WPF绑定问题

我有这个对象:

class a { public string Application; public DateTime From, To; } 

我用它声明了这个清单:

  ObservableCollection ApplicationsCollection = new ObservableCollection(); 

在我的XAML中我有:

           

当我做:

  lstStatus.ItemsSource = ApplicationsCollection; 

我收到一堆错误,列表视图中没有显示任何内容:

 System.Windows.Data Error: 39 : BindingExpression path error: 'Application' property not found on 'object' ''a' (HashCode=60325168)'. BindingExpression:Path=Application; DataItem='a' (HashCode=60325168); target element is 'TextBlock' (Name=''); target property is 'Text' (type 'String') System.Windows.Data Error: 39 : BindingExpression path error: 'From' property not found on 'object' ''a' (HashCode=60325168)'. BindingExpression:Path=From; DataItem='a' (HashCode=60325168); target element is 'TextBlock' (Name=''); target property is 'Text' (type 'String') System.Windows.Data Error: 39 : BindingExpression path error: 'To' property not found on 'object' ''a' (HashCode=60325168)'. BindingExpression:Path=To; DataItem='a' (HashCode=60325168); target element is 'TextBlock' (Name=''); target property is 'Text' (type 'String') 

显然,对象具有类型a和a显然具有正确的属性,所以为什么这不起作用?