CreateDataAdapter函数就在类中,竟显示不存在.

部分代码:
public DataSet RunProcReturn(string procName, string tbName)
{
SqlDataAdapter dap = CreateDataAdaper(procName, null);//错误处
DataSet ds = new DataSet();
dap.Fill(ds, tbName);
this.Close();
return ds;
}

private SqlDataAdapter CreateDataAdaper(string procName, SqlParameter[] prams)
{
this.Open();
SqlDataAdapter dap = new SqlDataAdapter(procName, con);
dap.SelectCommand.CommandType = CommandType.Text;
if (prams != null)
{
foreach (SqlParameter parameter in prams)
{
dap.SelectCommand.Parameters.Add(parameter);
}
}
dap.SelectCommand.Parameters.Add(new SqlParameter("ReturnValue", SqlDbType.Int, 4, ParameterDirection.ReturnValue, false, 0, 0, string.Empty, DataRowVersion.Default, null));
return