WPF MVVM 服务层

WPF MVVM 服务层：简化开发，提高可维护性

csharp
// 服务层接口
public interface IDataService
{
    List GetItems();
    void AddItem(string item);
}
// 服务层实现
public class DataService : IDataService
{
    private List _items;
    public DataService()
    {
        _items = new List();
    }
    public List GetItems()
    {
        return _items;
    }
    public void AddItem(string item)
    {
        _items.Add(item);
    }
}