KJD/AllBase/Extension/Extensions.cs

using NaiBa.Util.Extension;
using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Threading.Tasks;

namespace AllBase.Extension
{
    public static class Extensions
    {
        public static long? ParseToNullableLong(this object obj)
        {
            if (obj == null)
                return null;

            try
            {
                string str = obj.ParseToString();
                if (string.IsNullOrEmpty(str))
                {
                    return null;
                }
                return long.Parse(str);
            }
            catch
            {
                return null;
            }
        }

        public static int? ParseToNullableInt(this object str)
        {
            if (str == null)
                return null;

            try
            {
                return Convert.ToInt32(str);
            }
            catch
            {
                return null;
            }
        }

        public static decimal? ParseToNullableDecimal(this object str)
        {
            try
            {
                if (str == null)
                    return null;
                return decimal.Parse(str.ToString());
            }
            catch
            {
                return null;
            }
        }

        public static DateTime? ParseToNullableDateTime(this string str)
        {
            try
            {
                if (string.IsNullOrWhiteSpace(str))
                {
                    return null;
                }
                if (str.Contains("-") || str.Contains("/"))
                {
                    return DateTime.Parse(str);
                }
                else
                {
                    int length = str.Length;
                    switch (length)
                    {
                        case 4:
                            return DateTime.ParseExact(str, "yyyy", System.Globalization.CultureInfo.CurrentCulture);
                        case 6:
                            return DateTime.ParseExact(str, "yyyyMM", System.Globalization.CultureInfo.CurrentCulture);
                        case 8:
                            return DateTime.ParseExact(str, "yyyyMMdd", System.Globalization.CultureInfo.CurrentCulture);
                        case 10:
                            return DateTime.ParseExact(str, "yyyyMMddHH", System.Globalization.CultureInfo.CurrentCulture);
                        case 12:
                            return DateTime.ParseExact(str, "yyyyMMddHHmm", System.Globalization.CultureInfo.CurrentCulture);
                        case 14:
                            return DateTime.ParseExact(str, "yyyyMMddHHmmss", System.Globalization.CultureInfo.CurrentCulture);
                        default:
                            return DateTime.ParseExact(str, "yyyyMMddHHmmss", System.Globalization.CultureInfo.CurrentCulture);
                    }
                }
            }
            catch
            {
                return null;
            }
        }
    }
}