Trace的基本用法(调试技术)_trace late langues-优快云博客

本文链接：https://blog.youkuaiyun.com/greatverve/article/details/3488329

前台

 
 <%@ Page Trace="false" Language="C#" AutoEventWireup="true"  CodeFile="Default.aspx.cs" Inherits="_Default" %>
<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">
<html xmlns="http://www.w3.org/1999/xhtml" >
<head runat="server">
    <title>Trace的基本用法</title>
</head>
<body>
    <form id="form1" runat="server">
    <div>
        <asp:label ID="Label1" runat="server" Text="Tracing,Debuging & Error Handling Demo"></asp:label><br />
        <asp:dropdownlist ID="ddlBooks" runat="server" AutoPostBack="True" OnSelectedIndexChanged="ddlBooks_SelectedIndexChanged">
        </asp:dropdownlist><br />
        <asp:label ID="lblDdl" runat="server" Text="Label"></asp:label>
        <br />
        <asp:hyperlink ID="HyperLink1" runat="server" NavigateUrl="Test.aspx">LinkTo</asp:hyperlink></div>
    </form>
</body>
</html>
 

后台

 
 using System;
using System.Data;
using System.Configuration;
using System.Web;
using System.Web.Security;
using System.Web.UI;
using System.Web.UI.WebControls;
using System.Web.UI.WebControls.WebParts;
using System.Web.UI.HtmlControls;
public partial class _Default : System.Web.UI.Page 
{
    protected void Page_Load(object sender, EventArgs e)
    {
        Trace.Write("in page_load");
        if (!IsPostBack)
        {
            Trace.Write("page_load", "not postback");
            string[,] books ={ 
            {"书名0","0"},
            {"书名1","1"},
            {"书名2","2"}
            };
            int i;
            for (i = 0; i < books.GetLength(0); i++)
            {
                ddlBooks.Items.Add(new ListItem(books[i, 0], books[i, 1]));
            }
        }
    }
    protected void ddlBooks_SelectedIndexChanged(object sender, EventArgs e)
    {
        try
        {
            int a = 0;
            int b = 5 / a;
        }
        catch (System.Exception ex)
        {
            Trace.Warn("useraction", "calling b=5/a", ex);
        }
        if (ddlBooks.SelectedIndex != -1)
        { 
            lblDdl.Text=ddlBooks.SelectedItem.Text+"--->ISBN:"+ddlBooks.SelectedValue;
        }
    }
}
 

结束