当双值具有小数点时，双值将转换为字符串值

Question

我正在尝试使用CSVHelper库将数据写入MemoryStream，然后使用该MemoryStream生成CSV文件。

问题是当双值具有小数点时，双值将转换为怪异的字符串值。预期的输出和怪异的输出在底部。

有人知道如何克服这个问题吗？还是以下代码中有任何错误？

public class Foo
{
    public Foo()
    {
    }

    public double valOne { get; set; }

    public double valTwo { get; set; }
}

---

public class FooMap : ClassMap<Foo>
{
    public FooMap()
    {
        Map(m => m.valOne).Index(0).Name("Val One");
        Map(m => m.valTwo).Index(1).Name("Val Two");
    }
}

---

var records = new List<Foo> {
    new Foo{valOne = 3224.12, valTwo = 4122},
    new Foo{valOne = 2030.20, valTwo = 5555},
};

var config = new CsvConfiguration(CultureInfo.CurrentCulture) { Delimiter = ",", HasHeaderRecord = true };

using (var memoryStream = new MemoryStream())
using (var writer = new StreamWriter(memoryStream))
using (var csv = new CsvWriter(writer, config))
{
    csv.Context.RegisterClassMap<FooMap>();

    csv.WriteHeader<Foo>();

    csv.NextRecord();
    foreach (var record in records)
    {
        csv.WriteRecord(record);
        csv.NextRecord();
    }

    writer.Flush();
    
    var result = Encoding.UTF8.GetString(memoryStream.ToArray());

    byte[] bytes = Encoding.ASCII.GetBytes(result);

    return new FileContentResult(bytes, "text/csv")
    {
        FileDownloadName = "Sample_Report_Name"
    };
}

预期输出：

Val One, Val Two
3224.12,4122
2030.20,5555

怪异的输出：

Val One, Val Two
"3224,12",4122
"2030,20",5555

Answer 1

问题是运行代码的计算机的当前文化使用逗号而不是时间来指示小数点。使用CultureInfo.InvariantCulture而不是culturenfo.currentcurtulture应解决格式问题。

另外，您可以使用csv.writerecords（Records）来简化代码。

var records = new List<Foo> {
    new Foo{valOne = 3224.12, valTwo = 4122},
    new Foo{valOne = 2030.20, valTwo = 5555},
};

var config = new CsvConfiguration(CultureInfo.CurrentCulture) { Delimiter = ",", HasHeaderRecord = true };

using (var memoryStream = new MemoryStream())
using (var writer = new StreamWriter(memoryStream))
using (var csv = new CsvWriter(writer, config))
{
    csv.Context.RegisterClassMap<FooMap>();

    csv.WriteRecords(records);

    writer.Flush();
    
    var result = Encoding.UTF8.GetString(memoryStream.ToArray());

    byte[] bytes = Encoding.ASCII.GetBytes(result);

    return new FileContentResult(bytes, "text/csv")
    {
        FileDownloadName = "Sample_Report_Name"
    };
}