FileHelpers - 错误转换'“”“ID”“'到类型：'Int32'

Question

The IntValue1 in the csv file is a number without double quotes but when the system reads the row it adds double quotes at the beginning and also double quotes followed by semicolon at the end of the row to delimit the row. Because of this, the IntValue1 starts with a double quotes and the system doesn't recognize it as an int... Please help me to fix this error.

The model:

[DelimitedRecord(",")]
public class MyObject
{
    private int _ID;
    public int ID
    {
        get { return _ID; }
        set { _ID = value; }
    }
    private DateTime _EventDate;
    public DateTime EventDate
    {
        get { return _EventDate; }
        set { _EventDate = value; }
    }
    private string _IPAddress;
    public string IPAddress
    {
        get { return _IPAddress; }
        set { _IPAddress = value; }
    }
}

The code for reading & displaying the data:

private static void GetCsvData()
{
   var engine = new FileHelperEngine<MyTypeObj>();

   //The error occurs at this line:
   var result = engine.ReadFile("C:\\CsvFileName.csv");

   //Code to display the Data
}

The CSV file looks like this:

Content of the row returned by the debugger when the error occurs:

Error:

Answer 1

Problem #1: Your file is not a valid CSV. The proper way to fix this problem would be to correct the way the file is being exported as it is not exporting a valid CSV file.

This is not a valid CSV file:

"ID,""EventDate"",""IPAddress""";
"1,""2013-01-19"",""11.81.11.00""";
"2,""2012-11-25"",""11.72.41.84""";
"3,""2011-12-27"",""15.80.";"3.36"""
"4,""2014-08-17"",""17.72.";"9.24"""
"5,""2012-01-30"",""90.94.27.108""";
"6,""2013-02-15"",""19.97.27.189""";

The Hack: You can use FileHelpers to import invalid CSV files using the BeforeReadRecord event. Sometimes you are just not in control of what CSV file you may receive for importing.

Your Model:

[IgnoreFirst]
[DelimitedRecord(",")]
public class MyTypeObj
{
    [FieldConverter(ConverterKind.Int32)]
    public int ID;

    [FieldQuoted]
    [FieldConverter(ConverterKind.Date, "yyyy-mm-dd")]
    public DateTime EventDate;

    [FieldQuoted]
    public string IPAddress;
}

Your code:

var engine = new FileHelperEngine<MyTypeObj>();

engine.BeforeReadRecord += (@base, args) =>
{
    // Convert this: "1,""2013-01-19"",""11.81.11.00""";
    //      to this: 1,"2013-01-19","11.81.11.00"
    args.RecordLine = args.RecordLine
        .Substring(1, args.RecordLine.Length - 3)
        .Replace("\"\"", "\"");
};

var result = engine.ReadFile(@"C:\CsvFileName.csv");

You will still have problems with these lines (why is there a semi-colon in the middle of the value???):

"3,""2011-12-27"",""15.80.";"3.36"""
"4,""2014-08-17"",""17.72.";"9.24"""

You could also fix these in BeforeReadRecord , but it would be best to figure out what is going wrong with the export.

tl;dr Fix how the file is exported so you get a VALID CSV. Fixing the import should only be an absolute last resort hack.

Answer 2

Looking at the quick start example on the FileHelpers website , their example csv only contains data - not a descriptive first row of data.

I guess when the FileHelperEngine reads the first item of the first row, which is "ID", it will try to convert it to an integer, which fails...