Question

我必须解析（C＃）一个.CSV文件，其变量为＆＃34; width＆＃34;和2行标题信息（第一行是名称，第二行是单位）。

数据如下：

Example1.CSV：

"timestamp","NAME_1","NAME_2","NAME_3","NAME_4"
"ms","unit_1","unit_2","unit_3","unit_4"
0.01,1.23,4.56,7.89,0.12
0.02,1.23,4.66,7.89,0.11
0.03,1.23,4.76,7.89,0.11
0.04,56.23,4.86,7.89,0.12

Example2.CSV：

"timestamp","NAME_1","NAME_2","NAME_3","NAME_4","NAME_5",...,"NAME_N"
"ms","unit_1","unit_2","unit_3","unit_4","unit_5",...,"unit_N"
0.01,1.23,4.56,7.89,0.12,0.13,...,0.27
0.02,1.23,4.66,7.89,0.12,0.13,...,0.22
0.03,1.23,4.76,7.89,0.11,0.13,...,0.24
0.04,56.23,4.86,7.89,0.12,0.13,...,0.29

N为＆＃34;宽度＆＃34;表的值（值可以高达128或更大）。我计划使用Filehelpers。

我想过使用[FieldOptional()] - 但这非常不方便，特别是当＆＃34;宽度＆＃34;是可变的......

我目前的尝试看起来像是

[IgnoreFirst(2)]
[DelimitedRecord(",")]
public sealed class LogData
{

    public Double ts;

    public Double Field1;

    [FieldNullValue(0.0)]
    [FieldOptional()]
    public Double Field2;

    [FieldNullValue(0.0)]
    [FieldOptional()]
    public Double Field3;

    // and so on
}

任何帮助＆＃34;如何以更优雅的方式解决变宽＆＃34; -Problem非常感谢 - 非常感谢您提前！

本

Answer 1

如果您打算将文件转换为DataTable，则有更好的选择

请使用FileHelpers库的CsvEngine。请参阅下面的代码段：

using (MemoryStream stream = new MemoryStream(_fileContent)) //file content can be file as byte array
            {
                TextReader reader = new StreamReader(stream);
string path = "C:\\Sample.csv";
                CsvEngine csvEngine = new CsvEngine("Model", ',', path);
                var dataTable = csvEngine.ReadStreamAsDT(reader);
//Do whatever with dataTable

}

此处示例文件可以是csv文件，也可以是包含要处理的csv文件头的文本文件。 DataTable的列将根据示例文件的标题命名

干杯

Answer 2

您可以使用可选的数组字段。我认为你需要使用FileHelpers 2.9.9。

[IgnoreFirst(2)]
[DelimitedRecord(",")]
public class LogData
{
    public Double TimeStamp;

    [FieldNullValue(0.0)]
    [FieldOptional, FieldArrayLength(0, 100)]
    public Double[] ManyFields;
}

这是一个有效的例子。

class Program
{
    static String content = 
         @"""timestamp"",""NAME_1"",""NAME_2"",""NAME_3"",""NAME_4""
         ""ms"",""unit_1"",""unit_2"",""unit_3"",""unit_4""
         0.01,1.23,4.56,7.89,0.12
         0.02,1.23,4.66,7.89,0.11
         0.03,1.23,4.76,7.89,0.11
         0.04,56.23,4.86,7.89,0.12";

    private static void Main()
    {
        var engine = new FileHelperEngine<LogData>();
        var records = engine.ReadString(content);
        Assert.AreEqual(0.01, records[0].TimeStamp);
        Assert.AreEqual(1.23, records[0].ManyFields[0]);
        Assert.AreEqual(4.56, records[0].ManyFields[1]);
        Assert.AreEqual(7.89, records[0].ManyFields[2]);
        Assert.AreEqual(0.12, records[0].ManyFields[3]);
    }
}

filehelpers - 解析变量行长度

2 个答案: