即使没有错误，我也无法使用数据显示gridview。为什么？ [英] I couldn't display gridview with data even there is no error. Why?

问题描述

我在一个带有SQLSERVER2008的webform中尝试了一个非常基本的数据绑定..所有东西似乎都很完美（没有错误），但是当它运行时仍然无法在浏览器上显示它...我什么也看不见jus一个空白的页面。

有什么不对的？

-i lookupon db连接它的罚款

I tried a very basic databinding in a webform with SQLSERVER2008..everything seems to be perfect(NO ERRORS),but still couldn't display it on browser while it runs..i see nothing jus a blank page.
What could be wrong?
-i lookedupon db connection its fine

using System;
using System.Collections.Generic;
using System.Linq;
using System.Web;
using System.Web.UI;
using System.Web.UI.WebControls;
using System.Data.Sql;
using System.Data.SqlClient;
public partial class _Default : System.Web.UI.Page
{
    protected void Page_Load(object sender, EventArgs e)
    {

    }
    protected void GridView1_SelectedIndexChanged(object sender, EventArgs e)
    {
        SqlConnection con =new SqlConnection ("data source=.; database=sample ; integrated security=SSPI; ");
        SqlCommand cmd = new SqlCommand("Select * from Login_Info", con);
        con.Open();
        SqlDataReader rdr = cmd.ExecuteReader();
        GridView1.DataSource = rdr;
        GridView1.DataBind();
        con.Close();
    }
}

推荐答案

你绑定 GridView 在同一 GridView 的 SelectedIndexChanged 事件中。由于网格没有任何数据，该事件永远不会触发。



尝试从 Page_Load 事件而不是。你还想把它包装在 if（！IsPostBack）{...} 块中。





You're binding the GridView in the SelectedIndexChanged event for the same GridView. Since the grid doesn't have any data, that event will never fire.

Try binding the grid from the Page_Load event instead. You'll also want to wrap it in an if (!IsPostBack) { ... } block.

using System;
using System.Data.SqlClient;

public partial class _Default : System.Web.UI.Page
{
    protected void Page_Load(object sender, EventArgs e)
    {
        if (!IsPostBack)
        {
            BindTheGrid();
        }
    }

    private void BindTheGrid()
    {
        using (SqlConnection con = new SqlConnection ("data source=.; database=sample ; integrated security=SSPI; "))
        using (SqlCommand cmd = new SqlCommand("Select * from Login_Info", con))
        {
            con.Open();
            using (SqlDataReader rdr = cmd.ExecuteReader())
            {
                GridView1.DataSource = rdr;
                GridView1.DataBind();
            }
        }
    }
}

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