如果你要在一个ASP.NET页面之上执行大数据的读取和显示，那么你就很可能接收到如下错误信息：
Server Error in '/' Application.
Request timed out.
Description: An unhandled exception occurred during the execution of the current web request. Please review the stack trace for more information about the error and where it originated in the code.
Exception Details: System.Web.HttpException: Request timed out.
Source Error: An unhandled exception was generated during the execution of the current web request. Information regarding the origin and location of the exception can be identified using the exception stack trace below.
Stack Trace: [HttpException (0x80004005): Request timed out.]
解决方法：
修改Web.Config或者Machine.Config文件中的配置即可！
<configuration>
<system.web>
<httpRuntime=20 executionTimeout="36000" />
</system.web>
</configuration>
好像最大值就是1小时左右，如果太长了，你就要想办法优化你的叶面程序了。