YLShipBuildLandMap/YLShipBuildLandMap.Services/SystemSetting/ParameterServices.cs

using Bowin.Common.Utility;
using YLShipBuildLandMap.Entity;
using Microsoft.EntityFrameworkCore;
using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Threading.Tasks;

namespace YLShipBuildLandMap.Services.SystemSetting
{
    public class ParameterServices : IParameterServices
    {
        private YLShipBuildLandMapContext DbContext { get; set; }

        public ParameterServices(YLShipBuildLandMapContext dbContext)
        {
            DbContext = dbContext;
        }

        public async Task<Nullable<T>> GetParameterValue<T>(string parameterKey) where T : struct
        {
            var parameter = await DbContext.SysParameter.FirstOrDefaultAsync(x => x.ParameterKey == parameterKey);

            if (parameter == null || string.IsNullOrEmpty(parameter.Value)) return null;
            T result;
            if (parameter.Value.TryParseTo(out result))
            {
                return result;
            }
            return null;
        }

        public async Task<string> GetParameterValue(string parameterKey)
        {
            var parameter = await DbContext.SysParameter.FirstOrDefaultAsync(x => x.ParameterKey == parameterKey);

            if (parameter == null || string.IsNullOrEmpty(parameter.Value)) return null;
            return parameter.Value;
        }

        public async Task SaveTo(string parameterKey, object value)
        {
            var parameter = await DbContext.SysParameter.FirstOrDefaultAsync(x => x.ParameterKey == parameterKey);

            if (parameter == null)
            {
                parameter = new SysParameter();

                parameter.ParameterKey = parameterKey;
                if (value != null)
                {
                    parameter.Value = value.ToString();
                }
                else
                {
                    parameter.Value = null;
                }

                this.DbContext.Add(parameter);
            }
            else
            {
                if (value != null)
                {
                    parameter.Value = value.ToString();
                }
                else
                {
                    parameter.Value = null;
                }
            }

            await this.DbContext.SaveChangesAsync();
        }
    }
}