100165633.htm
来自「C#高级编程(第三版),顶死你们。。 。up」· HTM 代码 · 共 321 行 · 第 1/4 页
HTM
321 行
<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">
<html xmlns="http://www.w3.org/1999/xhtml">
<head><title>
22.3.6 其他常见的要求
</title></head>
<body>
<div class="area">
<div class="col1">
<div class="lineBlue">
</div>
<!-- title -->
<div class="arcTitle">
<h1>
<a href="../16">
C#高级编程（第3版）
</a>
</h1>
<div style="text-align: center; font-size: 15px">
<a href="100165633.htm">
22.3.6 其他常见的要求
</a>
</div>
<div style="text-align: center; font-size: 15px">
<a class="url" href="../../default.htm">http://book.csdn.net/</a>
2006-10-13 14:41:00
</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="divCurrentNode" style="color: #b83507; width: 100%; text-align: left; font-size: 12px; padding-left: 2px">当前章节:<a href='100165633.htm'><font color='red'>22.3.6 其他常见的要求</font></a></h1>
<div id="divRelateNode" style="padding-left: 2px">
<div style='float:left;width:49%'>·<a href='100165630.htm'>22.3.3 生成DataSet</a></div><div style='float:right;width:49%'>·<a href='100165631.htm'>22.3.4 更新数据源</a></div><div style='float:left;width:49%'>·<a href='100165632.htm'>22.3.5 构建模式</a></div><div style='float:right;width:49%'>·<a href='100165634.htm'>22.4 小结</a></div><div style='float:left;width:49%'>·<a href='100165635.htm'>23.1 .NET支持的XML标准</a></div><div style='float:right;width:49%'>·<a href='100165636.htm'>23.2 System.Xml命名空间</a></div></div>
</div>
</div>
</div>
<!-- main -->
<div id="main">
<div id="text">
<div id="csdn_zhaig_ad_yahoo_2"></div>
<link href="css.css" rel="stylesheet" type="text/css" /><h3 style="MARGIN-TOP: 8.15pt; MARGIN-LEFT: 0cm; MARGIN-RIGHT: 0cm; FTEL: 8.15pt"><a ftel="_Toc507815191"><span lang="EN-US">22.3.6 </span></a><span style="FONT-FAMILY: 黑体">其他常见的要求</span></h3>
<p class="MsoNormal"><span style="FONT-FAMILY: 宋体">在显示数据时，一个常见的要求是为给定的行提供一个弹出式菜单。这有很多方式，本例介绍的一种方式可以简化需要的代码，特别适合于下述情况：显示环境是在</span><span lang="EN-US">DataGrid</span><span style="FONT-FAMILY: 宋体">中，在该环境中显示了带有一些关系的</span><span lang="EN-US">DataSet</span><span style="FONT-FAMILY: 宋体">。问题是弹出的菜单与所选的行有关，该行可以来自于该</span><span lang="EN-US">DataSet</span><span style="FONT-FAMILY: 宋体">中的任意一个源数据表。</span></p>
<p class="MsoNormal"><span style="FONT-FAMILY: 宋体">弹出菜单的功能似乎很一般，但它可以利用一个支持菜单的基类</span><span lang="EN-US">(ContextDataRow)</span><span style="FONT-FAMILY: 宋体">，每个数据行类都支持从这个基类派生来的一个弹出菜单。</span></p>
<p class="MsoNormal"><span style="FONT-FAMILY: 宋体">用户右击</span><span lang="EN-US">DataGrid</span><span style="FONT-FAMILY: 宋体">中一行的任何一部分，都可以查看该行，确定它是否派生于</span><span lang="EN-US">ContextDataRow</span><span style="FONT-FAMILY: 宋体">，如果是，就可以调用</span><span lang="EN-US">PopupMenu()</span><span style="FONT-FAMILY: 宋体">函数。这可以使用一个接口来实现，但在本例中，使用基类会比较简单。</span></p>
<p class="MsoNormal"><span style="FONT-FAMILY: 宋体">本例说明了如何生成</span><span lang="EN-US">DataRow </span><span style="FONT-FAMILY: 宋体">和</span><span lang="EN-US"> DataTable</span><span style="FONT-FAMILY: 宋体">类，以便对数据进行类型安全的访问，这与前<span style="LETTER-SPACING: 0.1pt">面</span></span><span lang="EN-US" style="LETTER-SPACING: 0.1pt">XSD</span><span style="FONT-FAMILY: 宋体; LETTER-SPACING: 0.1pt">示例采用的方式相同，但这次代码是手工编写的。它还说明了定制属性和反射的一个用法</span><span style="FONT-FAMILY: 宋体">。</span></p>
<p class="MsoNormal"><span style="FONT-FAMILY: 宋体">图</span><span lang="EN-US">22-28</span><span style="FONT-FAMILY: 宋体">显示了这个示例的类层次结构。</span></p>
<p align="center"><span lang="EN-US"><img height="133" src="22/image028.gif" width="382" alt="" /></span></p>
<p style="FTEL: 8.15pt" align="center"><span style="FONT-FAMILY: 宋体">图</span><span lang="EN-US"> 22-28</span></p>
<p class="MsoNormal"><span style="FONT-FAMILY: 宋体">这个示例的代码如下：</span></p>
<p class="2" style="MARGIN-TOP: 8.15pt; MARGIN-LEFT: 21.45pt; MARGIN-RIGHT: 0cm; FTEL: 18.45pt"><span lang="EN-US">using System;</span></p>
<p class="2" style="MARGIN-LEFT: 21.45pt; FTEL: 18.45pt"><span lang="EN-US">using System.Windows.Forms;</span></p>
<p class="2" style="MARGIN-LEFT: 21.45pt; FTEL: 18.45pt"><span lang="EN-US">using System.Data;</span></p>
<p class="2" style="MARGIN-LEFT: 21.45pt; FTEL: 18.45pt"><span lang="EN-US">using System.Data.SqlClient;</span></p>
<p class="2" style="MARGIN-LEFT: 21.45pt; FTEL: 18.45pt"><span lang="EN-US">using System.Reflection;</span></p>
<p class="2" 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">public class ContextDataRow : DataRow</span></p>
<p class="2" 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"> public ContextDataRow(DataRowBuilder builder) : base(builder)</span></p>
<p class="2" 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"> }</span></p>
<p class="2" style="MARGIN-LEFT: 21.45pt; FTEL: 18.45pt"><span lang="EN-US"> public void PopupMenu(System.Windows.Forms.Control parent, int x, int y)</span></p>
<p class="2" 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"> </span></p>
<p class="2" style="MARGIN-LEFT: 21.45pt; FTEL: 18.45pt"><span lang="EN-US"> // Use reflection to get the list of popup menu commands</span></p>
<p class="2" style="MARGIN-LEFT: 21.45pt; FTEL: 18.45pt"><span lang="EN-US"> MemberInfo[] members = this.GetType().FindMembers (MemberTypes.Method,</span></p>
<p class="2" style="MARGIN-LEFT: 21.45pt; FTEL: 18.45pt"><span lang="EN-US"> BindingFlags.Public | BindingFlags.Instance ,</span></p>
<p class="2" style="MARGIN-LEFT: 21.45pt; FTEL: 18.45pt"><span lang="EN-US"> new System.Reflection.MemberFilter(Filter),</span></p>
<p class="2" style="MARGIN-LEFT: 21.45pt; FTEL: 18.45pt"><span lang="EN-US"> null);</span></p>
<p class="2" style="MARGIN-LEFT: 21.45pt; FTEL: 18.45pt"><span lang="EN-US"> if (members.Length > 0)</span></p>
<p class="2" 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"> </span></p>
<p class="2" style="MARGIN-LEFT: 21.45pt; FTEL: 18.45pt"><span lang="EN-US"> // Create a context menu</span></p>
⌨️ 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?