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<p class=MsoNormal><span style='font-family:宋体'>数据库中提供了</span><span lang=EN-US>20</span><span
style='font-family:宋体'>条记录。</span></p>
<p class=MsoNormal><span lang=EN-US>(3) </span><span style='font-family:宋体'>事件</span></p>
<p class=MsoNormal><span lang=EN-US>Events</span><span style='font-family:宋体'>表包含表</span><span
lang=EN-US>25-5</span><span style='font-family:宋体'>所示的列。</span></p>
<p class=a5 style='margin-top:3.25pt'><span style='font-family:黑体'>表</span><span
lang=EN-US> 25-5</span></p>
<div align=center>
<table class=MsoNormalTable border=1 cellspacing=0 cellpadding=0 width=582
style='width:436.3pt;border-collapse:collapse;border:none'>
<tr>
<td width=147 valign=top style='width:110.3pt;border:solid windowtext 1.0pt;
border-left:none;padding:0cm 9.9pt 0cm 9.9pt'>
<p class=a2><span style='font-family:黑体'>列</span></p>
</td>
<td width=189 valign=top style='width:5.0cm;border:solid windowtext 1.0pt;
border-left:none;padding:0cm 9.9pt 0cm 9.9pt'>
<p class=a2><span style='font-family:黑体'>类</span><span lang=EN-US>
</span><span style='font-family:黑体'>型</span></p>
</td>
<td width=246 valign=top style='width:184.25pt;border-top:solid windowtext 1.0pt;
border-left:none;border-bottom:solid windowtext 1.0pt;border-right:none;
padding:0cm 9.9pt 0cm 9.9pt'>
<p class=a2><span style='font-family:黑体'>说</span><span lang=EN-US>
</span><span style='font-family:黑体'>明</span></p>
</td>
</tr>
<tr>
<td width=147 valign=top style='width:110.3pt;border-top:none;border-left:
none;border-bottom:solid windowtext 1.0pt;border-right:solid windowtext 1.0pt;
padding:0cm 9.9pt 0cm 9.9pt'>
<p class=a4 style='margin-left:10.7pt'><span lang=EN-US>ID</span></p>
</td>
<td width=189 valign=top style='width:5.0cm;border-top:none;border-left:none;
border-bottom:solid windowtext 1.0pt;border-right:solid windowtext 1.0pt;
padding:0cm 9.9pt 0cm 9.9pt'>
<p class=a4 style='margin-left:10.7pt'><span lang=EN-US>AutoNumber</span><span
style='font-family:宋体'>，主键</span></p>
</td>
<td width=246 valign=top style='width:184.25pt;border:none;border-bottom:
solid windowtext 1.0pt;padding:0cm 9.9pt 0cm 9.9pt'>
<p class=a4 style='margin-left:10.7pt'><span style='font-family:宋体'>会议标识号码</span></p>
</td>
</tr>
<tr>
<td width=147 valign=top style='width:110.3pt;border-top:none;border-left:
none;border-bottom:solid windowtext 1.0pt;border-right:solid windowtext 1.0pt;
padding:0cm 9.9pt 0cm 9.9pt'>
<p class=a4 style='margin-left:10.7pt'><span lang=EN-US>Name</span></p>
</td>
<td width=189 valign=top style='width:5.0cm;border-top:none;border-left:none;
border-bottom:solid windowtext 1.0pt;border-right:solid windowtext 1.0pt;
padding:0cm 9.9pt 0cm 9.9pt'>
<p class=a4 style='margin-left:10.7pt'><span lang=EN-US>Text</span><span
style='font-family:宋体'>，必选，</span><span lang=EN-US>255</span><span
style='font-family:宋体'>个字符</span><span lang=EN-US> </span></p>
</td>
<td width=246 valign=top style='width:184.25pt;border:none;border-bottom:
solid windowtext 1.0pt;padding:0cm 9.9pt 0cm 9.9pt'>
<p class=a4 style='margin-left:10.7pt'><span style='font-family:宋体'>会议名称</span></p>
</td>
</tr>
<tr>
<td width=147 valign=top style='width:110.3pt;border-top:none;border-left:
none;border-bottom:solid windowtext 1.0pt;border-right:solid windowtext 1.0pt;
padding:0cm 9.9pt 0cm 9.9pt'>
<p class=a4 style='margin-left:10.7pt'><span lang=EN-US>Room</span></p>
</td>
<td width=189 valign=top style='width:5.0cm;border-top:none;border-left:none;
border-bottom:solid windowtext 1.0pt;border-right:solid windowtext 1.0pt;
padding:0cm 9.9pt 0cm 9.9pt'>
<p class=a4 style='margin-left:10.7pt'><span lang=EN-US>Number</span><span
style='font-family:宋体'>，必选</span></p>
</td>
<td width=246 valign=top style='width:184.25pt;border:none;border-bottom:
solid windowtext 1.0pt;padding:0cm 9.9pt 0cm 9.9pt'>
<p class=a4 style='margin-left:10.7pt'><span style='font-family:宋体'>会议室</span><span
lang=EN-US>ID.</span></p>
</td>
</tr>
<tr>
<td width=147 valign=top style='width:110.3pt;border-top:none;border-left:
none;border-bottom:solid windowtext 1.0pt;border-right:solid windowtext 1.0pt;
padding:0cm 9.9pt 0cm 9.9pt'>
<p class=a4 style='margin-left:10.7pt'><span lang=EN-US>AttendeeList</span></p>
</td>
<td width=189 valign=top style='width:5.0cm;border-top:none;border-left:none;
border-bottom:solid windowtext 1.0pt;border-right:solid windowtext 1.0pt;
padding:0cm 9.9pt 0cm 9.9pt'>
<p class=a4 style='margin-left:10.7pt'><span lang=EN-US>Memo</span><span
style='font-family:宋体'>，必选</span></p>
</td>
<td width=246 valign=top style='width:184.25pt;border:none;border-bottom:
solid windowtext 1.0pt;padding:0cm 9.9pt 0cm 9.9pt'>
<p class=a4 style='margin-left:10.7pt'><span style='font-family:宋体'>参加者姓名列表</span></p>
</td>
</tr>
<tr>
<td width=147 valign=top style='width:110.3pt;border-top:none;border-left:
none;border-bottom:solid windowtext 1.0pt;border-right:solid windowtext 1.0pt;
padding:0cm 9.9pt 0cm 9.9pt'>
<p class=a4 style='margin-left:10.7pt'><span lang=EN-US>EventData</span></p>
</td>
<td width=189 valign=top style='width:5.0cm;border-top:none;border-left:none;
border-bottom:solid windowtext 1.0pt;border-right:solid windowtext 1.0pt;
padding:0cm 9.9pt 0cm 9.9pt'>
<p class=a4 style='margin-left:10.7pt'><span lang=EN-US>Date/Time</span><span
style='font-family:宋体'>，必选</span></p>
</td>
<td width=246 valign=top style='width:184.25pt;border:none;border-bottom:
solid windowtext 1.0pt;padding:0cm 9.9pt 0cm 9.9pt'>
<p class=a4 style='margin-left:10.7pt'><span style='font-family:宋体'>会议日期</span></p>
</td>
</tr>
</table>
</div>
<p class=MsoNormal><span style='font-family:宋体'>下载的数据库中提供了几个会议。</span></p>
<h4 style='FTEL:21.45pt'><span lang=EN-US>2. </span><span
style='font-family:黑体'>数据库的绑定</span></h4>
<p class=MsoNormal><span style='font-family:宋体'>要绑定数据的两个控件是</span><span
lang=EN-US>attendeeList </span><span style='font-family:宋体'>和</span><span
lang=EN-US> roomList</span><span style='font-family:宋体'>。为了做到这一点，必须把这些控件的</span><span
lang=EN-US>DataSource</span><span style='font-family:宋体'>属性设置为包含数据的表格。代码必须把数据加载到这些表格中，在运行期间执行这个绑定。这两个控件都有</span><span
lang=EN-US>DataTextField </span><span style='font-family:宋体'>和</span><span
lang=EN-US> DataValueField</span><span style='font-family:宋体'>属性，指定要使用哪些列来分别显示列表项目和设置</span><span
lang=EN-US>value</span><span style='font-family:宋体'>属性。在这两种情况下，可以在设计期间设置这些属性，只要</span><span
lang=EN-US>DataSource</span><span style='font-family:宋体'>属性设置为在控件中填充列表项目，就可以使用这两个属性。</span></p>
<p class=MsoNormal><span style='font-family:宋体'>在</span><span lang=EN-US>ASP.NET</span><span
style='font-family:宋体'>代码中，删除这些控件的现有项目，则其声明如下所示：</span></p>
<p class=a6 style='margin-top:8.15pt;margin-right:0cm;FTEL:0cm;
margin-left:21.45pt;FTEL:.0001pt;FTEL:18.45pt'><span
lang=EN-US>
...</span></p>
<p class=a6 style='margin-left:21.45pt;FTEL:18.45pt'><span lang=EN-US>
<asp:DropDownList ID="roomList" Runat="server" </span></p>
<p class=2 style='margin-left:21.45pt;FTEL:18.45pt'><span lang=EN-US>
Width="160px" DataTextField="Room" </span></p>
<p class=2 style='margin-left:21.45pt;FTEL:18.45pt'><span lang=EN-US>
DataValueField="ID" ></asp:DropDownList></span></p>
<p class=a6 style='margin-left:21.45pt;FTEL:18.45pt'><span lang=EN-US>
...</span></p>
<p class=2 style='margin-left:21.45pt;FTEL:18.45pt'><span lang=EN-US>
<asp:ListBox ID="attendeeList" Runat="server"
Width="160px"</span></p>
<p class=2 style='margin-left:21.45pt;FTEL:18.45pt'><span lang=EN-US>
SelectionMode="Multiple" Rows="6" </span></p>
<p class=2 style='margin-left:21.45pt;FTEL:18.45pt'><span lang=EN-US>
DataTextField="Name" DataValueField="ID"
/></asp:ListBox></span></p>
<p class=a6 style='margin-top:0cm;margin-right:0cm;FTEL:8.15pt;
margin-left:21.45pt;FTEL:18.45pt'><span lang=EN-US>
...</span></p>
<p class=MsoNormal><span style='font-family:宋体'>下一个任务是创建数据库连接。这可以使用几种方式，如前面第</span><span
lang=EN-US>21</span><span style='font-family:宋体'>章中所述。我们采用手工编码的方式，使该任务简单一些。因为使用的是</span><span
lang=EN-US>Access</span><span style='font-family:宋体'>，这个连接的提供者类型是</span><span
lang=EN-US>Microsoft Jet 4.0 OLE DB Provider</span><span style='font-family:
宋体'>。所以在窗体上添加一个</span><span lang=EN-US>Data.OleDb.OleDbConnection</span><span
style='font-family:宋体'>对象</span><span lang=EN-US>oleDbConnection1</span><span
style='font-family:宋体'>：</span></p>
<p class=a6 style='margin-top:8.15pt;margin-right:0cm;FTEL:0cm;
margin-left:21.45pt;FTEL:.0001pt;FTEL:18.45pt'><span
lang=EN-US> public class WebForm1 : System.Web.UI.Page</span></p>
<p class=a6 style='margin-left:21.45pt;FTEL:18.45pt'><span lang=EN-US>
{</span></p>
<p class=a6 style='margin-left:21.45pt;FTEL:18.45pt'><span lang=EN-US>
...</span><span class=MsoCommentReference><span lang=EN-US style='font-size:
8.0pt;font-family:"Baskerville BE Regular";display:none;letter-spacing:.2pt'> </span></span></p>
<p class=2 style='margin-top:0cm;margin-right:0cm;FTEL:8.15pt;
margin-left:21.45pt;FTEL:18.45pt'><span lang=EN-US>
protected System.Data.OleDb.OleDbConnection oleDbConnection1;</span></p>
<p class=a3 style='margin-top:8.15pt;FTEL:21.45pt'><span
style='font-family:黑体'>提示：</span></p>
<p class=a1 style='FTEL:8.15pt;FTEL:21.45pt'><span
style='font-family:楷体_GB2312'>对于</span><span lang=EN-US>SQL Server</span><span
style='font-family:楷体_GB2312'>连接，添加的是一个</span><span lang=EN-US>SqlClient.SqlConnection</span><span
style='font-family:楷体_GB2312'>对象。</span></p>
<p class=MsoNormal><span style='font-family:宋体'>然后需要把一些代码添加到</span><span
lang=EN-US>InitializeComponent()</span><span style='font-family:宋体'>中，设置</span><span
lang=EN-US>oleDbConnection1</span><span style='font-family:宋体'>的</span><span
lang=EN-US>Connection String</span><span style='font-family:宋体'>属性，以便在代码中使用：</span></p>
<p class=a6 style='margin-top:8.15pt;margin-right:0cm;FTEL:0cm;
margin-left:21.45pt;FTEL:.0001pt;FTEL:18.45pt'><span
lang=EN-US> private void InitializeComponent()</span></p>
<p class=a6 style='margin-left:21.45pt;FTEL:18.45pt'><span lang=EN-US>
{</span></p>
<p class=2 style='margin-left:21.45pt;FTEL:18.45pt'><span lang=EN-US>
this.oleDbConnection1 = new System.Data.OleDb.OleDbConnection();</span></p>
<p class=a6 style='margin-left:21.45pt;FTEL:18.45pt'><span lang=EN-US>
...</span></p>
<p class=2 style='margin-left:21.45pt;FTEL:18.45pt'><span lang=EN-US>
this.oleDbConnection1.ConnectionString = </span></p>
<p class=2 style='margin-left:21.45pt;FTEL:18.45pt'><span lang=EN-US>
@"Provider=Microsoft.Jet.OLEDB.4.0;Password="""";User
ID=Admin;Data " +</span></p>
<p class=2 style='margin-top:0cm;margin-right:0cm;FTEL:8.15pt;
margin-left:21.45pt;FTEL:18.45pt'><span lang=EN-US>
"Source=C:\\Inetpub\\wwwroot\\PCSWebApp3\\PCSWebApp3.mdb";</span></p>
<p class=MsoNormal><span style='font-family:宋体'>在</span><span lang=EN-US>Page_Load()</span><span
style='font-family:宋体'>事件处理程序中执行数据绑定，以便在其他部分使用这些控件时完全填充控件。无论是否在执行回送操作</span><span
lang=EN-US>(</span><span style='font-family:宋体'>即使列表控件通过</span><span
lang=EN-US>viewstate</span><span style='font-family:宋体'>保存它们的内容</span><span
lang=EN-US>)</span><span style='font-family:宋体'>，都将从数据库中读取数据，确保可以访问需要的数据，</span>
<span style='font-family:宋体'>但不需要在回送中执行数据绑定。这似乎是在浪费时间，但您可以练习把其他逻辑添加到代码中，优化这个行为。下面主要讨论如何进行工作，而没有考虑实际的细节。</span></p>
<p class=MsoNormal><span style='font-family:宋体'>所有的代码都放在连接对象的</span><span
lang=EN-US>Open() </span><span style='font-family:宋体'>和</span><span lang=EN-US>
Close()</span><span style='font-family:宋体'>方法调用之间。</span></p>
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