基于SqlSugar的开发框架循序渐进介绍（24）-- 使用Serialize.Linq对Lambda表达式进行序列化和反序列化

/// <summary>
/// 新增状态下的数据保存
/// </summary>
/// <returns></returns>
public async override Task<bool> SaveAddNew()
{
    CustomerInfo info = tempInfo;//必须使用存在的局部变量，因为部分信息可能被附件使用
    SetInfo(info);
    try
    {
        #region 新增数据
        //检查是否还有其他相同关键字的记录
        bool isExist = await BLLFactory<ICustomerService>.Instance.IsExistAsync(s=> s.Name.Equals(info.Name));
        if (isExist)
        {
            MessageDxUtil.ShowTips("指定的【姓名】已经存在，不能重复添加，请修改");
            return false;
        }
        var success = await BLLFactory<ICustomerService>.Instance.InsertAsync(info);
        if (success)
        {
            //可添加其他关联操作
            return true;
        }
        #endregion
    }
    catch (Exception ex)
    {
        LogTextHelper.Error(ex);
        MessageDxUtil.ShowError(ex.Message);
    }
    return false;
}

/// <summary>
/// 判断是否存在指定条件的记录
/// </summary>
/// <param name="input">表达式条件</param>
/// <returns></returns>
Task<bool> IsExistAsync(Expression<Func<TEntity, bool>> input);

/// <summary>
/// 初始化数据字典
/// </summary>
private async void InitDictItem()
{
    //初始化代码            
    var list = await BLLFactory<IFormService>.Instance.GetFieldList(s=> s.Category);
    this.txtCategory.BindDictItems(list, "");
}

/// <summary>
/// 初始化数据字典
/// </summary>
private async void InitDictItem()
{
    //初始化代码            
    var list = await BLLFactory<IFormService>.Instance.GetFieldList(s=> s.Category);
    this.txtCategory.BindDictItems(list, "");
}

/// <summary>
    /// 对Lambda表达式的序列号和反序列化处理
    /// </summary>
    public static class SerializeExtension
    {
        /// <summary>
        /// 序列化 LINQ Expression 表达式为JSON文本
        /// </summary>
        /// <typeparam name="TEntity">处理对象类型</typeparam>
        /// <typeparam name="TResult">返回结果类型</typeparam>
        /// <param name="express"></param>
        /// <returns></returns>
        public static string SerializeText<TEntity, TResult>(this Expression<Func<TEntity, TResult>> express)
        {
            //使用Serialize.Linq组件序列化表达式，传递给API端，API端需要对应反序列化的处理操作进行转换Expression
            var serializer = new ExpressionSerializer(new JsonSerializer());
            var expressJson = serializer.SerializeText(express);
            //接收端的反序列化处理
            //var express = (Expression<Func<TEntity, TResult>>)serializer.DeserializeText(expressJson);
            return expressJson;
        }
        /// <summary>
        /// 反序列化JSON文本为LINQ Expression 表达式
        /// </summary>
        /// <typeparam name="TEntity">处理对象类型</typeparam>
        /// <typeparam name="TResult">返回结果类型</typeparam>
        /// <param name="text"></param>
        /// <returns></returns>
        public static Expression<Func<TEntity, TResult>> DeserializeText<TEntity, TResult>(this string json)
        {
            Expression<Func<TEntity, TResult>> express = null;
            if (!string.IsNullOrWhiteSpace(json))
            {
                var serializer = new ExpressionSerializer(new JsonSerializer());
                express = (Expression<Func<TEntity, TResult>>)serializer.DeserializeText(json);
            }
            return express;
        }
    }

/// <summary>
        /// 根据条件，获取所有记录
        /// </summary>
        public virtual async Task<ListResultDto<TEntity>> GetAllAsync(Expression<Func<TEntity, bool>> input, string orderBy = null)
        {
            var express = input.SerializeText(); //使用扩展函数处理生成JSON
            var postData = new
            {
                express,
                orderBy
            };
            return await DoActionAsync<ListResultDto<TEntity>>("all-expression", postData, HttpVerb.Post);
        }
        /// <summary>
        /// 根据条件计算记录数量
        /// </summary>
        /// <returns></returns>
        public virtual async Task<long> CountAsync(Expression<Func<TEntity, bool>> input)
        {
            var expressJson = input.SerializeText(); //使用扩展函数处理生成JSON
            return await DoActionAsync<long>("count-expression", expressJson, HttpVerb.Post);
        }

/// <summary>
        /// 根据条件，获取所有记录
        /// </summary>
        [HttpPost]
        [Route("all-expression")]
        public async Task<ListResultDto<TEntity>> GetAllAsync(ExpressionOrderDto input)
        {
            ListResultDto<TEntity>? result = null;
            string json = input.expression;
            var express = json.DeserializeText<TEntity, bool>();
            if (express != null)
            {
                result = await _service.GetAllAsync(express!);
            }
            return result;
        }
        [HttpPost]
        [Route("count-expression")]
        public virtual async Task<long> CountAsync(dynamic expressJson)
        {
            long result = 0;
            string json = expressJson;
            var express = json.DeserializeText<TEntity, bool>();
            if (express != null)
            {
                result = await _service.CountAsync(express!);
            }
            return result;
        }