构造函数带有this和base的作用

        #region "Constructor"
        /// <summary>
        /// 构造函数
        /// </summary>
        public NavigationUrl()
            : this(string.Empty, string.Empty, string.Empty, BtnType.Href, false)
        {

        }

        /// <summary>
        /// 重载构造函数
        /// </summary>
        /// <param name="bText">按钮的文字</param>
        /// <param name="bUrl">按钮的javascript/vbscript的Onclick字符</param>
        /// <param name="bHint">按钮提示信息</param>
        /// <param name="bType">按钮链接类型</param>
        /// <param name="bDefault">是否默认选中当前按钮</param>
        public NavigationUrl(string bText, string bUrl, string bHint, BtnType bType, bool bDefault)
        {
            _btnText = bText;
            _btnUrl = bUrl;
            _btnHint = bHint;
            _btnType = bType;
            _btnDefaultSelect = bDefault;
        }
        #endregion

 base是调用基类的构造方法，而this是调用类自身的构造方法。

上面的例子中，当调用第一个构造函数时，执行完继续执行第二构造函数。

 

构造函数中base与this的区别：

namespace ConsoleApplication1
{
    class A
    {
        private int x;
        
        public A()
        {
            Console.WriteLine("this is class A no arg here, value:{0}", x);  
        }

        public A(int i)
        {
            x = i;
            Console.WriteLine("this is class A one arg here, value:{0}", x);
        }
    }

    class B : A
    {
        private int y;

        public B()
        {
            y = 1;
            Console.WriteLine("this is class B no arg here, value:{0}", y);
        }

        public B(int i)
        {
            y = i;
            Console.WriteLine("this is class B one arg here, value :{0}", y);
        }

        public B(int i, int b)
            : base(i)
        {
            y = b;
            Console.WriteLine("this is class B two arg here, value:{0}", y);
        }
    }

    class Program
    {
        static void Main(string[] args)
        {
            B s = new B(5, 8);
            Console.ReadLine();
        }
    }
}

上面例子输出的结果是：

this is class A one arg here, value:5

this is class B two arg here, value:8

如果把base换成this, 结果是：

this is class A no arg here, value:0

this is class B one arg here, value:5

this is class B two arg here, value:8

可见：base是调用基类的构造方法，而this是调用类自身的构造方法。如果用base的时候调用的不是基类无参构造函数，那么在初始化的时候基类中的无参构造函数也会自动初始化。