CODEWITHSUNDEEP
c#asp.netgridview
user5547019
user5547019

Reputation:

Error: The type specified in the TypeName property of ObjectDataSource could not be found

I've got a Datatable with a Sql Connection and am trying to bind that to a GridView, however I get the error that the type specified in the TypeName property could not be found. My datatable code looks like this :

 protected void ObjectDataSource1_Selecting(object sender, ObjectDataSourceSelectingEventArgs e)
{


    if (!IsPostBack)
    {

        SqlConnection conn = new SqlConnection();
        conn.ConnectionString = "TestConnectionString";

        SqlCommand command = new SqlCommand();
        command.Connection = conn;
        command.CommandText = "SELECT* FROM TestTable";

        DataTable data = new DataTable();

        SqlDataAdapter adapter = new SqlDataAdapter(command);

        adapter.Fill(data);

        GridView1.DataSource = data;

    }

and the code in the .aspx :

 <asp:GridView ID="GridView1" runat="server" AllowSorting="True" AutoGenerateColumns="False" DataSourceID="ObjectDataSource1" >
        <Columns>
            <asp:BoundField DataField="Column1" HeaderText="Column1" ReadOnly="True" SortExpression="Column1" >
            <HeaderStyle Width="450px" />
            <ItemStyle HorizontalAlign="Center" />
            </asp:BoundField>
            <asp:BoundField DataField="Column2" HeaderText="Column2" ReadOnly="True" SortExpression="Column2" >
                <ItemStyle Width="400px" HorizontalAlign="Center" />
                </asp:BoundField>
        </Column>

    </asp:GridView>
   <asp:ObjectDataSource ID="ObjectDataSource1" runat="server" SelectMethod="DataTable" TypeName="data"></asp:ObjectDataSource>

Suggestions on what I've done wrong?

Upvotes: 1

Views: 2559

Answers (1)

Richard Deeming
Richard Deeming

Reputation: 31198

That's not how the ObjectDataSource control is meant to be used.

If you just want to bind the grid on the first page load, then remove the ObjectDataSource control, remove the ObjectDataSource1_Selecting event handler, remove the DataSourceID property from the GridView, and just bind the grid when the page loads:

protected void Page_Load(object sender, EventArgs e)
{
    if (!IsPostBack)
    {
        BindGrid();
    }
}

private void BindGrid()
{
    using (SqlConnection conn = new SqlConnection("your connection string here"))
    using (SqlCommand command = new SqlCommand("SELECT * FROM TestTable", conn))
    {
        DataTable data = new DataTable();
        SqlDataAdapter adapter = new SqlDataAdapter(command);
        adapter.Fill(data);

        GridView1.DataSource = data;
        GridView1.DataBind();
    }
}

If you want to use the ObjectDataSource control, then give it a valid TypeName and SelectMethod, remove the ObjectDataSource1_Selecting event handler, and have the SelectMethod return the data:

public static class YourDataSource
{
    public static DataTable LoadSomeData()
    {
        using (SqlConnection conn = new SqlConnection("your connection string here"))
        using (SqlCommand command = new SqlCommand("SELECT * FROM TestTable", conn))
        {
            DataTable data = new DataTable();
            SqlDataAdapter adapter = new SqlDataAdapter(command);
            adapter.Fill(data);
            return data;
        }
    }
}

Markup:

<asp:ObjectDataSource ID="ObjectDataSource1" runat="server"
    TypeName="YourDataSource"
    SelectMethod="LoadSomeData" 
/>

If you're using .NET 4.5, you could also use "model binding" to load the data from the code-behind without using a data-source control:

public DataTable LoadSomeData()
{
    using (SqlConnection conn = new SqlConnection("your connection string here"))
    using (SqlCommand command = new SqlCommand("SELECT * FROM TestTable", conn))
    {
        DataTable data = new DataTable();
        SqlDataAdapter adapter = new SqlDataAdapter(command);
        adapter.Fill(data);
        return data;
    }
}

Markup:

<asp:GridView ID="GridView1" runat="server" 
    AllowSorting="True" 
    AutoGenerateColumns="False"
    SelectMethod="LoadSomeData"
>
<Columns>
    ...
</Columns>
</asp:GridView>

Upvotes: 2

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