Notsupportedexception error when setting value to a Datasource

Question

I have a textbox and want, when typing something, the datasource of my gridFornecedor be updated.

I’m using the code below:

private void txtNome_TextChanged(object sender, EventArgs e)
{
    gridFornecedor.DataSource = modelOff.fornecedors.Where(p => p.nome.Contains(txtNome.Text));
}

I get the error below:

Answer 1

The problem is written in the error, the return of its expression is a query and not concrete data.

Call .ToList() to materialize the data

gridFornecedor.DataSource = modelOff.fornecedors
                                    .Where(p => p.nome.Contains(txtNome.Text)).ToList();

Notice that using the event TextChanged you are causing the data to be searched in the each key the user presses. This can be extremely problematic if there is a considerable amount of data. Maybe it’s a good idea to think a little better and do it in a more appropriate way.

Answer 2

You need to materialize the return of the database data through a conversion to an object or collection. Following the suggestion of the error message, try calling the method ToList() after applying the Where:

private void txtNome_TextChanged(object sender, EventArgs e)
{
    gridFornecedor.DataSource = modelOff.fornecedors.Where(p => p.nome.Contains(txtNome.Text)).ToList();
}