100165684.htm
来自「C#高级编程(第三版),顶死你们。。 。up」· HTM 代码 · 共 747 行 · 第 1/3 页
HTM
747 行
<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 Page_Load(object sender,
System.EventArgs e)</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>
oleDbConnection1.Open();</span></p>
<p class=a6 style='margin-left:21.45pt;FTEL:18.45pt'><span lang=EN-US>
if (!this.IsPostBack)</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>
calendar.SelectedDate = System.DateTime.Now;</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>
oleDbConnection1.Close();</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'>下面说明为什么日历的日期设置放在回送检查代码中。</span></p>
<p class=MsoNormal><span style='font-family:宋体'>对于数据交换，需要使用几个对象来存储数据。可以在类级别上声明这些对象，以便在其他函数中访问它们。需要一个</span><span
lang=EN-US>DataSet</span><span style='font-family:宋体'>对象存储数据库信息，三个</span><span
lang=EN-US>OleDb.OleDbDataAdapter</span><span style='font-family:宋体'>对象执行数据集上的查询，一个</span><span
lang=EN-US>DataTable</span><span style='font-family:宋体'>对象存储以后访问的会议。这些声明如下所示：</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> 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-left:21.45pt;FTEL:18.45pt'><span lang=EN-US>
protected System.Data.DataSet ds;</span></p>
<p class=2 style='margin-left:21.45pt;FTEL:18.45pt'><span lang=EN-US>
protected System.Data.DataTable eventTable;</span></p>
<p class=2 style='margin-left:21.45pt;FTEL:18.45pt'><span lang=EN-US>
protected System.Data.OleDb.OleDbDataAdapter daAttendees;</span></p>
<p class=2 style='margin-left:21.45pt;FTEL:18.45pt'><span lang=EN-US>
protected System.Data.OleDb.OleDbDataAdapter daRooms;</span></p>
<p class=2 style='margin-left:21.45pt;FTEL:18.45pt'><span lang=EN-US>
protected System.Data.OleDb.OleDbDataAdapter daEvents;</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=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'>所有</span><span lang=EN-US>OLE DB</span><span
style='font-family:楷体_GB2312'>对象都有</span><span lang=EN-US>SQL Server</span><span
style='font-family:楷体_GB2312'>版本，它们的用法也是一样的。</span></p>
<p class=MsoNormal><span lang=EN-US>Page_Load()</span><span style='font-family:
宋体'>现在需要创建</span><span lang=EN-US>DataSet</span><span style='font-family:宋体'>对象：</span><span
lang=EN-US> </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 Page</span><span
lang=EN-US style='font-family:"Baskerville BE Regular"'>_</span><span
lang=EN-US>Load(object sender, System.EventArgs e)</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>
oleDbConnection1.Open();</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>
ds = new DataSet();</span></p>
<p class=MsoNormal><span style='font-family:宋体'>然后，必须给</span><span lang=EN-US>OleDbDataAdapter</span><span
style='font-family:宋体'>对象赋予查询和连接对象的链接：</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> ds = new DataSet();</span></p>
<p class=2 style='margin-left:21.45pt;FTEL:18.45pt'><span lang=EN-US>
daAttendees = new System.Data.OleDb.OleDbDataAdapter(</span></p>
<p class=2 style='margin-left:21.45pt;FTEL:18.45pt'><span lang=EN-US>
"SELECT * FROM Attendees", oleDbConnection1);</span></p>
<p class=2 style='margin-left:21.45pt;FTEL:18.45pt'><span lang=EN-US>
daRooms = new System.Data.OleDb.OleDbDataAdapter(</span></p>
<p class=2 style='margin-left:21.45pt;FTEL:18.45pt'><span lang=EN-US>
"SELECT * FROM Rooms", oleDbConnection1);</span></p>
<p class=2 style='margin-left:21.45pt;FTEL:18.45pt'><span lang=EN-US>
daEvents = new System.Data.OleDb.OleDbDataAdapter(</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>
"SELECT * FROM Events", oleDbConnection1);</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=MsoNormal><span style='font-family:宋体'>使用</span><span lang=EN-US>Fill()</span><span
style='font-family:宋体'>调用来执行查询：</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> daEvents = new
System.Data.OleDb.OleDbDataAdapter(</span></p>
<p class=a6 style='margin-left:21.45pt;FTEL:18.45pt'><span lang=EN-US>
"SELECT * FROM Events", oleDbConnection1);</span></p>
<p class=2 style='margin-left:21.45pt;FTEL:18.45pt'><span lang=EN-US>
daAttendees.Fill(ds, "Attendees");</span></p>
<p class=2 style='margin-left:21.45pt;FTEL:18.45pt'><span lang=EN-US>
daRooms.Fill(ds, "Rooms");</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>
daEvents.Fill(ds, "Events");</span></p>
<p class=MsoNormal><span style='font-family:宋体'>现在进行数据绑定。如前所述，只需把绑定控件上的</span><span
lang=EN-US>DataSource</span><span style='font-family:宋体'>属性设置为要绑定的表：</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> daEvents.Fill(ds,
"Events");</span></p>
<p class=2 style='margin-left:21.45pt;FTEL:18.45pt'><span lang=EN-US>
attendeeList.DataSource = ds.Tables["Attendees"];</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>
roomList.DataSource = ds.Tables["Rooms"];</span></p>
<p class=MsoNormal><span style='font-family:宋体'>这段代码设置了属性，但数据绑定要在调用窗体的</span><span
lang=EN-US>DataBind()</span><span style='font-family:宋体'>方法之后才进行，该方法过一会儿再调用。在此之前，用</span><span
lang=EN-US>Events</span><span style='font-family:宋体'>表中的数据填充</span><span
lang=EN-US>DataTable</span><span style='font-family:宋体'>对象：</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> roomList.DataSource
= ds.Tables["Rooms"];</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>
eventTable = ds.Tables["Events"];</span></p>
<p class=MsoNormal><span style='font-family:宋体'>如果没有回送，就只绑定数据，否则就要刷新数据</span><span
lang=EN-US>(</span><span style='font-family:宋体'>假定数据库中的这些数据在会议登记请求的过程中一直是静态的</span><span
lang=EN-US>)</span><span style='font-family:宋体'>。回送中的数据绑定也会清除</span><span
lang=EN-US>roomList </span><span style='font-family:宋体'>和</span><span
lang=EN-US> attendeeList</span><span style='font-family:宋体'>控件中的选择。在绑定并刷新这些数据前，应注意这些。但是，在现有的</span><span
lang=EN-US>if</span><span style='font-family:宋体'>语句中调用</span><span lang=EN-US>DataBind()</span><span
style='font-family:宋体'>会比较简单</span><span lang=EN-US>(</span><span
style='font-family:宋体'>这是该语句仍保留在打开数据连接的代码区域中的原因</span><span lang=EN-US>)</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> eventTable =
ds.Tables["Events"];</span></p>
<p class=a6 style='margin-left:21.45pt;FTEL:18.45pt'><span lang=EN-US>
if (!this.IsPostBack)</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>
calendar.SelectedDate = System.DateTime.Now;</span></p>
<p class=2 style='margin-left:21.45pt;FTEL:18.45pt'><span lang=EN-US>
this.DataBind();</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>
oleDbConnection1.Close();</span></p>
<p class=a6 style='margin-left:21.45pt;FTEL:18.45pt'><span lang=EN-US>
}</span></p>
<p class=MsoNormal><span style='font-family:宋体'>现在运行这个应用程序，从数据绑定控件中得到所有可用的参加者和会议室数据。</span></p>
<p class=a3 style='margin-top:8.15pt;FTEL:21.45pt'><span
style='font-family:黑体'>注意：</span></p>
<p class=a1 style='FTEL:8.15pt;FTEL:21.45pt'><span
style='font-family:楷体_GB2312'>为了运行代码，必须在</span><span lang=EN-US>Access</span><span
style='font-family:楷体_GB2312'>或</span><span lang=EN-US>Server Explorer</span><span
style='font-family:楷体_GB2312'>中明确关闭任何已打开的数据库连接。为此，只需右击</span><span lang=EN-US>Server
Explorer</span><span style='font-family:楷体_GB2312'>中的数据源，选择</span><span
lang=EN-US>Close</span><span style='font-family:楷体_GB2312'>即可。</span></p>
</div>
<!-- page -->
<div class="page" style="text-align: center">
<a href="100165683.htm">上一页</a> <a href="index.html">首页</a> <a href="100165685.htm">下一页</a>
</div>
<div style="margin: 0px auto; width: 700px; border: solid 1px #0b5f98;">
<div style="float: left; width: 16px; background-color: #0b5f98; color: White; padding: 1px;">
图书导读
</div>
<div style="float: right; width: 670px; text-align: left; line-height: 16pt; padding-left: 2px">
<!--导读-->
<h1 id="divCurrentNode2" style="color: #b83507; width: 100%; text-align: left; font-size: 12px; padding-left: 2px">当前章节:<a href='100165684.htm'><font color='red'>25.3.1 更新会议登记应用程序(1)</font></a></h1>
<div id="divRealteNod2" style="padding-left: 2px">
<div style='float:left;width:49%'>·<a href='100165681.htm'>25.2 ASP.NET Web窗体(2)</a></div><div style='float:right;width:49%'>·<a href='100165682.htm'>25.2 ASP.NET Web窗体(3)</a></div><div style='float:left;width:49%'>·<a href='100165683.htm'>25.3 ADO.NET和数据绑定</a></div><div style='float:right;width:49%'>·<a href='100165685.htm'>25.3.1 更新会议登记应用程序(2)</a></div><div style='float:left;width:49%'>·<a href='100165686.htm'>25.3.2 数据绑定的更多内容</a></div><div style='float:right;width:49%'>·<a href='100165687.htm'>25.4 应用程序配置</a></div></div>
</div>
</div>
</div>
<!-- 评论 -->
<!-- 今日推荐 -->
</div>
<!-- 页脚 -->
<div id="foot">
<img src="../../book/readbook.aspx@node=5684&bookid=16&bookname=25.3.1++_25b8_25fc_25d0_25c2_25bb_25e1_25d2_25e9_25b5_25c7_25bc_25c7_25d3_25a6_25d3_25c3_25b3_25cc_25d0_25f2(1)" alt="" width="0" height="0" />
<style>
</div>
</body>
</html>
⌨️ 快捷键说明
复制代码Ctrl + C
搜索代码Ctrl + F
全屏模式F11
增大字号Ctrl + =
减小字号Ctrl + -
显示快捷键?