在Rdlc报表中检查Null值 [英] check Null value in Rdlc Report

问题描述

我想检查文本框字段中的Null值，如果它为Null，则打印一些内容.我尝试了Is Nothing但仍显示#ERROR.

= IIF(Fields！NonTechHours.Value is Nothing，"Null"，IIF(Right(Fields！NonTechHours.Value，InStr(Fields！NonTechHours.Value，."))> 0，Fields！NonTechHours.Value，Left( Fields！NonTechHours.Value，InStr(Fields！NonTechHours.Value，.")-1))))

Hi,
I want to check Null value in textbox field,if it ''s Null,then print something.I tried Is Nothing but still getting the #ERROR display.

=IIF(Fields!NonTechHours.Value is Nothing,"Null",IIF(Right(Fields!NonTechHours.Value,InStr(Fields!NonTechHours.Value,"."))>0,Fields!NonTechHours.Value,Left(Fields!NonTechHours.Value,InStr(Fields!NonTechHours.Value,".")-1)))

推荐答案

如果您使用的是.Net 2.0或更高版本，您实际上可以使用null合并运算符-??.

这将自动将null转换为".
您的代码将类似于Fields!NonTechHours.Value?? "".

If you are using .Net 2.0 or above, you can actually use the null coalesce operator - ??.

This will convert null into "" automatically.
Your code will be something like Fields!NonTechHours.Value?? "".

textbox类的text属性是一个字符串.它甚至不会接受System.DBNull.Value作为值.如果将其设置为与其他对象相等，则将其转换为字符串.

基于此，TextBox1.Text = ""和其他任何东西一样可行.

The text property of the textbox class is a string. It wont even accept System.DBNull.Value as a value. If you set it equal to some other object, it will be cast as string.

Based on this,TextBox1.Text = "" is just as viable as anything else.

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