利用Ajax技术写一个迷你留言板WEB控件

<%@ Control Language="C#" ClassName="MiniGB" %>
<%@ Import Namespace="System.Data.OleDb" %>
<%@ Import Namespace="System.Data" %>

<script runat="server">
   
 
    private OleDbConnection conn = new OleDbConnection("provider=microsoft.jet.oledb.4.0;data source="+System.Web.HttpContext.Current.Server.MapPath("guest.mdb"));
    private string dname = "游客";
    public string Dname
    {
        get
        {
            return dname;
        }
        set
        {
            dname = value;
        }
    }
   
    protected void Button1_Click(object sender, EventArgs e)
    {
        if (TextBox1.Text.Trim() != "")
        {
            OleDbCommand comm = new OleDbCommand("insert into guest(name,content)values('"+dname+"','" + TextBox1.Text.Trim() + "')", conn);
            comm.ExecuteNonQuery();
            listupdate();
            TextBox1.Text = "";
        }
    }
    private void listupdate()
    {
        OleDbDataAdapter da = new OleDbDataAdapter("select top 5 * from guest order by id desc", conn);
        DataSet ds = new DataSet();
        da.Fill(ds);
        DataList1.DataSource = ds;
        DataList1.DataBind();
    }
    protected void Page_Load(object sender, EventArgs e)
    {
        conn.Open();
        listupdate();
    }
</script>
<style>
.Gtitle
{
width:200px;
background-color:#464646;
color:#FFFFFF;
font-size:14px;
height:20px;
padding: 3px 0 0 10px;
font-weight:bold;
border-style:solid;
border-top-width:1px;
border-bottom-width:0px;
border-left-width:1px;
border-right-width:1px;
border-color:#BBBBBB;
}
.Gbody
{
width:200px;
border-style:solid;
border-top-width:0px;
border-bottom-width:0px;
border-left-width:1px;
border-right-width:1px;
border-color:#BBBBBB;
padding:3px 5px 3px 5px;
}
.Gend
{
width:200px;
border-style:solid;
border-top-width:0px;
border-bottom-width:1px;
border-left-width:1px;
border-right-width:1px;
border-color:#BBBBBB;
padding:3px 5px 3px 5px;

}
.Gname
{
width:190px;
 font-size:12px;
 color:blue;

}
.Gcontent
{
width:190px;
word-break:break-all;
color:#444444;
font-size:12px;
padding: 3px 0 3px 0;
border-style:dotted;
border-top-width:0px;
border-bottom-width:1px;
border-left-width:0px;
border-right-width:0px;
border-color:#BBBBBB;
}
</style>

<asp:ScriptManagerProxy ID="ScriptManagerProxy1" runat="server">
</asp:ScriptManagerProxy>
<asp:UpdatePanel ID="UpdatePanel1" runat="server">
    <ContentTemplate>
        <div class="Gtitle"><asp:Label ID="Label1" runat="server" Text="留言板"></asp:Label></div>
        <div class="Gbody"><asp:DataList ID="DataList1" runat="server" >
        <ItemTemplate>
        <div class="Gname"><%# DataBinder.Eval(Container.DataItem, "name") %> 说：</div><div class="Gcontent"><%# DataBinder.Eval(Container.DataItem, "content") %></div>
        </ItemTemplate>
        </asp:DataList></div>
        <div class="Gend"><asp:TextBox ID="TextBox1" runat="server" Width="150px" />
        <asp:Button ID="Button1" runat="server" Text="留言" OnClick="Button1_Click" /></div>
    </ContentTemplate>
</asp:UpdatePanel>