Crystal Report doesn't show data when generated - crystal-reports

Question

When I generate it on runtime, it doesn't show any data. But it does when I check on the 'Main Report Preview' of VS 2010. I have also checked my stored procedure, it does produce data when I execute it. What seems to be the problem?
This is my code in page_load:
protected void Page_Load(object sender, EventArgs e)
{
string municipio = Request.QueryString["municipio"];
string ano = Request.QueryString["ano"];
string cnpj = Server.UrlDecode(Request.QueryString["cnpj"]);
DataTable dt;
string CS = ConfigurationManager.ConnectionStrings["DBCS"].ConnectionString;
using (SqlConnection cnn = new SqlConnection(CS))
{
cnn.Open();
//stored procedure
SqlCommand cmd = new SqlCommand("spConsultaRelatorioCompleto", cnn);
cmd.CommandType = System.Data.CommandType.StoredProcedure;
cmd.Parameters.AddWithValue("#ano", ano);
cmd.Parameters.AddWithValue("#municipio", municipio);
cmd.Parameters.AddWithValue("#cnpj", cnpj);
//read access to the database
SqlDataReader dr = cmd.ExecuteReader();
SqlDataAdapter da = new SqlDataAdapter(cmd);
//datatable with data
dt = new DataTable("dt");
//datatable with datareader's data
dt.Load(dr);
da.Fill(dt);
}
ReportDocument MeuRelatorio = new ReportDocument();
MeuRelatorio.Load(Server.MapPath("RelatorioConvenio.rpt"));
MeuRelatorio.SetDataSource(dt);
CrystalReportViewer1.ReportSource = MeuRelatorio;
}
}
}
I give some values in another webform when I click the button below:
protected void btnExport_Click(object sender, EventArgs e)
{
Response.Redirect("RelatorioGerado.aspx?municipio=" + ddlmunicipioconvenente.Text + "&cnpj=" + Server.UrlEncode(tbcnpjconvenente.Text) + "&ano=" + tbAno.Text);
}