如何解析csv文件中的空值并在c#中初始化为默认值？

Question

我正在尝试从CSV文件中读取数据，但是我的CSV文件有许多空单元格用于不同的列。因此，我希望捕获这些空单元格，并将这些空值初始化为默认值-1。我试图遍历这些值，但由于某些原因，它部分有效，部分无效。我能做错什么呢？

//Some of the columns are still empty even though they were supposed to 
//initialized to -1. While some others are initialized to -1.

public class DPdfView
{
    public DPdfView()
    {
        //ReadExcel("t.csv");
    }

    public String ReadCSV()
    {
        String cont = null;
        using (TextFieldParser parser = new TextFieldParser("t.csv"))
        {
            parser.TextFieldType = FieldType.Delimited;
            parser.SetDelimiters(",");
            while (!parser.EndOfData)
            {
                //Processing row
                string[] fields = parser.ReadFields();

                for (int i = 0; i < fields.Length; i++)
                {
                    if (fields[i].Length == 0)
                    {
                        fields[i] = "\n" + "-1";
                    }
                    //Console.WriteLine(fields[4]);
                }
                String Value_DATE = fields[2];
                String Booking_Date = fields[3];
                String Transaction = fields[4];
                String Reference = fields[7];
                String Money_Out = fields[8];
                String Money_In = fields[9];
                String Balance = fields[14];
                cont = cont + Value_DATE + "\n" + Booking_Date + "\n" + Transaction + "\n" + Reference + "\n" + Money_Out + "\n" + Money_In + "\n" + Balance;
            }
        }
        return cont;
    }
}

//根据m.rogalski的建议，这就是我所得到的。-1被附加到同一行，而不是附加到下一行。

VALUE_DATE
BOOKING_DATE
TRANSACTION
REFERENCE
MONEY.OUT
MONEY.IN
AVAILABLE.BALANCE-1 // the -1 should be appended to the next line
2847899
KES
-1
10/10/2016
9/11/2016
5403.759/11/2016
9/11/2016
Opening Balance
-1
-1
-1
-112/10/2016
12/10/2016
Mobile Mpesa Transfer
-1
1533
-1
-117-10-2016
17-10-2016
ATM Withdrawal
6.29006E+11
1000
-1
-117-10-2016
17-10-2016
ATM Withdrawal
6.29118E+11
2000
-1
-117-10-2016
17-10-2016
Mobile Mpesa Transfer
-1
2083
-1
-117-10-2016
17-10-2016
Transfer from Mpesa
-1
0
4000
-118-10-2016
18-10-2016
Mobile Mpesa Transfer
-1
333
-1
-118-10-2016
18-10-2016
Mobile Mpesa Transfer
-1
733
-1
-121-10-2016
21-10-2016
ATM Withdrawal
5.04158E+15
1000
-1
-121-10-2016
21-10-2016
Mobile Mpesa Transfer
-1
433
-1
-121-10-2016
21-10-2016
Mobile Mpesa Transfer
-1
883
-1
-121-10-2016
21-10-2016
Transfer from Mpesa
-1
0
5000
-124-10-2016
24-10-2016
Mobile Mpesa Transfer
-1
1583
-1
-124-10-2016
24-10-2016
Mobile Mpesa Transfer
-1
2033
-1
-125-10-2016
25-10-2016
Mobile Internal Transfer
-1
10000
-1
-125-10-2016
25-10-2016
Mobile Mpesa Transfer
-1
2033
-1
-125-10-2016
25-10-2016
Mobile Mpesa Transfer
-1
373
-1
-125-10-2016
25-10-2016
Mobile Mpesa Transfer
-1
50983
-1
-127-10-2016
27-10-2016
Mobile Mpesa Transfer
-1
1183
-1
-128-10-2016
28-10-2016
ATM Withdrawal
5.04158E+15
20000
-1
-128-10-2016
28-10-2016
Mobile Mpesa Transfer
-1
1333
-1
-131-10-2016
31-10-2016
Mobile Mpesa Transfer
-1
783
-1
-11/11/2016
1/11/2016
Mobile Mpesa Transfer
-1
4533
-1
-11/11/2016
1/11/2016
Transfer from Mpesa
-1
0
3650
-12/11/2016
2/11/2016
Mobile Mpesa Transfer
-1
833
-1
-13/11/2016
3/11/2016
Mobile Mpesa Transfer
-1
2033
-1
-14/11/2016
4/11/2016
ATM Withdrawal
5.04158E+15
3000
-1
-14/11/2016
4/11/2016
Mobile Internal Transfer
-1
0
3000
-14/11/2016
4/11/2016
Mobile Mpesa Transfer
-1
10033
-1
-17/11/2016
7/11/2016
Mobile Airtime Puchase
-1
150
-1
-17/11/2016
7/11/2016
Mobile Mpesa Transfer
-1
1183
-1
-17/11/2016
7/11/2016
Mobile Mpesa Transfer
-1
12283
-1
-17/11/2016
7/11/2016
Mobile Mpesa Transfer
-1
1498
-1
-17/11/2016
7/11/2016
Mobile Mpesa Transfer
-1
283
-1
-17/11/2016
7/11/2016
Mobile Mpesa Transfer
-1
333
-1
-17/11/2016
7/11/2016
Mobile Mpesa Transfer
-1
5033
-1
-17/11/2016
7/11/2016
Mobile Mpesa Transfer
-1
568
-1
-17/11/2016
7/11/2016
Mobile Mpesa Transfer
-1
733
-1
-17/11/2016
7/11/2016
Transfer from Mpesa
-1
0
20100
-18/11/2016
8/11/2016
Mobile Mpesa Transfer
-1
2033
-1
-18/11/2016
8/11/2016
Mobile Mpesa Transfer
-1
383
-1
-18/11/2016
8/11/2016
Mobile Mpesa Transfer
-1
6533
-1
-18/11/2016
8/11/2016
Mobile Mpesa Transfer
-1
938
-1
-18/11/2016
8/11/2016
Transfer from Mpesa
-1
0
14000
-19/11/2016
9/11/2016
Closing Balance
-1
-1
-1
-1

Answer 1

你的假设是空意味着没有任何迹象。仍然可以有像CR，LF或许多其他标志。

尝试以下方法：

if (string.IsNullOrWhiteSpace(fields[i])) // (fields[i].Length == 0)
{
    fields[i] = string.Format("{0}-1", Environment.NewLine);
}

Online check

Answer 2

尝试替换...

if (fields[i].Length == 0)
{
    fields[i] = "\n" + "-1";
}

有..。

if (String.IsNullOrEmpty(fields[i])) {
    fields[i] = "-1";
}