System.Linq.Expressions.Expression<Func<Model.RawMaterialWorkProcess, bool>> ExpWhere = QueryAssembly.True<Model.RawMaterialWorkProcess>();
    if (!string.IsNullOrWhiteSpace(txtNo.Text))
            {
                ExpWhere= ExpWhere.And(a => a.No.Contains(txtNo.Text));
            }
            if (!string.IsNullOrWhiteSpace(txtName.Text))
            {
                ExpWhere = ExpWhere.And(a => a.RMName.Contains(txtName.Text));
            }   
             dgvRawMaterial.DataSource = dt.AsQueryable().Where(ExpWhere).ToList();

QueryAssembly在HSOAR扩展库中