EVAL检查的DBNull不工作 [英] Eval check for DBNull doesnt work

问题描述

<%# Eval("Description") == DBNull.Value ? "empty" : "notempty"%>

总是显示出一个'NotEmpty'甚至有在DB那场空（VARCHAR（类型），空）
...
尝试也检查空字符串：

is showing always 'notempty' even there is null in that field in DB (type of varchar(), null) ... Tried also checking for empty string:

<%# Eval("Description") == "" ? "empty" : "notempty"%>

和它总是显示notempty ...什么是错在这里？

and it always displays notempty... what's wrong here??

推荐答案

有 DBNull.Value 和空。这是可能的领域正在恢复空。

There is a difference between DBNull.Value and null. It is possible the field is returning null.

尝试

<%# Eval("Description") == null ? "empty" : "notempty"%>

此外，如果字段值类型应该是字符串，你可以沿着线做一些事情。

Also if the field value type is supposed to be string you could do something along the lines of..

<%# (Eval("Description") as string) ?? "empty" %>

这篇关于EVAL检查的DBNull不工作的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持IT屋！