Filling gridview from codebehind

Question

I have a gridview control in my ASP.NET web form. I the past I have used the same code to fill a gridview with data in a Windows Forms App.

Here is my code:

var sql = new SQL_Statements();
var stringSql = "select col1, col2, col3, col4 from table1 where col5=" + stringPO_NUM;
var sql_ds = sql.SelectFromDB(stringSql);
int DataIndex;
if (sql_ds.Tables["CurData"].Rows.Count > 0)
    for (DataIndex = 0; DataIndex <= sql_ds.Tables["CurData"].Rows.Count - 1; DataIndex++)
    {
        sql_ds.Tables["CurData"].Rows[DataIndex]["col4"].ToString();
        //Fill the datagridview with the data that was just pulled from SQL_Statements
        GV_POI.DataSource = sql_ds;
        GV_POI.DataMember = "CurData";
    }

Here is the code for the SelectFromDB:

public DataSet SelectFromDB(String Sql)
        {
            var functionReturnValue = default(DataSet);
            var Class_Connection = new SQL_Connection();
            Class_Connection.cnn.Close(); //Let's close the connection, just in case it is open
            Class_Connection.cnn.Open();                
            var myDataAdaptor = new SqlDataAdapter(Sql, Class_Connection.cnn);
            var myDataset = new DataSet();

            try
            {
                myDataAdaptor.SelectCommand.Connection = Class_Connection.cnn;
                myDataAdaptor.SelectCommand.CommandText = Sql;
                myDataAdaptor.SelectCommand.CommandType = CommandType.Text;
                myDataAdaptor.Fill(myDataset, "CurData");
                functionReturnValue = myDataset;
            }
            catch (Exception ex)
            {
                Console.WriteLine(ex);
                Class_Connection.cnn.Close();
            }
            return functionReturnValue;
            Class_Connection.cnn.Close();
        }

Here is the code for the GridView in the ASPX page:

<asp:GridView ID="GV_POI" runat="server" AutoGenerateColumns="False">
                        </asp:GridView>

I am not sure what I am doing wrong. When the page loads, the gridview is blank. I checked the code in the debugger, and code is firing. Can someone please tell me what I am doing wrong?

Answer 1

If you are getting all data in dataset "sql_ds" then there is no need of for loop , you can do as below

GV_POI.DataSource = sql_ds.Tables[0];
GV_POI.DataBind();

and also either make AutoGenerateColumns="True" or use BoundField or TemplateField.

Example:

<asp:GridView ID="gvTest" runat="server" AutoGenerateColumns="False" GridLines="Vertical"
     OnRowEditing="gvTests_RowEditing"  AllowPaging="True" PageSize="20"
     OnRowDataBound="gvTest_RowDataBound">
<Columns>
<asp:BoundField HeaderText="ID" DataField="ID" ItemStyle-CssClass="hidecss" HeaderStyle-CssClass="hidecss" >
      <ItemStyle Width="80px" HorizontalAlign="Left" />
      <HeaderStyle Width="80px" Wrap="False" />
</asp:BoundField>                           
<asp:BoundField HeaderText="Name" DataField="Name">
      <ItemStyle Width="200px" HorizontalAlign="Left" />
      <HeaderStyle Width="200px" Wrap="False" />
</asp:BoundField>
<asp:BoundField HeaderText="Description" DataField="Description">
      <ItemStyle Width="200px" HorizontalAlign="Left" />
      <HeaderStyle Width="200px" Wrap="False" />
</asp:BoundField>                          
<asp:CommandField ShowEditButton="true" EditImageUrl="~/images/edit.png" ButtonType="Image">
      <HeaderStyle Width="20px" />
      <ItemStyle Width="20px" />
</asp:CommandField>
<asp:TemplateField>
    <ItemTemplate>
      <asp:ImageButton ID="btnDelete" runat="server" CommandName="Delete"
      ImageUrl="~/images/delete.png" AlternateText="Delete"
      ToolTip="Click to Delete"></asp:ImageButton>
    </ItemTemplate>
    </asp:TemplateField>
</Columns>
    <HeaderStyle CssClass="HeaderCss" />
    <PagerStyle CssClass="PagerCss" />                        
    <AlternatingRowStyle CssClass="AltRowCss" />
    <EditRowStyle CssClass="EditRowCss" />
</asp:GridView>