问题描述
上线: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:
可空对象必须有值
我不知道为什么.我想要做的就是获取当前为假的旅行数据库中的值.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
您可以随时切换到
fill.travel.GetValueOrDefault()
提供默认值 (false) 或数据库中布尔列的值.或者您可以使用重载指定默认值.无论哪种方式,可空对象当前都没有值,这就是您得到该异常的原因.
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.