What is ASP.NET
ASP.NET is a unified Web development model that includes the services necessary for you to build enterprise-class Web applications with a minimum of coding. ASP.NET is part of the .NET Framework, and when coding ASP.NET applications you have access to classes in the .NET Framework. You can code your applications in any language compatible with the common language runtime (CLR), including Microsoft Visual Basic, C#, JScript .NET, and J#. These languages enable you to develop ASP.NET applications that benefit from the common language runtime, type safety, inheritance, and so on.
ASP.NET includes:
A page and controls framework
The ASP.NET compiler
Security infrastructure
State-management facilities
Application configuration
Health monitoring and performance features
Debugging support
An XML Web services framework
Extensible hosting environment and application life cycle management
An extensible designer environment
本文来自CSDN博客，转载请标明出处：http://blog.csdn.net/chimomo/archive/2009/09/04/4519542.aspx
用户控件是ASP.NET中很重要的一部分，使用它可以提高程序代码的重用性，即一个用户控件在网页、用户控件或控件的内部都可以再次使用。本实例介绍用户登录的用户控件也可以在网站的任何地方再次使用。
技术要点
本实例介绍如何在ASP.NET中创建用户控件、如何使用用户控件，以及如何在用户控件中定义公开属性的实现方法。
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假定有一个Product表，字段有（Id,Name,Quantity,...）将Quantity列用textbox格式来显示：
首先在Gridview中，Quantity列以TemplateField显示，其他的列属性设为只读，把显示格式设为TextBox
<asp:TemplateField HeaderText="Quantity">
<ItemTemplate>
&nbs ......
