如何创建泛型类的属性？

Question

我有这个代码:

public class SelectionList<T> : ObservableCollection<SelectionItem<T>> where T : IComparable<T>
{
  // Code 
}

public class SelectionItem<T> : INotifyPropertyChanged
{
// Code
}

我需要创建一个类型SelectionList如下的属性:

public SelectionList<string> Sports { get; set; }

但是当我用DataRowView替换字符串时,如

 public SelectionList<DataRowView> Sports { get; set; }`

我收到了一个错误.为什么这不起作用？

Answer 1

你的问题是string实现IComparable<string>而DataRowView不是.

SelectionList<T>有一个T必须实现的约束IComparable<T>,因此错误.

public class SelectionList<T> : ObservableCollection<SelectionItem<T>> where T : IComparable<T>
{
  // Code 
}

一种解决方案是将DataRowView子类化并实现IComparable:

public class MyDataRowView : DataRowView, IComparable<DataRowView>{
  int CompareTo(DataRowView other) {
    //quick and dirty comparison, assume that GetHashCode is properly implemented
    return this.GetHashCode() - (other ? other.GetHashCode() : 0);
  }
}

那SelectionList<MyDataRowView>应该编译好.