filehelpers - 解析可变长度线(filehelpers - Parsing varia

我要解析（C＃）一个.CSV文件，具有可变的“宽度”和2行的头信息（拳头一个是名称和第二个是该单元）。

数据是这样的：

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

其中N为表中的“宽度”（值可高达128和更大）。 我打算使用Filehelpers 。

我想用的[FieldOptional()] -但会非常不方便，尤其是当“宽度”是可变的...

我现在的尝试看起来像

[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
}

关于“如何解决变宽度” - 问题在一个更优雅的方式感谢任何帮助 - 非常感谢你提前！

Ben

Answer 1:

如果您计划到文件到DataTable中转换，有一个更好的选择

请使用FileHelpers库CsvEngine。 请参见下面的代码片段：

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

}

这里的样本文件可以是CSV文件或文本文件包含要处理的CSV文件的标题。 DataTable的列将根据样品文件的标头被命名

干杯

Answer 2:

您可以使用可选的阵列领域。 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;
}

这里有一个工作示例。

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]);
    }
}

文章来源: filehelpers - Parsing variable line length