asp.net gridview不显示数据

Question

protected void Button1_Click1(object sender, EventArgs e)
{
    SqlConnectionStringBuilder connb = new SqlConnectionStringBuilder(ConfigurationManager.ConnectionStrings["SCS"].ConnectionString);      
    using (SqlConnection conn = new SqlConnection(connb.ConnectionString))
    {
        SqlCommand cmd = new SqlCommand("Select * from dbo.Users;", conn);
        DataTable tb = new DataTable();

        SqlDataAdapter da = new SqlDataAdapter(cmd);

        da.Fill(tb);
        tb.AcceptChanges();
        GridView1.DataSource = tb;
        GridView1.DataBind();
     }
}

This is my code in C# asp.net application. I want to display SQL table in gridview.

<Columns>
  <asp:BoundField ItemStyle-Width="150px" DataField="name" HeaderText="name" />
  <asp:BoundField ItemStyle-Width="150px" DataField="lastname" HeaderText="lastname" />
  <asp:BoundField ItemStyle-Width="150px" DataField="ID" HeaderText="ID" />
</Columns>

IT shows empty gridview(When I press button1). It doesn't shows any error message. Connection string works, SQL command affects rows, But it still doesn't show any data on gridview!!!

Can anyone help me?

Answer 1

DataSet ds = new DataSet();
SqlDataAdapter da = new SqlDataAdapter(cmd);

da.Fill(ds);

GridView1.DataSource = ds.Tables[0];
GridView1.DataBind();

Answer 2

Seems like your query never gets executed

cmd.ExecuteNonQuery () 

This should have happened before this line

SqlDataAdapter da = new SqlDataAdapter(cmd); 

Answer 3

You could be getting exception in DataBind() - use a try-catch block. This could happen due to a missing column in the DataTable that is being used in a bound field.

 protected void Button1_Click1(object sender, EventArgs e)
 {

   SqlConnectionStringBuilder connb = new SqlConnectionStringBuilder(ConfigurationManager.ConnectionStrings["SCS"].ConnectionString);
   using (SqlConnection conn = new SqlConnection(connb.ConnectionString))
   {
    try
    {
      SqlCommand cmd = new SqlCommand("Select * from dbo.Users;", conn);
      DataTable tb = new DataTable();

      SqlDataAdapter da = new SqlDataAdapter(cmd);

      da.Fill(tb);
      tb.AcceptChanges();
      GridView1.DataSource = tb;
      GridView1.DataBind();
      GridView1.Rows[0].Cells[0].Text. = "a";
    }
    catch(Exception ex)
    {
         Response.Write(ex.Message);
    }     
   }           
}

Answer 4

• You should set AutoGenerateColumns="false" , if you want to bind specify column.Please check it

• And also need to check have you set visible="false" or style="display:none" in your gridview

• And check DataField must matched the table column name

Answer 5

I had a problem where I was getting data in the datasource and the GridView wasn't showing up at all. I had AutoGenerateColumns = "true" in the Gridview definition on the page. For some reason, when I set up a breakpoint and looked at the properties of the Gridview in the code behind, it was still set to false. I set it to true in the code behind before setting the Gridview equal to the datasource and doing the databind. That worked.

Answer 6

       SqlCommand cmd = new SqlCommand("Select * from dbo.Users;", conn);
       SqlDataAdapter da = new SqlDataAdapter(cmd);      
       ds = new DataSet();
       da.Fill(ds, "usersdata");
       GridView1.DataSource = ds.Tables["usersdata"];
       GridView1.DataBind();