在WPF验证两个属性 [英] Validating two properties in WPF
本文介绍了在WPF验证两个属性的处理方法,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
我有这种属性的类:
public DateTime Start { get; set; }
public DateTime Finish { get; set; }
和这样的视图模型:
<StackPanel>
<DatePicker SelectedDate="{Binding Start}" />
<DatePicker SelectedDate="{Binding Finish}" />
</StackPanel>
我想启用验证。所以,当开始>完成,必须有错误。什么是提供这样的验证最简单的方法?
I want to enable validation. So, when Start > Finish there must be error. What is the simplest way to provide such validation?
推荐答案
好吧,我已经找到答案我自己)我伸出我的TIMERANGE类来实现这样的IDataErrorInfo的接口:
Well, I've found answer myself) I extended my TimeRange class to implement IDataErrorInfo interface like this:
public class TimeRange : IDataErrorInfo
{
public DateTime Start { get; set; }
public DateTime Finish { get; set; }
#region IDataErrorInfo Members
public string Error
{
get { throw new NotImplementedException(); }
}
private bool _IsValid()
{
return Finish > Start;
}
public string this[string columnName]
{
get
{
string result = null;
if (columnName == "Start" && !_IsValid())
result = "Start must occure before Finish!";
else if (columnName == "Finish" && !_IsValid())
result = "Finish must occure after Start!";
return result;
}
}
#endregion
}
然后改变我的XAML代码:
And then change my xaml code to:
<DatePicker SelectedDate="{Binding Start, UpdateSourceTrigger=LostFocus,
ValidatesOnDataErrors=true, NotifyOnValidationError=true}" />
<DatePicker SelectedDate="{Binding Finish, UpdateSourceTrigger=LostFocus,
ValidatesOnDataErrors=true, NotifyOnValidationError=true}" />
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