book_text6.htm

深入编程内幕vc++ 非常适合处学者学习

            style="FONT-SIZE: 10.5pt; FONT-FAMILY: 宋体; mso-bidi-font-size: 10.0pt; mso-hansi-font-family: 'MS Sans Serif'">图3.5<O:P> 
            </O:P></SPAN></P>
            <P class=MsoNormal 
            style="WORD-BREAK: break-all; TEXT-INDENT: 20pt; mso-line-height-alt: 1.3pt; mso-layout-grid-align: none; punctuation-wrap: simple"><SPAN 
            style="FONT-SIZE: 10.5pt; FONT-FAMILY: 宋体; mso-bidi-font-size: 10.0pt; mso-hansi-font-family: 'MS Sans Serif'">单击图<SPAN 
            lang=EN-US>3.5中所示</SPAN></SPAN><SPAN lang=EN-US 
            style="FONT-SIZE: 10.5pt; mso-bidi-font-size: 10.0pt">CHANGE</SPAN><SPAN 
            style="FONT-SIZE: 10.5pt; FONT-FAMILY: 宋体; mso-bidi-font-size: 10.0pt; mso-hansi-font-family: 'MS Sans Serif'">按钮，在</SPAN><SPAN 
            lang=EN-US 
            style="FONT-SIZE: 10.5pt; mso-bidi-font-size: 10.0pt">HEADER 
            FILE</SPAN><SPAN 
            style="FONT-SIZE: 10.5pt; FONT-FAMILY: 宋体; mso-bidi-font-size: 10.0pt; mso-hansi-font-family: 'MS Sans Serif'">和</SPAN><SPAN 
            lang=EN-US 
            style="FONT-SIZE: 10.5pt; mso-bidi-font-size: 10.0pt">IMPLEMENTATION 
            FILE</SPAN><SPAN 
            style="FONT-SIZE: 10.5pt; FONT-FAMILY: 宋体; mso-bidi-font-size: 10.0pt; mso-hansi-font-family: 'MS Sans Serif'">当中分别敲入</SPAN><SPAN 
            style="FONT-SIZE: 10.5pt; FONT-FAMILY: 宋体; mso-bidi-font-size: 10.0pt; mso-hansi-font-family: 'Times New Roman'; mso-ascii-font-family: 'Times New Roman'">新类的声明</SPAN><SPAN 
            style="FONT-SIZE: 10.5pt; FONT-FAMILY: 宋体; mso-bidi-font-size: 10.0pt; mso-hansi-font-family: 'MS Sans Serif'">和定义分别写在哪个文件当中，单击</SPAN><SPAN 
            lang=EN-US 
            style="FONT-SIZE: 10.5pt; mso-bidi-font-size: 10.0pt">OK</SPAN><SPAN 
            style="FONT-SIZE: 10.5pt; FONT-FAMILY: 宋体; mso-bidi-font-size: 10.0pt; mso-hansi-font-family: 'MS Sans Serif'">按钮确认，这样我们就完成了对新的对话框类的定义。单击</SPAN><SPAN 
            lang=EN-US style="FONT-SIZE: 10.5pt; mso-bidi-font-size: 10.0pt">OK 
            </SPAN><SPAN 
            style="FONT-SIZE: 10.5pt; FONT-FAMILY: 宋体; mso-bidi-font-size: 10.0pt; mso-hansi-font-family: 'MS Sans Serif'">按钮，</SPAN><SPAN 
            lang=EN-US 
            style="FONT-SIZE: 10.5pt; mso-bidi-font-size: 10.0pt">CLASS 
            WIZARD</SPAN><SPAN 
            style="FONT-SIZE: 10.5pt; FONT-FAMILY: 宋体; mso-bidi-font-size: 10.0pt; mso-hansi-font-family: 'MS Sans Serif'">将按照我们刚才的要求进行对话框类定义的工作。打开</SPAN><SPAN 
            lang=EN-US 
            style="FONT-SIZE: 10.5pt; mso-bidi-font-size: 10.0pt">WORKSPACE</SPAN><SPAN 
            style="FONT-SIZE: 10.5pt; FONT-FAMILY: 宋体; mso-bidi-font-size: 10.0pt; mso-hansi-font-family: 'Times New Roman'; mso-ascii-font-family: 'Times New Roman'">，</SPAN><SPAN 
            style="FONT-SIZE: 10.5pt; FONT-FAMILY: 宋体; mso-bidi-font-size: 10.0pt; mso-hansi-font-family: 'MS Sans Serif'">选择</SPAN><SPAN 
            lang=EN-US 
            style="FONT-SIZE: 10.5pt; mso-bidi-font-size: 10.0pt">FILE 
            VIEW</SPAN><SPAN 
            style="FONT-SIZE: 10.5pt; FONT-FAMILY: 宋体; mso-bidi-font-size: 10.0pt; mso-hansi-font-family: 'MS Sans Serif'">一页，在</SPAN><SPAN 
            lang=EN-US 
            style="FONT-SIZE: 10.5pt; mso-bidi-font-size: 10.0pt">SOURCE 
            FILES</SPAN><SPAN 
            style="FONT-SIZE: 10.5pt; FONT-FAMILY: 宋体; mso-bidi-font-size: 10.0pt; mso-hansi-font-family: 'MS Sans Serif'">和</SPAN><SPAN 
            lang=EN-US 
            style="FONT-SIZE: 10.5pt; mso-bidi-font-size: 10.0pt">HEADER 
            FILES</SPAN><SPAN 
            style="FONT-SIZE: 10.5pt; FONT-FAMILY: 宋体; mso-bidi-font-size: 10.0pt; mso-hansi-font-family: 'MS Sans Serif'">组当中到</SPAN><SPAN 
            lang=EN-US 
            style="FONT-SIZE: 10.5pt; mso-bidi-font-size: 10.0pt">CLASS 
            WIZARD</SPAN><SPAN 
            style="FONT-SIZE: 10.5pt; FONT-FAMILY: 宋体; mso-bidi-font-size: 10.0pt; mso-hansi-font-family: 'MS Sans Serif'">已经新建了两个文件，并将它们加入了工程当中。</SPAN><SPAN 
            lang=EN-US 
            style="FONT-SIZE: 10.5pt; mso-bidi-font-size: 10.0pt">SongDlg.h</SPAN><SPAN 
            style="FONT-SIZE: 10.5pt; FONT-FAMILY: 宋体; mso-bidi-font-size: 10.0pt; mso-hansi-font-family: 'MS Sans Serif'">当中内容是</SPAN><SPAN 
            lang=EN-US 
            style="FONT-SIZE: 10.5pt; mso-bidi-font-size: 10.0pt">CSongDlg</SPAN><SPAN 
            style="FONT-SIZE: 10.5pt; FONT-FAMILY: 宋体; mso-bidi-font-size: 10.0pt; mso-hansi-font-family: 'MS Sans Serif'">这个类的声明，</SPAN><SPAN 
            lang=EN-US 
            style="FONT-SIZE: 10.5pt; mso-bidi-font-size: 10.0pt">SongDlg.cpp</SPAN><SPAN 
            style="FONT-SIZE: 10.5pt; FONT-FAMILY: 宋体; mso-bidi-font-size: 10.0pt; mso-hansi-font-family: 'MS Sans Serif'">这个文件当中的内容是这个类的实现。但是目前的程序只是包含了实现一个对话框的最基本功能的代码，调用这个对话框类的</SPAN><SPAN 
            lang=EN-US 
            style="FONT-SIZE: 10.5pt; mso-bidi-font-size: 10.0pt">DoModal</SPAN><SPAN 
            style="FONT-SIZE: 10.5pt; FONT-FAMILY: 宋体; mso-bidi-font-size: 10.0pt; mso-hansi-font-family: 'MS Sans Serif'">函数之后可以运行它。但是用户通过对话框进行的所有的输入工作都不会被接受。</SPAN><SPAN 
            lang=EN-US 
            style="FONT-SIZE: 10.5pt; mso-bidi-font-size: 10.0pt"><O:P> 
            </O:P></SPAN></P>
            <P class=MsoBodyTextIndent3 
            style="mso-line-height-alt: 1.3pt; mso-layout-grid-align: none">&nbsp;&nbsp;&nbsp; 
            下面，我们就着手完成实现对话框接受用户输入功能的工作。这里核心的工作就是实现对布置在对话框当中的控件的控制。控制又可以分两种类型：第一种是与界面上的控件交换数据，在对话框中的某些响应函数当中编写取出用户在对话框当中输入的数据。比方说在用户单击了确认输入的按钮，触发了该按钮的单击事件的时候，我们就要从输入新歌的编辑框当中取出曲目字符串保存到数据库当中，并将其显示在曲目列表当中。</P>
            <P class=MsoNormal 
            style="WORD-BREAK: break-all; TEXT-INDENT: 20pt; mso-line-height-alt: 1.3pt; mso-layout-grid-align: none; punctuation-wrap: simple"><SPAN 
            style="FONT-SIZE: 10.5pt; FONT-FAMILY: 宋体; mso-bidi-font-size: 10.0pt; mso-hansi-font-family: 'MS Sans Serif'">我们可以使用</SPAN><SPAN 
            lang=EN-US 
            style="FONT-SIZE: 10.5pt; mso-bidi-font-size: 10.0pt">MFC</SPAN><SPAN 
            style="FONT-SIZE: 10.5pt; FONT-FAMILY: 宋体; mso-bidi-font-size: 10.0pt; mso-hansi-font-family: 'MS Sans Serif'">提供的一种叫做对话框数据交换（</SPAN><SPAN 
            lang=EN-US 
            style="FONT-SIZE: 10.5pt; mso-bidi-font-size: 10.0pt">DDX</SPAN><SPAN 
            style="FONT-SIZE: 10.5pt; FONT-FAMILY: 宋体; mso-bidi-font-size: 10.0pt; mso-hansi-font-family: 'MS Sans Serif'">）的机制来从编辑控件当中取出数据。在</SPAN><SPAN 
            lang=EN-US 
            style="FONT-SIZE: 10.5pt; mso-bidi-font-size: 10.0pt">MFC</SPAN><SPAN 
            style="FONT-SIZE: 10.5pt; FONT-FAMILY: 宋体; mso-bidi-font-size: 10.0pt; mso-hansi-font-family: 'MS Sans Serif'">的对话框类</SPAN><SPAN 
            lang=EN-US 
            style="FONT-SIZE: 10.5pt; mso-bidi-font-size: 10.0pt">CDialog</SPAN><SPAN 
            style="FONT-SIZE: 10.5pt; FONT-FAMILY: 宋体; mso-bidi-font-size: 10.0pt; mso-hansi-font-family: 'MS Sans Serif'">中已经封装了这种机制。它的工作原理就是在对话框资源中的编辑框和对话框类的一个成员变量之间建立连接。然后由<SPAN 
            lang=EN-US>MFC自动地完成在成员变量和控件之间的数据交换工作。首先打开</SPAN></SPAN><SPAN 
            lang=EN-US 
            style="FONT-SIZE: 10.5pt; mso-bidi-font-size: 10.0pt">CLASSWIZARD</SPAN><SPAN 
            style="FONT-SIZE: 10.5pt; FONT-FAMILY: 宋体; mso-bidi-font-size: 10.0pt; mso-hansi-font-family: 'Times New Roman'; mso-ascii-font-family: 'Times New Roman'">，选中</SPAN><SPAN 
            lang=EN-US 
            style="FONT-SIZE: 10.5pt; mso-bidi-font-size: 10.0pt">MEMBER 
            VARIABLE</SPAN><SPAN 
            style="FONT-SIZE: 10.5pt; FONT-FAMILY: 宋体; mso-bidi-font-size: 10.0pt; mso-hansi-font-family: 'MS Sans Serif'">这一页，在</SPAN><SPAN 
            lang=EN-US 
            style="FONT-SIZE: 10.5pt; mso-bidi-font-size: 10.0pt">CLASS 
            NAME</SPAN><SPAN 
            style="FONT-SIZE: 10.5pt; FONT-FAMILY: 宋体; mso-bidi-font-size: 10.0pt; mso-hansi-font-family: 'MS Sans Serif'">列表框当中选择</SPAN><SPAN 
            lang=EN-US 
            style="FONT-SIZE: 10.5pt; mso-bidi-font-size: 10.0pt">CSongDlg</SPAN><SPAN 
            style="FONT-SIZE: 10.5pt; FONT-FAMILY: 宋体; mso-bidi-font-size: 10.0pt; mso-hansi-font-family: 'Times New Roman'; mso-ascii-font-family: 'Times New Roman'">，选择曲目</SPAN><SPAN 
            style="FONT-SIZE: 10.5pt; FONT-FAMILY: 宋体; mso-bidi-font-size: 10.0pt; mso-hansi-font-family: 'MS Sans Serif'">编辑框的</SPAN><SPAN 
            lang=EN-US 
            style="FONT-SIZE: 10.5pt; mso-bidi-font-size: 10.0pt">ID</SPAN><SPAN 
            style="FONT-SIZE: 10.5pt; FONT-FAMILY: 宋体; mso-bidi-font-size: 10.0pt; mso-hansi-font-family: 'MS Sans Serif'">号</SPAN><SPAN 
            lang=EN-US 
            style="FONT-SIZE: 10.5pt; mso-bidi-font-size: 10.0pt">IDC_EDIT1</SPAN><SPAN 
            style="FONT-SIZE: 10.5pt; FONT-FAMILY: 宋体; mso-bidi-font-size: 10.0pt; mso-hansi-font-family: 'Times New Roman'; mso-ascii-font-family: 'Times New Roman'">，</SPAN><SPAN 
            style="FONT-SIZE: 10.5pt; FONT-FAMILY: 宋体; mso-bidi-font-size: 10.0pt; mso-hansi-font-family: 'MS Sans Serif'">单击</SPAN><SPAN 
            lang=EN-US style="FONT-SIZE: 10.5pt; mso-bidi-font-size: 10.0pt">ADD 
            VARIABLE</SPAN><SPAN 
            style="FONT-SIZE: 10.5pt; FONT-FAMILY: 宋体; mso-bidi-font-size: 10.0pt; mso-hansi-font-family: 'MS Sans Serif'">按钮。</SPAN></P>
            <P class=MsoNormal 
            style="WORD-BREAK: break-all; TEXT-INDENT: 20pt; mso-line-height-alt: 1.3pt; mso-layout-grid-align: none; punctuation-wrap: simple" 
            align=center><SPAN style="mso-ignore: vglayout"><IMG height=286 
            src="book_text6.files/book_t6.jpg" width=439 
            v:shapes="_x0000_s1031"></SPAN><BR><SPAN 
            style="FONT-SIZE: 10.5pt; FONT-FAMILY: 宋体; mso-bidi-font-size: 10.0pt; mso-hansi-font-family: 'MS Sans Serif'">图<SPAN 
            lang=EN-US>3.6<O:P> </O:P></SPAN></SPAN></P>