如何在C＃中使用.IndexOf和.Substring从文本获取值？

Question

I need to make a summation for several values out from string variable,

Here is my variable:

string strBillHeader =  "Invoice Details
INVOICE_DATE,INVOICE_DESCRIPTION,VALUE,FROM_DATE,TO_DATE
01/11/2014,New Corpbundle 7,7,01/11/2014,30/11/2014
01/11/2014,New Corpbundle 7,-7,01/11/2014,30/11/2014
01/11/2014,New Corpbundle 7,7,01/11/2014,30/11/2014
01/11/2014,Missed Call ALERT with Offer,2,01/11/2014,30/11/2014"

I need to get out the VALUES which are (7,-7,7,2) in this case? and to get 9 as a result.

I tried to do it this way:

             for (int x = 4; x <= countCommas - 3; x += 4)
            {
int firstCommaIndex = strBillHeader.IndexOf(',', strBillHeader.IndexOf(',') + x);
                    int secondCommaIndex = strBillHeader.IndexOf(',', strBillHeader.IndexOf(',') + (x + 1));
                    string y = strBillHeader.Substring(firstCommaIndex + 1, 1);
                    chargeAmount = Convert.ToInt32(y);
                    //chargeAmount = Int32.Parse(strBillHeader.Substring(firstCommaIndex, secondCommaIndex - firstCommaIndex));
                    TotalChargeAmount += ChargeAmount;

                //string AstrBillHeader = strBillHeader.Split(',')[0];

            }

but it did not work since I keep getting 'V' in the y variable.

Any help will be appreciated

Answer 1

If those commas and newlines are always there, this should work:

var lines = strBillHeader.Split(Environment.NewLine).Skip(2);
int total = lines.Split(',').Sum(line => Convert.ToInt32(line[2]));

So, you split the invoice into lines and discard the first 2 (" Invoice Details " and " INVOICE_DATE,INVOICE_DESCRIPTION,VALUE,FROM_DATE,TO_DATE "). Then you split each line on the commas, and take the third value - the first is a date, the second is the " New Corpbundle 7 " part, the third is your value. You parse that value as an int , and sum the whole lot.

You may find you need to filter out the lines properly, rather than just assuming you can skip the first two and use the rest, but this should get you started.