Express对条件的手动拼接

 

 

 

 

   ///查询数据库的仓储类
            ItestRepository test = new TestRepository();
            ParameterExpression parameterExpression = Expression.Parameter(typeof(Test), "d");

            PropertyInfo IdProp = typeof(Test).GetProperty("Id");
            MemberExpression IdPropExp = Expression.Property(parameterExpression, IdProp);

            MethodInfo equals = typeof(int).GetMethod("Equals", new Type[1]{

                typeof(int)
                });
            ConstantExpression constant = Expression.Constant(1);

            var tt = Expression.Call(IdPropExp, equals, constant);

            Expression<Func<Test, bool>> pre = Expression.Lambda<Func<Test, bool>>(
                tt, new ParameterExpression[1]
                {
                    parameterExpression
                }
                );
            var where = pre.Compile();
            var end = test.FindAll(where);