可空对象必须具有值吗? [英] Nullable object must have a value?
本文介绍了可空对象必须具有值吗?的处理方法,对大家解决问题具有一定的参考价值,需要的朋友们下面随着小编来一起学习吧!
问题描述
在线:bool travel = fill.travel.Value;
我收到以下错误:
On the line: bool travel = fill.travel.Value;
I am getting the following error:
可空对象必须具有值
Nullable object must have a value
我不确定为什么.我要做的就是获取旅行数据库中当前为假的值.任何帮助,将不胜感激.
and i am not sure why. All I want to do is get the value in the database of travel which is currently false. Any help would be appreciated.
using (var db = new DataClasses1DataContext())
{
var fill = (from f in db.expenseHdrs
where f.rptNo == getPkRowReport()
select f).FirstOrDefault();
txtReportDesc.Text = fill.description;
txtPeriod.Text = fill.period;
txtPurpose.Text = fill.purpose;
bool travel = fill.travel.Value;
chkTravel.Checked = travel
}
推荐答案
您随时可以切换到
fill.travel.GetValueOrDefault()
提供默认值(false)或数据库中布尔列的值.或者,您可以指定带有重载的默认值.无论哪种方式,当前可为null的值都没有值,这就是为什么您会得到该异常的原因.
To provide the default (false), or the value of the boolean column from the database. Or you can specify the default with an overload. Either way, the nullable currently doesnt have a value, which is why you get that exception.
这篇关于可空对象必须具有值吗?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!
查看全文