模型
using System;
using System.Collections;
using System.Data;
using System.Data.SqlClient;
public class DatabaseGateway
{
public static DataSet GetRecordings()
{
String selectCmd = "select * from Recording";
SqlConnection myConnection =
new SqlConnection(
"server=(local);database=recordings;Trusted_Connection=yes");
SqlDataAdapter myCommand = new SqlDataAdapter(selectCmd, myConnection);
DataSet ds = new DataSet();
myCommand.Fill(ds, "Recording");
return ds;
}
public static DataSet GetTracks(string recordingId)
{
String selectCmd =
String.Format(
"select * from Track where recordingId = {0} order by id",
recordingId);
SqlConnection myConnection =
new SqlConnection(
"server=(local);database=recordings;Trusted_Connection=yes");
SqlDataAdapter myCommand = new SqlDataAdapter(selectCmd, myConnection);
DataSet ds = new DataSet();
myCommand.Fill(ds, "Track");
return ds;
}
控制
using System;
using System.Data;
using System.Collections;
using System.Web.UI.WebControls;
public class Solution : System.Web.UI.Page
{
protected System.Web.UI.WebControls.Button submit;
protected System.Web.UI.WebControls.DataGrid MyDataGrid;
protected System.Web.UI.WebControls.DropDownList recordingSelect;
private void Page_Load(object sender, System.EventArgs e)
{
if(!IsPostBack)
{
DataSet ds = DatabaseGateway.GetRecordings();
recordingSelect.DataSource = ds;
recordingSelect.DataTextField = "title";
recordingSelect.DataValueField = "id";
recordingSelect.DataBind();
}
}
void SubmitBtn_Click(Object sender, EventArgs e)
{
DataSet ds =
DatabaseGateway.GetTracks(
(string)recordingSelect.SelectedItem.Value);
MyDataGrid.DataSource = ds;
MyDataGrid.DataBind();
}
#region Web Form Designer generated code
override protected void OnInit(EventArgs e)
{
//
// CODEGEN: 此调用是 ASP.NET Web 窗体设计器所必需的。
//
InitializeComponent();
base.OnInit(e);
}
/// <summary>
/// 设计器支持所必需的方法 - 不要使用代码编辑器修改
/// 此方法的内容。
/// </summary>
private void InitializeComponent()
{
this.submit.Click += new System.EventHandler(this.SubmitBtn_Click);
this.Load += new System.EventHandler(this.Page_Load);
}
#endregion
}
以上示例简单的说明了ASP.NET的MVC实现,在实际项目中,商务逻辑远远不止这样,但是上述的代码展现了一个基本的模型,在增加了代码和复杂度的同时也带来了显而易见的好处,如:模块依赖的降低、代码重复的减少、职责和问题的分离、代码的可测试性等等。
到现在您是否决定了使用Model-View-Controller (MVC)模式来将动态Web应用程序的用户界面组件与业务逻辑分隔开来,要构建的应用程序将以动态方式构造网页,但是目前的页面导航都是基于静态导航的形式。
在更加复杂的应用系统中,如何考虑尽可能避免导航代码的重复,甚至考虑基于可配置的规则来动态确定页面导航,那么Page Controller和Front Controller某种意义来说是对于MVC模式在更加复杂的系统的优化。