c++ builder 程序设计实用教程 - 7_2 设计自己的数据库 - 张晋 - 17xie.htm

已经消失的不易找到的C++ builder网络教程总结

style="FONT-FAMILY: 宋体; mso-ascii-font-family: 'Times New Roman'; mso-hansi-font-family: 'Times New Roman'">方法；</SPAN></P>
<P class=MsoNormalIndent 
style="MARGIN-LEFT: 42.5pt; TEXT-INDENT: -21.25pt; mso-list: l1 level1 lfo2; tab-stops: list 42.25pt"><SPAN 
lang=EN-US 
style="FONT-FAMILY: Wingdings; mso-fareast-font-family: Wingdings; mso-bidi-font-family: Wingdings"><SPAN 
style="mso-list: Ignore">n<SPAN 
style="FONT: 7pt 'Times New Roman'">&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; 
</SPAN></SPAN></SPAN><SPAN lang=EN-US>ToBookMark</SPAN><SPAN 
style="FONT-FAMILY: 宋体; mso-ascii-font-family: 'Times New Roman'; mso-hansi-font-family: 'Times New Roman'">按钮：</SPAN><SPAN 
lang=EN-US>Table</SPAN><SPAN 
style="FONT-FAMILY: 宋体; mso-ascii-font-family: 'Times New Roman'; mso-hansi-font-family: 'Times New Roman'">控件的</SPAN><SPAN 
lang=EN-US>GotoBookmark</SPAN><SPAN 
style="FONT-FAMILY: 宋体; mso-ascii-font-family: 'Times New Roman'; mso-hansi-font-family: 'Times New Roman'">方法；</SPAN></P>
<P class=MsoNormalIndent 
style="MARGIN-LEFT: 42.5pt; TEXT-INDENT: -21.25pt; mso-list: l1 level1 lfo2; tab-stops: list 42.25pt"><SPAN 
lang=EN-US 
style="FONT-FAMILY: Wingdings; mso-fareast-font-family: Wingdings; mso-bidi-font-family: Wingdings"><SPAN 
style="mso-list: Ignore">n<SPAN 
style="FONT: 7pt 'Times New Roman'">&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; 
</SPAN></SPAN></SPAN><SPAN lang=EN-US>SetBookMark</SPAN><SPAN 
style="FONT-FAMILY: 宋体; mso-ascii-font-family: 'Times New Roman'; mso-hansi-font-family: 'Times New Roman'">按钮：</SPAN><SPAN 
lang=EN-US>Table</SPAN><SPAN 
style="FONT-FAMILY: 宋体; mso-ascii-font-family: 'Times New Roman'; mso-hansi-font-family: 'Times New Roman'">控件的</SPAN><SPAN 
lang=EN-US>GetBookmark</SPAN><SPAN 
style="FONT-FAMILY: 宋体; mso-ascii-font-family: 'Times New Roman'; mso-hansi-font-family: 'Times New Roman'">方法；</SPAN></P>
<P class=MsoNormalIndent 
style="MARGIN-LEFT: 42.5pt; TEXT-INDENT: -21.25pt; mso-list: l1 level1 lfo2; tab-stops: list 42.25pt"><SPAN 
lang=EN-US 
style="FONT-FAMILY: Wingdings; mso-fareast-font-family: Wingdings; mso-bidi-font-family: Wingdings"><SPAN 
style="mso-list: Ignore">n<SPAN 
style="FONT: 7pt 'Times New Roman'">&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; 
</SPAN></SPAN></SPAN><SPAN lang=EN-US>Close</SPAN><SPAN 
style="FONT-FAMILY: 宋体; mso-ascii-font-family: 'Times New Roman'; mso-hansi-font-family: 'Times New Roman'">按钮：</SPAN><SPAN 
lang=EN-US>Table</SPAN><SPAN 
style="FONT-FAMILY: 宋体; mso-ascii-font-family: 'Times New Roman'; mso-hansi-font-family: 'Times New Roman'">控件的</SPAN><SPAN 
lang=EN-US>Close</SPAN><SPAN 
style="FONT-FAMILY: 宋体; mso-ascii-font-family: 'Times New Roman'; mso-hansi-font-family: 'Times New Roman'">方法。</SPAN></P>
<H4><SPAN lang=EN-US>3</SPAN><SPAN 
style="FONT-FAMILY: 楷体_GB2312; mso-ascii-font-family: 'Times New Roman'">．响应计时器事件</SPAN></H4>
<P class=MsoNormalIndent><SPAN 
style="FONT-FAMILY: 宋体; mso-ascii-font-family: 'Times New Roman'; mso-hansi-font-family: 'Times New Roman'">窗体上添加的</SPAN><SPAN 
lang=EN-US>Timer</SPAN><SPAN 
style="FONT-FAMILY: 宋体; mso-ascii-font-family: 'Times New Roman'; mso-hansi-font-family: 'Times New Roman'">控件的作用是在程序运行的过程中动态的设置各个按钮控件的有效状态，例如在浏览或者编辑数据库中的数据时，如果当前的数据库指针已经移动到了数据库的开头或结尾，再执行</SPAN><SPAN 
lang=EN-US>Tabel</SPAN><SPAN 
style="FONT-FAMILY: 宋体; mso-ascii-font-family: 'Times New Roman'; mso-hansi-font-family: 'Times New Roman'">控件的</SPAN><SPAN 
lang=EN-US>Last</SPAN><SPAN 
style="FONT-FAMILY: 宋体; mso-ascii-font-family: 'Times New Roman'; mso-hansi-font-family: 'Times New Roman'">方法、</SPAN><SPAN 
lang=EN-US>Next</SPAN><SPAN 
style="FONT-FAMILY: 宋体; mso-ascii-font-family: 'Times New Roman'; mso-hansi-font-family: 'Times New Roman'">方法、</SPAN><SPAN 
lang=EN-US>First</SPAN><SPAN 
style="FONT-FAMILY: 宋体; mso-ascii-font-family: 'Times New Roman'; mso-hansi-font-family: 'Times New Roman'">方法和</SPAN><SPAN 
lang=EN-US>Prior</SPAN><SPAN 
style="FONT-FAMILY: 宋体; mso-ascii-font-family: 'Times New Roman'; mso-hansi-font-family: 'Times New Roman'">方法，程序就会出现运行错误。</SPAN></P>
<P class=MsoNormalIndent><SPAN 
style="FONT-FAMILY: 宋体; mso-ascii-font-family: 'Times New Roman'; mso-hansi-font-family: 'Times New Roman'">为了在程序运行的过程中避免以上错误的出现，在程序中应该有设置各个按钮有效状态的代码，为此，在程序设计的过程中，用鼠标的左键双击窗体上的</SPAN><SPAN 
lang=EN-US>Timer</SPAN><SPAN 
style="FONT-FAMILY: 宋体; mso-ascii-font-family: 'Times New Roman'; mso-hansi-font-family: 'Times New Roman'">控件，在屏幕上就会弹出一个代码窗口，在其中可以添加动态设置按钮有效状态的代码。</SPAN></P>
<P class=a1><SPAN lang=EN-US style="FONT-FAMILY: 'Times New Roman'">void 
__fastcall TForm1::Timer1Timer(TObject *Sender)<o:p></o:p></SPAN></P>
<P class=a1><SPAN lang=EN-US 
style="FONT-FAMILY: 'Times New Roman'">{<o:p></o:p></SPAN></P>
<P class=a1><SPAN lang=EN-US style="FONT-FAMILY: 'Times New Roman'">if 
(Form1-&gt;Table1-&gt;Eof)<o:p></o:p></SPAN></P>
<P class=a1><SPAN lang=EN-US style="FONT-FAMILY: 'Times New Roman'"><SPAN 
style="mso-spacerun: yes">&nbsp;&nbsp; </SPAN>{<o:p></o:p></SPAN></P>
<P class=a1><SPAN lang=EN-US style="FONT-FAMILY: 'Times New Roman'"><SPAN 
style="mso-spacerun: yes">&nbsp;&nbsp; 
</SPAN>Form1-&gt;Button4-&gt;Enabled=false;<o:p></o:p></SPAN></P>
<P class=a1><SPAN lang=EN-US style="FONT-FAMILY: 'Times New Roman'"><SPAN 
style="mso-spacerun: yes">&nbsp;&nbsp; 
</SPAN>Form1-&gt;Button3-&gt;Enabled=false;<o:p></o:p></SPAN></P>
<P class=a1><SPAN lang=EN-US style="FONT-FAMILY: 'Times New Roman'"><SPAN 
style="mso-spacerun: yes">&nbsp;&nbsp; </SPAN>}<o:p></o:p></SPAN></P>
<P class=a1><SPAN lang=EN-US style="FONT-FAMILY: 'Times New Roman'"><SPAN 
style="mso-spacerun: yes">&nbsp;&nbsp; </SPAN>else<o:p></o:p></SPAN></P>
<P class=a1><SPAN lang=EN-US style="FONT-FAMILY: 'Times New Roman'"><SPAN 
style="mso-spacerun: yes">&nbsp;&nbsp; </SPAN>{<o:p></o:p></SPAN></P>
<P class=a1><SPAN lang=EN-US style="FONT-FAMILY: 'Times New Roman'"><SPAN 
style="mso-spacerun: yes">&nbsp;&nbsp; 
</SPAN>Form1-&gt;Button4-&gt;Enabled=true;<o:p></o:p></SPAN></P>
<P class=a1><SPAN lang=EN-US style="FONT-FAMILY: 'Times New Roman'"><SPAN 
style="mso-spacerun: yes">&nbsp;&nbsp; 
</SPAN>Form1-&gt;Button3-&gt;Enabled=true;<o:p></o:p></SPAN></P>
<P class=a1><SPAN lang=EN-US style="FONT-FAMILY: 'Times New Roman'"><SPAN 
style="mso-spacerun: yes">&nbsp;&nbsp; </SPAN>}<o:p></o:p></SPAN></P>
<P class=a1><SPAN lang=EN-US style="FONT-FAMILY: 'Times New Roman'"><SPAN 
style="mso-spacerun: yes">&nbsp;&nbsp; </SPAN>//</SPAN><SPAN 
style="FONT-FAMILY: 宋体; mso-ascii-font-family: 'Times New Roman'; mso-hansi-font-family: 'Times New Roman'">动态设置“</SPAN><SPAN 
lang=EN-US style="FONT-FAMILY: 'Times New Roman'">Next</SPAN><SPAN 
style="FONT-FAMILY: 宋体; mso-ascii-font-family: 'Times New Roman'; mso-hansi-font-family: 'Times New Roman'">”和“</SPAN><SPAN 
lang=EN-US style="FONT-FAMILY: 'Times New Roman'">Last</SPAN><SPAN 
style="FONT-FAMILY: 宋体; mso-ascii-font-family: 'Times New Roman'; mso-hansi-font-family: 'Times New Roman'">”按钮的有效状态</SPAN><SPAN 
lang=EN-US style="FONT-FAMILY: 'Times New Roman'"><o:p></o:p></SPAN></P>
<P class=a1><SPAN lang=EN-US style="FONT-FAMILY: 'Times New Roman'">if 
(Form1-&gt;Table1-&gt;Bof)<o:p></o:p></SPAN></P>
<P class=a1><SPAN lang=EN-US style="FONT-FAMILY: 'Times New Roman'"><SPAN 
style="mso-spacerun: yes">&nbsp;&nbsp; </SPAN>{<o:p></o:p></SPAN></P>
<P class=a1><SPAN lang=EN-US style="FONT-FAMILY: 'Times New Roman'"><SPAN 
style="mso-spacerun: yes">&nbsp;&nbsp; 
</SPAN>Form1-&gt;Button1-&gt;Enabled=false;<o:p></o:p></SPAN></P>
<P class=a1><SPAN lang=EN-US style="FONT-FAMILY: 'Times New Roman'"><SPAN 
style="mso-spacerun: yes">&nbsp;&nbsp; 
</SPAN>Form1-&gt;Button2-&gt;Enabled=false;<o:p></o:p></SPAN></P>
<P class=a1><SPAN lang=EN-US style="FONT-FAMILY: 'Times New Roman'"><SPAN 
style="mso-spacerun: yes">&nbsp;&nbsp; </SPAN>}<o:p></o:p></SPAN></P>
<P class=a1><SPAN lang=EN-US style="FONT-FAMILY: 'Times New Roman'"><SPAN 
style="mso-spacerun: yes">&nbsp;&nbsp; </SPAN>else<o:p></o:p></SPAN></P>
<P class=a1><SPAN lang=EN-US style="FONT-FAMILY: 'Times New Roman'"><SPAN 
style="mso-spacerun: yes">&nbsp;&nbsp; </SPAN>{<o:p></o:p></SPAN></P>
<P class=a1><SPAN lang=EN-US style="FONT-FAMILY: 'Times New Roman'"><SPAN 
style="mso-spacerun: yes">&nbsp;&nbsp; 
</SPAN>Form1-&gt;Button1-&gt;Enabled=true;<o:p></o:p></SPAN></P>
<P class=a1><SPAN lang=EN-US style="FONT-FAMILY: 'Times New Roman'"><SPAN 
style="mso-spacerun: yes">&nbsp;&nbsp; 
</SPAN>Form1-&gt;Button2-&gt;Enabled=true;<o:p></o:p></SPAN></P>
<P class=a1><SPAN lang=EN-US style="FONT-FAMILY: 'Times New Roman'"><SPAN 
style="mso-spacerun: yes">&nbsp;&nbsp; </SPAN>}<o:p></o:p></SPAN></P>
<P class=a1><SPAN lang=EN-US style="FONT-FAMILY: 'Times New Roman'"><SPAN 
style="mso-spacerun: yes">&nbsp;&nbsp; </SPAN>//</SPAN><SPAN 
style="FONT-FAMILY: 宋体; mso-ascii-font-family: 'Times New Roman'; mso-hansi-font-family: 'Times New Roman'">动态设置“</SPAN><SPAN 
lang=EN-US style="FONT-FAMILY: 'Times New Roman'">First</SPAN><SPAN 
style="FONT-FAMILY: 宋体; mso-ascii-font-family: 'Times New Roman'; mso-hansi-font-family: 'Times New Roman'">”和“</SPAN><SPAN 
lang=EN-US style="FONT-FAMILY: 'Times New Roman'">Prior</SPAN><SPAN 
style="FONT-FAMILY: 宋体; mso-ascii-font-family: 'Times New Roman'; mso-hansi-font-family: 'Times New Roman'">”按钮的有效状态</SPAN><SPAN 
lang=EN-US style="FONT-FAMILY: 'Times New Roman'"><o:p></o:p></SPAN></P>
<P class=a1><SPAN lang=EN-US 
style="FONT-FAMILY: 'Times New Roman'">}<o:p></o:p></SPAN></P>
<P class=a1><SPAN lang=EN-US 
style="FONT-FAMILY: 'Times New Roman'">//-----------------------------------------------------------------------<o:p></o:p></SPAN></P>
<P class=MsoNormalIndent><SPAN 
style="FONT-FAMILY: 宋体; mso-ascii-font-family: 'Times New Roman'; mso-hansi-font-family: 'Times New Roman'">程序说明：</SPAN></P>
<P class=MsoNormalIndent><SPAN lang=EN-US>Timer</SPAN><SPAN 
style="FONT-FAMILY: 宋体; mso-ascii-font-family: 'Times New Roman'; mso-hansi-font-family: 'Times New Roman'">控件的</SPAN><SPAN 
lang=EN-US>Interval</SPAN><SPAN 
style="FONT-FAMILY: 宋体; mso-ascii-font-family: 'Times New Roman'; mso-hansi-font-family: 'Times New Roman'">属性设置为</SPAN><SPAN 
lang=EN-US>100</SPAN><SPAN 
style="FONT-FAMILY: 宋体; mso-ascii-font-family: 'Times New Roman'; mso-hansi-font-family: 'Times New Roman'">，即在程序的运行过程中，每隔</SPAN><SPAN 
lang=EN-US>100</SPAN><SPAN 
style="FONT-FAMILY: 宋体; mso-ascii-font-family: 'Times New Roman'; mso-hansi-font-family: 'Times New Roman'">微秒就会自动的激活一个</SPAN><SPAN 
lang=EN-US>Timer1Timer()</SPAN><SPAN 
style="FONT-FAMILY: 宋体; mso-ascii-font-family: 'Times New Roman'; mso-hansi-font-family: 'Times New Roman'">事件，随时的检测数据库文件指针的位置，同时设置按钮的有效状态，结果如图</SPAN><SPAN 
lang=EN-US>7-11</SPAN><SPAN 
style="FONT-FAMILY: 宋体; mso-ascii-font-family: 'Times New Roman'; mso-hansi-font-family: 'Times New Roman'">所示。</SPAN></P>
<P class=a><SPAN lang=EN-US><IMG height=197 
src="C++ Builder 程序设计实用教程 - 7_2 设计自己的数据库 - 张晋 - 17xie.files/0665e131c1.jpg" 
width=319 v:shapes="_x0000_i1027"></SPAN></P>
<P class=MsoCaption><SPAN 
style="FONT-FAMILY: 宋体; mso-ascii-font-family: 'Times New Roman'; mso-hansi-font-family: 'Times New Roman'">图</SPAN><SPAN 
lang=EN-US>7-11<SPAN style="mso-spacerun: yes">&nbsp; </SPAN></SPAN><SPAN 
style="FONT-FAMILY: 宋体; mso-ascii-font-family: 'Times New Roman'; mso-hansi-font-family: 'Times New Roman'">动态设置按钮有效状态</SPAN></P>
<H4><SPAN lang=EN-US>4</SPAN><SPAN 
style="FONT-FAMILY: 楷体_GB2312; mso-ascii-font-family: 'Times New Roman'">．运行程序</SPAN></H4>
<P class=MsoNormalIndent><SPAN 
style="FONT-FAMILY: 宋体; mso-ascii-font-family: 'Times New Roman'; mso-hansi-font-family: 'Times New Roman'">按照附后的源程序，添加剩余的程序代码后。做完以上的工作后，用鼠标选择菜单</SPAN><SPAN 
lang=EN-US>File</SPAN><SPAN 
style="FONT-FAMILY: 宋体; mso-ascii-font-family: 'Times New Roman'; mso-hansi-font-family: 'Times New Roman'">中的</SPAN><SPAN 
lang=EN-US>Save All</SPAN><SPAN 
style="FONT-FAMILY: 宋体; mso-ascii-font-family: 'Times New Roman'; mso-hansi-font-family: 'Times New Roman'">选项，在弹出的对话框中选择合适的文件名保存文件，然后按键盘上的功能键</SPAN><SPAN 
lang=EN-US>F9</SPAN><SPAN 
style="FONT-FAMILY: 宋体; mso-ascii-font-family: 'Times New Roman'; mso-hansi-font-family: 'Times New Roman'">运行程序，程序运行的结果如图</SPAN><SPAN 
lang=EN-US>7-12</SPAN><SPAN 
style="FONT-FAMILY: 宋体; mso-ascii-font-family: 'Times New Roman'; mso-hansi-font-family: 'Times New Roman'">所示。</SPAN></P>
<P class=a><SPAN lang=EN-US><IMG height=198 
src="C++ Builder 程序设计实用教程 - 7_2 设计自己的数据库 - 张晋 - 17xie.files/6801a7f0a5.jpg" 
width=322 v:shapes="_x0000_i1028"></SPAN></P>
<P class=MsoCaption><SPAN 
style="FONT-FAMILY: 宋体; mso-ascii-font-family: 'Times New Roman'; mso-hansi-font-family: 'Times New Roman'">图</SPAN><SPAN 
lang=EN-US>7-12<SPAN style="mso-spacerun: yes">&nbsp; </SPAN></SPAN><SPAN 
style="FONT-FAMILY: 宋体; mso-ascii-font-family: 'Times New Roman'; mso-hansi-font-family: 'Times New Roman'">程序运行结果</SPAN></P>
<P class=MsoNormalIndent><SPAN 
style="FONT-FAMILY: 宋体; mso-ascii-font-family: 'Times New Roman'; mso-hansi-font-family: 'Times New Roman'">程序完整源代码如下所示：</SPAN></P>
<P class=MsoNormalIndent><SPAN lang=EN-US><o:p>&nbsp;</o:p></SPAN></P>
<DIV 
style="BORDER-RIGHT: windowtext 1pt solid; PADDING-RIGHT: 0cm; BORDER-TOP: windowtext 1pt solid; PADDING-LEFT: 0cm; PADDING-BOTTOM: 1pt; BORDER-LEFT: windowtext 1pt solid; PADDING-TOP: 1pt; BORDER-BOTTOM: windowtext 1pt solid; mso-border-alt: solid windowtext .5pt; mso-element: para-border-div">
<P class=a0 
style="BORDER-RIGHT: medium none; PADDING-RIGHT: 0cm; BORDER-TOP: medium none; PADDING-LEFT: 0cm; PADDING-BOTTOM: 0cm; BORDER-LEFT: medium none; PADDING-TOP: 0cm; BORDER-BOTTOM: medium none; mso-border-alt: solid windowtext .5pt; mso-padding-alt: 1.0pt 0cm 1.0pt 0cm"><SPAN 
style="FONT-FAMILY: 仿宋_GB2312; mso-ascii-font-family: 'Times New Roman