SPAN>,<SPAN class=cpp-literal>255</SPAN>) );
<SPAN class=cpp-comment>// Draw the bitmap in the top-left, or offset by 1 pixel if the button</SPAN>
<SPAN class=cpp-comment>// is clicked.</SPAN>
dcMem.SelectBitmap ( m_bmp );
<SPAN class=cpp-keyword>if</SPAN> ( lpdis->itemState & ODS_SELECTED )
dc.BitBlt ( <SPAN class=cpp-literal>1</SPAN>, <SPAN class=cpp-literal>1</SPAN>, <SPAN class=cpp-literal>80</SPAN>, <SPAN class=cpp-literal>80</SPAN>, dcMem, <SPAN class=cpp-literal>0</SPAN>, <SPAN class=cpp-literal>0</SPAN>, SRCCOPY );
<SPAN class=cpp-keyword>else</SPAN>
dc.BitBlt ( <SPAN class=cpp-literal>0</SPAN>, <SPAN class=cpp-literal>0</SPAN>, <SPAN class=cpp-literal>80</SPAN>, <SPAN class=cpp-literal>80</SPAN>, dcMem, <SPAN class=cpp-literal>0</SPAN>, <SPAN class=cpp-literal>0</SPAN>, SRCCOPY );
dcMem.RestoreDC(-<SPAN class=cpp-literal>1</SPAN>);
dc.RestoreDC(-<SPAN class=cpp-literal>1</SPAN>);
}</font></PRE>
<P>我们的按钮看起来是这个样子：</P>
<P><IMG height=324 alt=" [Owner-drawn button - 11K] "
src="images/cm2_od25.png"
width=305 align=bottom border=0></P>
<H3><A name=ccustomdraw></A><font color="#FFFF66">CCustomDraw</font></H3>
<P>CCustomDraw类使用和COwnerDraw类相同的方法处理NM_CUSTOMDRAW消息，对于自定绘制的每个阶段都有相应的重载函数：</P>
<PRE><font color="#0033FF">DWORD OnPrePaint(<SPAN class=cpp-keyword>int</SPAN> idCtrl, LPNMCUSTOMDRAW lpNMCD);
DWORD OnPostPaint(<SPAN class=cpp-keyword>int</SPAN> idCtrl, LPNMCUSTOMDRAW lpNMCD);
DWORD OnPreErase(<SPAN class=cpp-keyword>int</SPAN> idCtrl, LPNMCUSTOMDRAW lpNMCD);
DWORD OnPostErase(<SPAN class=cpp-keyword>int</SPAN> idCtrl, LPNMCUSTOMDRAW lpNMCD);
DWORD OnItemPrePaint(<SPAN class=cpp-keyword>int</SPAN> idCtrl, LPNMCUSTOMDRAW lpNMCD);
DWORD OnItemPostPaint(<SPAN class=cpp-keyword>int</SPAN> idCtrl, LPNMCUSTOMDRAW lpNMCD);
DWORD OnItemPreErase(<SPAN class=cpp-keyword>int</SPAN> idCtrl, LPNMCUSTOMDRAW lpNMCD);
DWORD OnItemPostEraset(<SPAN class=cpp-keyword>int</SPAN> idCtrl, LPNMCUSTOMDRAW lpNMCD);
DWORD OnSubItemPrePaint(<SPAN class=cpp-keyword>int</SPAN> idCtrl, LPNMCUSTOMDRAW lpNMCD);</font></PRE>
<P>这些函数默认都是返回CDRF_DODEFAULT，如果想自画控件或返回一个不同的值，就需要重载这些函数：</P>
<p>你可能注意到上面的屏幕截图将“道恩”(Dawn：女名)显示成绿色，这是因为CBuffyTreeCtrl将消息链入CCustomDraw并重载了OnPrePaint()和OnItemPrePaint()方法。向树控件中添加节点时，节点的item
data字段被设置成1，OnItemPrePaint()检查这个值，然后改变文字的颜色。</p>
<PRE><font color="#0033FF">DWORD CBuffyTreeCtrl::OnPrePaint(<SPAN class=cpp-keyword>int</SPAN> idCtrl,
⌨️ 快捷键说明
复制代码
Ctrl + C
搜索代码
Ctrl + F
全屏模式
F11
切换主题
Ctrl + Shift + D
显示快捷键
?
增大字号
Ctrl + =
减小字号
Ctrl + -