List用法
定义一个类：
using System;
using System.Collections.Generic;
using System.Linq;
using System.Web;
namespace WebApplication1
{
[Serializable]
public class Gushi
{
public string Title { get; set; }
public string Content { get; set; }
}
}
/.///////////////前台
<body>
<form id="form1" runat="server">
<div>
<asp:TextBox ID="txtTitle" runat="server" Width="209px"></asp:TextBox>
<asp:Button ID="btnSave" runat="server" Text="保存" onclick="btnSave_Click" />
<asp:Button ID="btnQuery" runat="server" Text="查询" onclick="btnQuery_Click" />
<br />
<br />
<asp:TextBox ID="txtContent" runat="server" Height="219px" TextMode="MultiLine"
Width="339px"></asp:TextBox>
<br />
</div>
</form>
</body>
///////////////////后台
using System;
using System.Collections.Generic;
using System.Linq;
using System.Web;
using System.Web.UI;
using System.Web.UI.WebControls;
namespace WebApplication1
{
public partial class WebGushi : System.Web.UI.Page
{
//List<Gushi> list = new List<Gushi>();
protected void Page_Load(object sender, EventArgs e)
{
}
protected void btnSave_Click(object sender, EventArgs e)
{
Gushi gushi = new Gushi();
gushi.Title = txtTitle.Text;
gushi.Content = txtContent.Text;
//ViewState是一个集合，里面可以纺织任何类型的对象，如int,string,以及我们自己定义的类，如Gushi或者List<Gushi>这种特殊类型的对象。
//判断是不是第一次添加内容，如果是第一次，ViewState中肯定没有任何内容，即为Null；如果不是第一次，则不为Null。
if (ViewState["gushi"] != null)
{
//int i=10;
//将ViewStae中存储的List<Gushi>对象取出来
List<Gushi> list = ViewState["gushi"] as List<Gushi>;
//将新的内容添加到List<Gushi>中
list.Add(gushi);
//下面代码可有可无
ViewState["gushi"] = list;
}
else
{
List<Gushi> list = new List<Gushi>();
list.Add(gushi);
ViewState["gushi"] = list;
}
txtTitle.Text = string.Empty;
txtContent.Text = string.Empty;
}
protected void btnQuery_Click(object sender, EventArgs e)
{
txtContent.Text = string.Empty;
if (ViewState["gushi"] != null)
{
List<Gushi> list = ViewState["gushi"] as List<Gushi>;
//遍历List<Gushi>对象，查询和用户输入的标题相同的古诗，将其内容显示出来
foreach (Gushi item in list)
{
if (item.Title == txtTitle.Text)
{
txtContent.Text = item.Content;
}
}
}
}
}
}
