Unity3d-C#之where

where简单的说就是做范型约束，更多内容参见官方文档:http://msdn.microsoft.com/zh-cn/library/bb384067.aspx

namespace TestCSharp
{
    class BaseView
    {
        public int ViewId;
        public string ViewName;

        public string GetInfo()
        {
            return string.Format("viewid:{0},viewName:{1}",this.ViewId,this.ViewName);
        }
    }
}

namespace TestCSharp
{
    class BattleView : BaseView
    {
        public string CityName;
        public int Hp;

        public BattleView()
        {
            this.ViewId = 1;
            this.ViewName = "BattleView";
        }
    }
}

namespace TestCSharp
{
    class LoginView : BaseView
    {
        public string UserName;
        public string Password;

        public LoginView()
        {
            this.ViewId = 0;
            this.ViewName = "LoginView";
        }
    }
}

using System;

namespace TestCSharp
{
    class ViewFactory<T> where T : BaseView, new()
    {
        private readonly T mView = new T();

        public void Print()
        {
            Console.WriteLine(mView.GetInfo());
        }
    }
}

using System;
using System.Collections;
using System.Collections.Generic;

namespace TestCSharp
{
 
    class MainClass
    {
        public static void Main(string[] args)
        {
            ViewFactory<LoginView> loginView = new ViewFactory<LoginView>();
            loginView.Print();

            ViewFactory<BattleView> battleView = new ViewFactory<BattleView>();
            battleView.Print();

            //error
            //ViewFactory<Object> createCharView = new ViewFactory<Object>();
        }

      
    }
   
}

上面是约束构造函数，使用 new 运算符创建类型参数的实例。下面我们改造为函数

using System;

namespace TestCSharp
{
    class ViewFactory
    {


        public static void RegView<T>(int viewId, string viewName) where T : BaseView, new()
        {
            
            T mView = new T {ViewId = viewId, ViewName = viewName};
            Console.WriteLine(mView.GetInfo());
        }

    }
}

using System;
using System.Collections;
using System.Collections.Generic;

namespace TestCSharp
{
 
    class MainClass
    {
        public static void Main(string[] args)
        {
            ViewFactory.RegView<LoginView>(100,"LoginView");
            ViewFactory.RegView<BattleView>(200, "BattleView");
        }

      
    }
   
}

同样也是创建对象的约束。