我有一个MyViewModel,其中包含标量属性和集合属性。
public class MyViewModel :
System.ComponentModel.INotifyPropertyChanged,
System.ComponentModel.IDataErrorInfo
{
public MyViewModel()
{
List<SelectableObject> list = new List<SelectableObject>();
foreach (var weekDay in System.Threading.Thread.CurrentThread.CurrentCulture.DateTimeFormat.DayNames)
{
list.Add(new SelectableObject() { Name = weekDay, IsSelected = false });
}
WeekDays = list;
}
public string Catalog { get; set; }
public DateTime CreationTime { get; set; }
public DateTime ModificationTime { get; set; }
public IEnumerable<SelectableObject> WeekDays { get; private set; }
public ICommand SaveCommand { get; private set; }
public string Error
{
get { return string.Empty; }
}
public string this[string columnName]
{
get
{
var errorResult = string.Empty;
switch (columnName)
{
case "CreationTime":
// Validation logic
break;
case "ModificationTime":
// Validation logic
break;
default:
break;
}
return errorResult;
}
}
}
可选对象类:
public class SelectableObject : System.ComponentModel.INotifyPropertyChanged
{
public string Name { get; set; }
public bool IsSelected { get; set; }
}
我想通过SaveCommand操作<Button />的IsEnabled属性,并且我希望它启用,前提是表单上没有错误。但我不知道如何验证这一点:必须至少选择一个 WeekDay。
是的,我可以监听WeekDays集合中每个对象的PropertyChanged事件,但在这种情况下,验证逻辑将与IDataErrorInfo接口分离。
这个问题有什么解决办法吗?如何将集合的验证逻辑放入IDataErrorInfo接口?