📄 vc++动态链接库编程之mfc扩展 dll-开发者网络-dll-天极y2esky.htm
字号:
<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN" "http://www.w3c.org/TR/1999/REC-html401-19991224/loose.dtd">
<!-- saved from url=(0040)http://dev.yesky.com/359/2145859_1.shtml -->
<HTML lang=zh-CN xmlns="http://www.w3.org/1999/xhtml"><HEAD><TITLE>VC++动态链接库编程之MFC扩展 DLL-开发者网络-dll-天极Yesky</TITLE>
<META content="VC++动态链接库编程之MFC扩展 DLL," name=description>
<META content="VC++动态链接库编程之MFC扩展 DLL," name=keywords>
<META content="天极Yesky | 全球中文IT第一门户" name=author>
<META content="天极Yesky | 全球中文IT第一门户" name=Copyright>
<META http-equiv=Content-Type content="text/html; charset=gb2312">
<META http-equiv=Content-Language content=zh-CN><LINK media=all
href="VC++动态链接库编程之MFC扩展 DLL-开发者网络-dll-天极Y2esky.files/y_mobile_content.css"
type=text/css rel=stylesheet>
<SCRIPT
src="VC++动态链接库编程之MFC扩展 DLL-开发者网络-dll-天极Y2esky.files/showlay.js"></SCRIPT>
<META content="MSHTML 6.00.2900.3199" name=GENERATOR></HEAD>
<BODY><!--页面头部--><!--头部-->
<DIV id=topmenu><A href="http://www.yesky.com/">Yesky首页</A>| <A
href="http://product.yesky.com/">产品报价</A>| <A
href="http://cseek.yesky.com/">行情</A>| <A href="http://mobile.yesky.com/">手机</A>
| <A href="http://digital.yesky.com/">数码</A> | <A
href="http://notebook.yesky.com/">笔记本</A> | <A
href="http://pc.yesky.com/">台式机</A> | <A href="http://diy.yesky.com/">DIY硬件</A>
| <A href="http://oa.yesky.com/">外设</A> | <A href="http://net.yesky.com/">网络</A>
| <A href="http://dh.yesky.com/">数字家庭</A> | <A
href="http://lab.yesky.com/">评测</A> | <A href="http://soft.yesky.com/">软件</A> |
<A href="http://e.yesky.com/">e时代</A> | <A href="http://game.yesky.com/">游戏</A>
| <A href="http://pic.yesky.com/">图片</A> | <A
href="http://desktop.yesky.com/">壁纸</A> | <A href="http://q.yesky.com/">群乐</A> |
<A href="http://my.yesky.com/">社区</A> | <A href="http://blog.yesky.com/">博客</A>
| <A href="http://www.mydown.com/">下载</A></DIV>
<DIV id=topbox>
<DIV class=tleft><A href="http://www.yesky.com/"><IMG alt=天极Yesky_全球中文IT第一门户
src="VC++动态链接库编程之MFC扩展 DLL-开发者网络-dll-天极Y2esky.files/logo.gif"
border=0></A></DIV>
<DIV class=tad><SPAN id=ad1></SPAN></DIV>
<DIV id=search>
<DIV>
<FORM name=searchform action=http://search.chinabyte.com/search method=get
target=_blank><INPUT id=searchzz onmouseover=this.focus() onfocus=this.select()
name=q><INPUT type=hidden value=GB2312 name=encoding><INPUT type=hidden
value=connect name=dir><INPUT type=hidden value=20002 name=cid><INPUT id=search_btn type=submit value=天极搜索> </FORM></DIV>
<DIV class=tdq>
<DIV class=rightarea><A href="http://bj.yesky.com/">北京</A> <A
href="http://hd.yesky.com/">上海</A> <A href="http://gd.yesky.com/">广东</A> <A
href="http://xa.yesky.com/">西安</A><BR><A href="http://cq.yesky.com/">重庆</A> <A
href="http://cd.yesky.com/">成都</A> <A href="http://sy.yesky.com/">沈阳</A> <A
href="http://js.yesky.com/">江苏</A> </DIV>
<DIV class=rightarea_right><A
href="http://my.yesky.com/">用户<BR>登录</A></DIV></DIV></DIV>
<DIV class=tright>
<DIV class=box1>
<SCRIPT src="VC++动态链接库编程之MFC扩展 DLL-开发者网络-dll-天极Y2esky.files/content_text_ad.js"
type=text/javascript></SCRIPT>
</DIV></DIV></DIV>
<SCRIPT src="VC++动态链接库编程之MFC扩展 DLL-开发者网络-dll-天极Y2esky.files/flash.js"
type=text/javascript></SCRIPT>
<DIV id=childmenu><A href="http://soft.yesky.com/">软件频道></A><A
href="http://dev.yesky.com/">程序开发></A><A
href="http://dev.yesky.com/devjava/">Java</A><A
href="http://dev.yesky.com/ysdevvb">VB</A><A
href="http://dev.yesky.com/ysdevvc">VC</A><A
href="http://dev.yesky.com/ysdevdelphi">Delphi</A><A
href="http://dev.yesky.com/ysdevc">C/C++</A><A
href="http://dev.yesky.com/web/">Web开发</A><A
href="http://dev.yesky.com/msdn/">微软专栏</A><A
href="http://dev.yesky.com/devydkf/">移动</A><A
href="http://dev.yesky.com/devsjk/">数据库</A><A
href="http://dev.yesky.com/ysdevcxrs">程序人生</A><A
href="http://dev.yesky.com/ysdevrjgc">软件工程</A>|<A
href="http://soft.yesky.com/lesson/">产品中心</A><A
href="http://www.mydown.com/soft/develop/news.shtml">下载</A><A
href="http://q.yesky.com/group/202019"><FONT color=#ff0000>群乐:<FONT
face=Verdana>Vista系统</FONT></FONT></A></DIV><!--导航条-->
<DIV id=location>
<DIV class=loleft>您现在的位置: <A href="http://www.yesky.com/">天极网</A> > <A
href="http://dev.yesky.com/">开发频道</A> > VC++动态链接库编程之MFC扩展 DLL</DIV>
<DIV class=adright><SPAN id=ad2></SPAN></DIV></DIV><!--内容块开始-->
<DIV id=conbox><!--左边开始-->
<DIV id=conleft>
<DIV id=contopla1>
<DIV id=__001>
<DIV class=qkong></DIV>
<DIV class=qw1>全文</DIV>
<DIV class=zkong>
<DIV class=kl></DIV>
<DIV class=bj><A href="http://dev.yesky.com/359/2145859_1.shtml#pls"
target=_self>评论</A></DIV>
<DIV class=kr></DIV><!-- Error -->
<SCRIPT type=text/javascript>
var titiepic ="#";
if (titiepic!="#")
{
document.write("<div class=\"kl\"></div><div class=\"bj\"><a href=\"#\" target=\"_blank\">图片</a></div><div class=\"kr\"></div>");
}
</SCRIPT>
<!-- Error --></DIV></DIV></DIV>
<DIV class=topadbg><SPAN id=ad10></SPAN></DIV><A name=top></A>
<DIV id=contitle>
<H1>VC++动态链接库编程之MFC扩展 DLL</H1></DIV>
<DIV id=conauthor><SPAN>2005-10-10 08:52 </SPAN><SPAN>作者: 宋宝华 </SPAN><SPAN>出处:
天极网 </SPAN><SPAN>责任编辑:<A title=向本编辑提问
href="http://comments.yesky.com/t/·½ÖÛ/6,324/2145859.shtml" target=_blank>方舟</A>
</SPAN></DIV>
<DIV class=topadbg><SPAN id=ad9></SPAN></DIV>
<DIV id=conneirong><SPAN id=ad3></SPAN>
<DIV class=guanggao><SPAN id=contentAdv></SPAN></DIV> <B>6.3
MFC扩展DLL的加载</B><BR><BR> 6.3.1
隐式加载<BR><BR> 我们在6.2工程所在的工作区中添加一个LoadExtDllDlg工程,用于演示MFC扩展DLL的加载。在LoadExtDllDlg工程中添加一个如图16所示的对话框,这个对话框上包括一个“调用DLL”按钮。<BR><BR>
<TABLE width="90%" align=center border=0>
<TBODY>
<TR>
<TD>
<DIV align=center><IMG
src="VC++动态链接库编程之MFC扩展 DLL-开发者网络-dll-天极Y2esky.files/4o3b052d7377.jpg"
border=0><BR>图16
MFC扩展DLL调用工程中的对话框</DIV></TD></TR></TBODY></TABLE><BR> 在与图16对应对话框类实现文件的头部添加:<BR><BR>
<TABLE borderColor=#cccccc width="90%" align=center bgColor=#e3e3e3 border=1>
<TBODY>
<TR>
<TD>// LoadExtDllDlg.cpp : implementation file<BR>//<BR><BR>#include
"..\ExtDialog.h"<BR>#pragma comment( lib, "ExtDll.lib"
)<BR><BR>而“调用DLL”按钮的单击事件的消息处理函数为:<BR><BR>void
CLoadExtDllDlg::OnDllcallButton() <BR>{<BR> CExtDialog
extDialog;<BR> extDialog.DoModal();<BR>}</TD></TR></TBODY></TABLE><BR> 当我们单击“调用DLL”的时候,弹出了如图15的对话框。<BR><BR> 为提供给用户隐式加载(MFC扩展DLL一般使用隐式加载,具体原因见下节),MFC扩展DLL需要提供三个文件:<BR><BR> (1)描述DLL中扩展类的头文件;<BR><BR> (2)与动态链接库对应的.LIB文件;<BR><BR> (3)动态链接库.DLL文件本身。<BR><BR> 有了这三个文件,应用程序的开发者才可充分利用MFC扩展DLL。<BR><BR> 6.3.2
显示加载<BR><BR> 显示加载MFC扩展DLL应使用MFC全局函数AfxLoadLibrary而不是WIN32
API中的LoadLibrary。AfxLoadLibrary 最终也调用了
LoadLibrary这个API,但是在调用之前进行了线程同步的处理。<BR><BR> AfxLoadLibrary 的函数原型与
LoadLibrary完全相同,为:<BR><BR>
<TABLE borderColor=#cccccc width="90%" align=center bgColor=#e3e3e3 border=1>
<TBODY>
<TR>
<TD>HINSTANCE AFXAPI AfxLoadLibrary( LPCTSTR lpszModuleName
);</TD></TR></TBODY></TABLE><BR> 与之相对应的是,MFC 应用程序应使用AfxFreeLibrary
而非FreeLibrary 卸载MFC扩展DLL。AfxFreeLibrary的函数原型也与 FreeLibrary完全相同,为:<BR><BR>
<TABLE borderColor=#cccccc width="90%" align=center bgColor=#e3e3e3 border=1>
<TBODY>
<TR>
<TD>BOOL AFXAPI AfxFreeLibrary( HINSTANCE hInstLib
);</TD></TR></TBODY></TABLE><BR> 如果我们把上例中的“调用DLL”按钮单击事件的消息处理函数改为:<BR><BR>
<TABLE borderColor=#cccccc width="90%" align=center bgColor=#e3e3e3 border=1>
<TBODY>
<TR>
<TD>void CLoadExtDllDlg::OnDllcallButton() <BR>{<BR> HINSTANCE hDll =
AfxLoadLibrary( "ExtDll.dll" );<BR> if(NULL ==
hDll)<BR> {<BR> AfxMessageBox( "MFC扩展DLL动态加载失败"
);<BR> return;<BR> }<BR><BR> CExtDialog
extDialog;<BR> extDialog.DoModal();<BR> AfxFreeLibrary(hDll);<BR>}</TD></TR></TBODY></TABLE><BR> 则工程会出现link错误:<BR><BR>
<TABLE borderColor=#cccccc width="90%" align=center bgColor=#e3e3e3 border=1>
<TBODY>
<TR>
<TD>LoadExtDllDlg.obj : error LNK2001: unresolved external symbol
"__declspec(dllimport) public: virtual __thiscall
CExtDialog::~CExtDialog(void)"
(__imp_??1CExtDialog@@UAE@XZ)<BR><BR>LoadExtDllDlg.obj : error LNK2001:
unresolved external symbol "__declspec(dllimport) public: __thiscall
CExtDialog::CExtDialog(class CWnd *)"
(__imp_??0CExtDialog@@QAE@PAVCWnd@@@Z)</TD></TR></TBODY></TABLE><BR> 提示CExtDialog的构造函数和析构函数均无法找到!是的,对于派生MFC类的MFC扩展DLL,当我们要在应用程序中使用DLL中定义的派生类时,我们不宜使用动态加载DLL的方法。<BR><BR> <STRONG>6.4
MFC扩展DLL加载MFC扩展DLL</STRONG><BR><BR> 我们可以在MFC扩展DLL中再次使用MFC扩展DLL,但是,由于在两个DLL中对于AFX_EXT_CLASS、AFX_EXT_API、AFX_EXT_DATA宏的定义都是输出,这会导致调用的时候出现问题。<BR><BR> 我们将会在调用MFC扩展DLL的DLL中看到link错误:<BR><BR>
<TABLE borderColor=#cccccc width="90%" align=center bgColor=#e3e3e3 border=1>
<TBODY>
<TR>
<TD>error LNK2001: unresolved external symbol
….......</TD></TR></TBODY></TABLE><BR> 因此,在调用MFC扩展DLL的MFC扩展DLL中,在包含被调用DLL的头文件之前,需要临时重新定义AFX_EXT_CLASS的值。下面的例子显示了如何实现:<BR><BR>
<TABLE borderColor=#cccccc width="90%" align=center bgColor=#e3e3e3 border=1>
<TBODY>
<TR>
<TD>//临时改变宏的含义“输出”为“输入”<BR><BR>#undef AFX_EXT_CLASS<BR>#undef
AFX_EXT_API<BR>#undef AFX_EXT_DATA<BR>#define AFX_EXT_CLASS
AFX_CLASS_IMPORT<BR>#define AFX_EXT_API AFX_API_IMPORT<BR>#define
AFX_EXT_DATA AFX_DATA_IMPORT<BR><BR>//包含被调用MFC扩展DLL的头文件<BR><BR>#include
"CalledDLL.h"<BR><BR>//恢复宏的含义为输出<BR><BR>#undef AFX_EXT_CLASS<BR>#undef
AFX_EXT_API<BR>#undef AFX_EXT_DATA<BR>#define AFX_EXT_CLASS
AFX_CLASS_EXPORT<BR>#define AFX_EXT_API AFX_API_EXPORT<BR>#define
AFX_EXT_DATA AFX_DATA_EXPORT</TD></TR></TBODY></TABLE><BR>
<DIV class=right>共3页。 <A class=page
href="http://dev.yesky.com/359/2145859.shtml" target=_self><FONT
face=Webdings>9</FONT></A> <A class=page
href="http://dev.yesky.com/359/2145859.shtml" target=_self><FONT
face=Webdings>7</FONT></A> <A class=page
href="http://dev.yesky.com/359/2145859.shtml" target=_self><B>1</B></A> <A
class=page href="http://dev.yesky.com/359/2145859_1.shtml" target=_self><FONT
color=#666666><B>2</B></FONT></A> <A class=page
href="http://dev.yesky.com/359/2145859_2.shtml" target=_self><B>3</B></A> <A
class=page href="http://dev.yesky.com/359/2145859_2.shtml" target=_self><FONT
face=Webdings>8</FONT></A> <A class=page
href="http://dev.yesky.com/359/2145859_2.shtml" target=_self><FONT
face=Webdings>:</FONT></A></DIV></DIV><!--广告代码开始-->
<SCRIPT>
var ad_cid;
if (window.location.search.substring(1) != "")
{
ad_cid = window.location.search.substring(1);
} else {
ad_cid = 412;
}
</SCRIPT>
<!--小通栏:c-scolumn顶部500*90--><SPAN id=span_ad1>
<SCRIPT language=JavaScript>
document.write("<script src=\"http://vd.yesky.com/html/"+ad_cid+"/"+ad_cid+"_c-scolumn.js\"><\/script>");</SCRIPT>
</SPAN>
<SCRIPT language=JavaScript>
document.getElementById("ad1").innerHTML=document.getElementById("span_ad1").innerHTML;
document.getElementById("span_ad1").innerHTML="";
</SCRIPT>
<!--c-pip文章正文中间240*200--><SPAN id=span_ad3>
<SCRIPT language=JavaScript>
document.write("<script src=\"http://vd.yesky.com/html/"+ad_cid+"/"+ad_cid+"_c-pip.js\"><\/script>");</SCRIPT>
</SPAN>
<SCRIPT>
if(document.getElementById("contentAdv")) {
document.getElementById("contentAdv").innerHTML=document.getElementById("span_ad3").innerHTML;
document.getElementById("span_ad3").innerHTML="";
} else {
document.getElementById("ad3").innerHTML=document.getElementById("span_ad3").innerHTML;
document.getElementById("span_ad3").innerHTML="";
}</SCRIPT>
<!--c-text-1“您现在的位置”右侧文字--><SPAN id=span_ad2>
<SCRIPT language=JavaScript>
document.write("<script src=\"http://vd.yesky.com/html/"+ad_cid+"/"+ad_cid+"_c-text-1.js\"><\/script>");</SCRIPT>
</SPAN>
<SCRIPT language=JavaScript>
document.getElementById("ad2").innerHTML=document.getElementById("span_ad2").innerHTML;
document.getElementById("span_ad2").innerHTML="";
</SCRIPT>
<!--c-column-2“标题”上面的广告--><SPAN id=span_ad10>
<SCRIPT language=JavaScript>
document.write("<script src=\"http://vd.yesky.com/html/"+ad_cid+"/"+ad_cid+"_c-column-2.js\"><\/script>");</SCRIPT>
</SPAN>
<SCRIPT language=JavaScript>
document.getElementById("ad10").innerHTML=document.getElementById("span_ad10").innerHTML;
document.getElementById("span_ad10").innerHTML="";
</SCRIPT>
<!--c-column-1“摘要”下面的广告--><SPAN id=span_ad9>
<DIV id=ad9ad>
<SCRIPT language=JavaScript>
document.write("<script src=\"http://vd.yesky.com/html/"+ad_cid+"/"+ad_cid+"_c-column-1.js\"><\/script>");</SCRIPT>
</DIV></SPAN>
<SCRIPT language=JavaScript>
document.getElementById("ad9").innerHTML=document.getElementById("span_ad9").innerHTML;
document.getElementById("span_ad9").innerHTML="";
</SCRIPT>
<!--广告代码结束-->
<DIV id=ad7ad><SPAN id=ad7></SPAN></DIV>
<DIV class=clear></DIV>
<DIV id=conlink>
<SCRIPT type=text/javascript>var clipBoardContent = document.URL; function copyUserHomeToClipBoard() { window.clipboardData.setData("Text",clipBoardContent); alert("复制成功,请粘贴到你的QQ/MSN上推荐给你的好友!\r\n\r\n内容如下:\r\n" + clipBoardContent); }</SCRIPT>
<FORM id=feedbackForm name=feedbackForm
action=http://feedback.yesky.com/reader/user/doWelcome.view target=_blank><INPUT
id=refurl type=hidden name=refurl> <INPUT id=reftitle type=hidden name=reftitle>
</FORM>
<SCRIPT type=text/javascript>document.write("<a href=\"http:\/\/dig.yesky.com\" id=\'yeskyDig\' onclick=\"javascript:this.href=\'http:\/\/dig.yesky.com\/ding.php?t=\'+encodeURIComponent(document.title)+\'&u=\'+escape(document.location.href)+\'&ac=ding\';\" target=_blank title=\"此文不错,我顶!\"><b>我顶一下<\/b><\/a> <a onclick='javascript:submitFeedback();' style='cursor:hand;'><font color='#FF0000'><b>我要挑错</b></font></a> <a href=\"#top\" target=\"_self\"><a href=\"javascript:d=document;t=d.selection?(d.selection.type!='None'?d.selection.createRange().text:''):(d.getSelection?d.getSelection():'');void(yesky=window.open('http://hot.yesky.com/dp.aspx?t='+escape(d.title)+'&u='+escape(d.location.href)+'&c='+escape(t)+'&st=2','_blank','scrollbars=no,width=400,height=480,left=75,top=20,status=no,resizable=yes'));yesky.focus();\"title=\"推荐到天极网摘 http://hot.yesky.com [鼠标划选本文摘要,然后点击本图片]\" target=\"_self\">收藏到天极收藏夹</a> <a href=\"JavaScript: copyUserHomeToClipBoard()\" target=\"_self\">复制链接发给好友</a> <a href=\"javascript:window.external.AddFavorite('"+clipBoardContent+"')\" target=\"_self\">加入收藏</a> <a href=\"javascript:window.print()\" target=\"_self\">打印</a> <img src=\"http://image.yesky.com/TLimages/newmobile/titlebg19.gif\" title=\"返回顶部\"/></a>");function submitFeedback() { document.getElementById("refurl").value=document.location.href; document.getElementById("reftitle").value=document.title; document.getElementById("feedbackForm").submit();}</SCRIPT>
</DIV>
<DIV class=clear></DIV><!--评论-->
⌨️ 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 + -