材料清单:Mobile(手机),MiniCharger(迷你充电器),IUsb(USB接口),
设计思路:
1.声明IUsb约定对象之间的交互方式,其中包含一个事件;
2.Mobile实现IUsb接口,这是关键点,是调用者实现接口,需求通过事件委托给充电设备自行处理;
3.Mobile反射充电设备,通过构造函数注入IUsb;
代码清单:
1 public interface IUsb { 2 decimal Voltage { get; set; } 3 event System.EventHandler Connecting; 4 }
1 <%@ Page Language="C#" AutoEventWireup="true" CodeFile="Mobile.aspx.cs" Inherits="Mobile" %> 2 3 <!DOCTYPE html> 4 5 <html xmlns="http://www.w3.org/1999/xhtml"> 6 <head runat="server"> 7 <meta http-equiv="Content-Type" content="text/html; charset=utf-8"/> 8 <title></title> 9 </head> 10 <body> 11 <form id="form1" runat="server"> 12 <div> 13 <label>电压:</label><asp:Label ID="lblVoltage" runat="server" Text="0" ></asp:Label> 14 <asp:Label ID="lblMessage" runat="server" Text="没电了" ></asp:Label> 15 <asp:DropDownList ID="drpSelect" runat="server"> 16 <asp:ListItem Text="迷你充电器" Value="MiniCharger"></asp:ListItem> 17 </asp:DropDownList> 18 <asp:Button ID="btnConnect" runat="server" Text="连接充电设备" OnClick="btnConnect_Click" /> 19 </div> 20 </form> 21 </body> 22 </html>
1 using System; 2 public partial class Mobile : System.Web.UI.Page, IUsb { 3 public decimal Voltage { get; set; } 4 public event EventHandler Connecting; 5 protected const decimal Increment = 0.5m; 6 protected const decimal Max = 5.0m; 7 8 protected object LoadCharger(string pType) { 9 string _fileName = "Z:\" + pType + ".dll"; 10 object[] _args = new object[] { this }; 11 return System.Activator.CreateInstanceFrom( 12 _fileName, pType, true, 0, null, _args, null, null); 13 } 14 15 protected void btnConnect_Click(object sender, EventArgs e) { 16 this.LoadCharger(this.drpSelect.SelectedItem.Value); 17 this.ShowMessage(); 18 } 19 20 protected void ShowMessage() { 21 if (this.Connecting == null) this.lblMessage.Text = "设备无响应"; 22 else { 23 this.Connecting(null, EventArgs.Empty); 24 this.lblVoltage.Text = this.Voltage.ToString(); 25 this.lblMessage.Text = (this.Voltage==0)?"设备无充电功能" 26 : (this.Voltage == Max) ? "瞬间充满" 27 :"充电中"; 28 } 29 } 30 31 }
1 using System; 2 [Serializable] 3 public class MiniCharger { 4 protected IUsb Usb { get; set; } 5 protected const decimal Voltage = 5.0m; 6 public MiniCharger(IUsb pElement) { 7 this.Usb = pElement; 8 this.Usb.Connecting += Element_Connecting; 9 } 10 11 void Element_Connecting(object sender, EventArgs e) { 12 this.Usb.Voltage = Voltage; 13 } 14 }
我只是写个骨架,有兴趣的朋友可以多实现几个不同类型的Usb设备,
并且可以尝试扩展Usb接口的功能,比如说为手机增加拷贝数据的功能,
看看连接笔记本电脑和充电器的不同效果