将Gridview数据保存到数据库

Question

I am having a Gridview which i want to save in my another table

My Code is

protected void upload_Click(object sender, EventArgs e)
{
    string query1 = "INSERT INTO tbl_Pre_Y1_Bus1 (CRITICAL,SPECIFICATION, [1],[2],[3],[4],[5],TMLCAL) VALUES (@CRITICAL, @SPECIFICATION, @[1], @[2], @[3], @[4], @[5], @TMLCAL)";

    foreach (GridViewRow row in GridView2.Rows)
    {
        using (SqlCommand cmd = new SqlCommand(query1))
        {
            cmd.Connection = con;
            cmd.CommandType = CommandType.Text;

            cmd.Parameters.AddWithValue("@CRITICAL", row.Cells[0].ToString());
            cmd.Parameters.AddWithValue("@SPECIFICATION", row.Cells[1].ToString());
            cmd.Parameters.AddWithValue("@[1]", row.Cells[2].ToString());
            cmd.Parameters.AddWithValue("@[2]", row.Cells[3].ToString());
            cmd.Parameters.AddWithValue("@[3]", row.Cells[4].ToString());
            cmd.Parameters.AddWithValue("@[4]", row.Cells[5].ToString());
            cmd.Parameters.AddWithValue("@[5]", row.Cells[6].ToString());
            cmd.Parameters.AddWithValue("@TMLCAL",row.Cells[7].ToString());
         con.Open(); //here i am having an respected error
         cmd.ExecuteNonQuery();
         con.Close();
         Page.Response.Redirect(Page.Request.Url.ToString(), true);
        }

    }
}

My error is "Object reference not set to an instance of an object." help me to resolve this

Answer 1

Replace .ToString() with Convert.ToString as shown below. It will handle blank as well as null value. Then you can check why the value is coming null. You also need to add .Text as shown below.

cmd.Parameters.AddWithValue("@CRITICAL", Convert.ToString(row.Cells[0].Text));
cmd.Parameters.AddWithValue("@SPECIFICATION", Convert.ToString(row.Cells[1].Text));

Answer 2

Before calling .ToString() make sure that your object is not null, Also to read cell text you must put .Text Something like this :

    if (row.Cells[0] != null && !string.IsNullOrEmpty(row.Cells[0].Text)) {
     cmd.Parameters.AddWithValue("@CRITICAL", row.Cells[0].Text.ToString());

    } else {
     // Handle it
    }