C# 谈谈Interface和通过Interface传递web页面数据

接口：描述可属于任何类或结构的一组相关功能，通过interface关键字来声明；
接口只包含方法、委托或事件和属性的签名（接口包含的成员）、不能包含字段（因为字段是包含数据的）。方法的实现是“继承”接口的类中完成的；
接口可以包含的成员的访问修饰符只能且默认为public；
一个接口可以从一个或多个基接口继承；
接口类似于抽象基类：继承接口的任何非抽象类型都必须实现接口的所有成员；
当基类型列表包含基类和接口时，基类必须是列表中的第一项；
实现接口的类可以显式实现该接口的成员，显示实现的成员不能通过类实例访问，而只能通过接口实例访问；
类和结构可以按照类继承基类或结构的类似方式继承接口；但注意：
类或结构可继承多个接口；
类或结构继承接口时，仅继承方法名称和签名，因为接口本身不包含实现；
接口和接口成员是抽象的（但不用写出abstract关键字）；接口不提供默认实现；

接口是一种规划（为你定义出一系列的规则和任务，但不去实现它）;

先看一个实例:

interface IPoint
{
// Property signatures:
int x
{
get;
set;
}

int y
{
get;
set;
}
}

class Point : IPoint
{
// Fields:
private int _x;
private int _y;

// Constructor:
public Point(int x, int y)
{
_x = x;
_y = y;
}

// Property implementation:
public int x
{
get
{
return _x;
}

set
{
_x = value;
}
}

public int y
{
get
{
return _y;
}
set
{
_y = value;
}
}
}

class MainClass
{
static void PrintPoint(IPoint p)
{
Console.WriteLine("x={0}, y={1}", p.x, p.y);
}

static void Main()
{
Point p = new Point(2, 3);
Console.Write("My Point: ");
PrintPoint(p);
}
}
// Output: My Point: x=2, y=3

上面是一个简单的接口实现,如果在一个Web网页上的.CS文件中继承一个接口,如下:

先定义接口:

public interface Iuser
  {
      string UserName { set; get; }
      string Role { set; get; }
      string Age { set; get; }
      string Sex { set; get; }
      bool Userlogin(string Name,string PassWord);
 
  }

新建一个页面Login.aspx,代码如下;

<body>
    <form id="form1" runat="server">
    <div>
     
        <table class="style1">
            <tr>
                <td class="style2">
                    <asp:Label ID="lblUsername" runat="server" Text="Username"></asp:Label>
                </td>
                <td>
                    <asp:TextBox ID="txtUserName" runat="server"></asp:TextBox>
                </td>
            </tr>
            <tr>
                <td class="style2">
                    <asp:Label ID="lblPassWord" runat="server" Text="PassWord"></asp:Label>
                </td>
                <td>
                    <asp:TextBox ID="txtPassWord" runat="server"></asp:TextBox>
                </td>
            </tr>
            <tr>
                <td class="style2">
                     </td>
                <td>
                    <asp:Button ID="btnSubmit" runat="server" onclick="btnSubmit_Click"
                        Text="Submit" />
                </td>
            </tr>
            <tr>
                <td class="style2">
                     </td>
                <td>
                    <asp:Label ID="lblMessage" runat="server"></asp:Label>
                </td>
            </tr>
        </table>
     
    </div>
    </form>
</body>

public partial class Login : Iuser
{
    protected void Page_Load(object sender, EventArgs e)
    {
 
    }
    private string _Age;
    private string _Role;
    private string _Sex;
    private string _UserName;
 
    #region Iuser Members
 
    public string Age
    {
        get
        {
            return _Age;
        }
        set
        {
            _Age = value;
        }
    }
 
    public string Role
    {
        get
        {
            return _Role;
        }
        set
        {
            _Role = value;
        }
    }
 
    public string Sex
    {
        get
        {
            return _Sex;
        }
        set
        {
            _Sex = value;
        }
    }
 
    public string UserName
    {
        get
        {
            return _UserName;
        }
        set
        {
            _UserName = value;
        }
    }
 
 
    public bool Userlogin(string Name, string PassWord)
    {
        return true;
    }
    #endregion
 
    protected void btnSubmit_Click(object sender, EventArgs e)
    {
        if (Userlogin(txtUserName.Text, txtPassWord.Text))
        {
            lblMessage.Text = "login Successful!";
            SetUserInfo(txtUserName.Text);
        }
        else
        {
            lblMessage.Text = "Login  fail!";
        }
    }
    protected void SetUserInfo(string Name)
    {
        Age = "25";
        Role = "Visit";
        Sex = "Man";
        UserName = "spring yang";
    }
 
}

然后新建一个UsingUser.cs类;

代码如下:

public class UsingUser : WebPart, Iuser
{
    private string _Age;
    private string _Role;
    private string _Sex;
    private string _UserName;
 
    #region Iuser Members
 
    public string Age
    {
        get
        {
            return _Age;
        }
        set
        {
            _Age = value;
        }
    }
 
    public string Role
    {
        get
        {
            return _Role;
        }
        set
        {
            _Role = value;
        }
    }
 
    public string Sex
    {
        get
        {
            return _Sex;
        }
        set
        {
            _Sex = value;
        }
    }
 
    public string UserName
    {
        get
        {
            return _UserName;
        }
        set
        {
            _UserName = value;
        }
    }
 
 
    public bool Userlogin(string Name, string PassWord)
    {
        return true;
    }
    #endregion
    private void AddControlToWebPart()
    {
        Type controlType = Type.GetType("ASP.web_Login_aspx,webinterface, Version=1.0.0.0, Culture=neutral, PublicKeyToken=9f4da00116c38ec5");
        System.Web.UI.UserControl userControl = (System.Web.UI.UserControl)this.Page.LoadControl(controlType, null);
        Iuser iuserProperty = userControl as Iuser;
 
        Age = iuserProperty.Age;
        Role = iuserProperty.Role;
        Sex = iuserProperty.Sex;
        UserName = iuserProperty.UserName;
        
        this.Controls.Add(userControl);
    }
}