如何在将数据写入CSV时排除标题

Question

我正在将我的数据从public class写入CSV文件。由于我想追加我的数据，我想排除标头的导入，只从类中导入数据。我的代码下面导入了标题和数据。希望得到帮助。谢谢。

Record.cs - 我的班级

public class Record
{
    public string Name
    {
        get; set;
    }

    public DateTime DateOfBirth
    {
        get; set;
    }
}

Form1.cs - 我的表格

public partial class Form1 : Form
{
    private List<Record> records;

    public Form1()
    {
        InitializeComponent();
        records = new List<Record>();
    }

    private void Savetocsv_Click(object sender, EventArgs e)
    {
        var myDocument = Environment.GetFolderPath(Environment.SpecialFolder.MyDocuments);
        using (var writer = new StreamWriter(myDocument + "/my-data.csv", append: true))
        {
            using (var csv = new CsvWriter(writer))
            {
                csv.WriteRecords(records);
            }                
        }
    }

Answer 1

使用Configuration，您可以使用属性HasHeaderRecord：

HasHeaderRecord：获取或设置一个值，指示CSV文件是否具有标题记录。 默认为true。

var records = new List<Foo>
{
    new Foo { Id = 1, Name = "one" },
    new Foo { Id = 1, Name = "one" },
};

using (var writer = new StreamWriter($"file.csv"))
using (var csv = new CsvWriter(writer, new Configuration { HasHeaderRecord = false }))
{
    csv.WriteRecords(records);
}

结果文件：“file.csv”

1;一个 1;一个

或者只是在记录上循环写入：

var records = new List<Foo>
{
    new Foo { Id = 1, Name = "one" },
    new Foo { Id = 1, Name = "one" }
};

using (var writer = new StreamWriter($"file.csv"))
using (var csv = new CsvWriter(writer))
{
    foreach (var record in records)
    {
        csv.WriteRecord(record);
        csv.NextRecord();
    }
}

Answer 2

改变你的写作方法如下，然后CsvHelper.WriterConfiguration做的伎俩（注意HasHeaderRecord）：

private void Savetocsv_Click(object sender, EventArgs e)
{
    var myDocument = Environment.GetFolderPath(Environment.SpecialFolder.MyDocuments);
    using (var writer = new StreamWriter(myDocument + "/my-data.csv", append: true))
    {
        using (var csv = new CsvWriter(writer, new Configuration { HasHeaderRecord = false }))
        {
            csv.WriteRecords(records);
        }                
    }
}

Answer 3

在调用之前从records中删除第一行：

csv.WriteRecords(records);

（如果您需要保持记录不变，请在调用WriteRecords（...）后再次添加标题。）

private void Savetocsv_Click(object sender, EventArgs e)
{
    var myDocument = Environment.GetFolderPath(Environment.SpecialFolder.MyDocuments);
    using (var writer = new StreamWriter(myDocument + "/my-data.csv", append: true))
    {
        using (var csv = new CsvWriter(writer))
        {
            records.RemoveAt(0);  // Removes the header row.
            csv.WriteRecords(records);
        }                
    }
}

Answer 4

我不知道你使用的是哪个CsvWriter，但是here有一个HasHeaderRecord属性，可以用来忽略或包含标题。

private void Savetocsv_Click(object sender, EventArgs e)
{
    var myDocument = Environment.GetFolderPath(Environment.SpecialFolder.MyDocuments);
    using (var writer = new StreamWriter(myDocument + "/my-data.csv", append: true))
    {
        using (var csv = new CsvWriter(writer))
        {
            csv.Configuration.HasHeaderRecord = true;
            csv.WriteRecords(records);
        }               
    }
}