调试时的Epplus Save()，SaveAs()等的操作非常缓慢

Question

环境-Windows 10，Visual Studio 2017，NetCore2.0，调试构建。

使用Epplus 4.1.1保存Excel文件时，在调试时，保存操作需要比我预期的更长的时间。

与调试 ->开始调试

时，这是一些时间。

Saving 100 rows in 2065ms.
Saving 200 rows in 2050ms.
Saving 400 rows in 4003ms.
Saving 800 rows in 11360ms.
Saving 1600 rows in 18377ms.
Saving 3200 rows in 34139ms.

与debug一起运行时相同 ->启动而无需调试

Saving 100 rows in 401ms.
Saving 200 rows in 49ms.
Saving 400 rows in 28ms.
Saving 800 rows in 58ms.
Saving 1600 rows in 94ms.
Saving 3200 rows in 198ms.

定位.NET框架4.6.1时，调试时的结果要好得多 -

Saving 100 rows in 215ms.
Saving 200 rows in 26ms.
Saving 400 rows in 42ms.
Saving 800 rows in 78ms.
Saving 1600 rows in 146ms.
Saving 3200 rows in 279ms.

我显然知道调试是糖蜜缓慢的，但这是一个很少的数据。在调试目标.NET CORE 2.0时，我可以做些什么来戳戳以更快的速度？

-

这是产生上述输出的程序 -

namespace ConsoleApp9
{
    using System;
    using System.Collections.Generic;
    using System.IO;
    using System.Text;
    using System.Linq;
    using System.Diagnostics;
    using OfficeOpenXml;
    public class Foo
    {
        public string Name { get; set; }
        public int Number { get; set; }
        public char? Character { get; set; }
    }
    class Program
    {
        static void Main(string[] args)
        {
            Encoding.RegisterProvider(CodePagesEncodingProvider.Instance);
            IEnumerable<Foo> RandomFoo()
            {
                var random = new Random();
                const string chars = "ABCDEFGHIJKLH";
                while (true)
                {
                    yield return new Foo
                    {
                        Character = random.NextDouble() < .1 ? null : (char?) 'A',
                        Number = random.Next(0, 10),
                        Name = new string(Enumerable.Repeat(chars, 8)
                            .Select(x => x[random.Next(x.Length)])
                            .ToArray()
                        )
                    };
                }
            }
            for (var i = 100; i <= 1000000; i *= 2)
            {
                var sw = Stopwatch.StartNew();
                var stream = new MemoryStream();
                using (var package = new ExcelPackage(stream))
                {
                    var sheet = package.Workbook.Worksheets.Add("Sheet");
                    var foos = RandomFoo().Take(i);
                    sheet.Cells["A1"].LoadFromCollection(foos);
                    package.Save(); // very long operation here
                    stream.Seek(0, SeekOrigin.Begin);
                }
                var file = new FileInfo("test.xlsx");
                using (var fileStream = file.Create())
                {
                    stream.CopyTo(fileStream);
                }
                Console.WriteLine($"Saving {i} rows in {sw.ElapsedMilliseconds}ms.");
            }
        }
    }
}

Answer 1

epplus v4.4.1不完全.net core 2兼容，但我仍然有与您的数字不同（逻辑上的数字）。

Saving 100 rows in 360ms.
Saving 200 rows in 23ms.
Saving 400 rows in 48ms.
Saving 800 rows in 84ms.
Saving 1600 rows in 183ms.
Saving 3200 rows in 317ms.
Saving 6400 rows in 592ms.
Saving 12800 rows in 1157ms.
Saving 25600 rows in 2352ms.
Saving 51200 rows in 4848ms.
Saving 102400 rows in 9613ms.
Saving 204800 rows in 18917ms.

我建议您使用.NET Core 2兼容预释放环境

这是我使用Epplus v4.5.0.1-beta在Windows 10，Visual Studio 2017，NetCore2.0，Debug Build中获得的数字。

Saving 100 rows in 585ms.
Saving 200 rows in 114ms.
Saving 400 rows in 125ms.
Saving 800 rows in 159ms.
Saving 1600 rows in 233ms.
Saving 3200 rows in 360ms.
Saving 6400 rows in 655ms.
Saving 12800 rows in 1251ms.
Saving 25600 rows in 2422ms.
Saving 51200 rows in 4840ms.
Saving 102400 rows in 9789ms.
Saving 204800 rows in 19094ms.
Saving 409600 rows in 38093ms.

Answer 2

i也有相同的问题，这是因为我在单元格中存储了字符值：worksheet.cells [i，j] .value ='a';它正在工作，但是保存时会产生转换铸件异常，从而减慢了很多与调试器。只需存储一个字符串！worksheet.cells [i，j] .value =" a";