Parse CSV line

 

/// <summary>
        ///ParseLine 的测试
        ///</summary>
        [TestMethod()]
        public void ParseLineTest()
        {
            Core target = new Core(); // TODO: 初始化为适当的值
            string src = "1,ab ,c,\"\"\",e,f,g,\"\",\",smile,go,\"\"\",e1,f,g,\"\",\"";
            List<string> expected =new List<string>();
                //expected.Add("1,ab ,c,") ;
                //expected.Add("\",e,f,g,\",");
                //expected.Add(",smile,go");

            expected.Add("1") ;
            expected.Add("ab ");
            expected.Add("c");
            expected.Add("\",e,f,g,\",");
            expected.Add("smile");
            expected.Add("go");
            expected.Add("\",e1,f,g,\",");
            //expected.Add("\",e,f,g,\",");
            //expected.Add(",smile,go");
            List<string> actual;
            actual = target.ParseLine(src);
            for(int i=0;i<expected.Count;i++)
            {
               Assert.AreEqual(expected[i], actual[i]);

            }
        }

 

 

 

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.IO;
using System.Text.RegularExpressions;

namespace CSVParser
{
    public class Core
    {

        public List<string> ParseLine(string src)
        {
            List<String> r = new List<string>();
            bool inBlock = false;
            StringBuilder sb = new StringBuilder();
            string rowBlock = string.Empty;
            using (StringReader sr = new StringReader(src))
            {

                int val = sr.Read();
                char nextChar = (char)sr.Peek();

                while (val > 0)
                {
                    char c = (char)val;
                    int nextVal = sr.Peek();
                    nextChar = (char)nextVal;

                    if (!inBlock)
                    {
                        if (c == '\"')
                        {
                            string[] list = sb.ToString().Split(new char[]{','},StringSplitOptions.RemoveEmptyEntries);
                            foreach (string cell in list)
                            {
                                r.Add(cell);
                            }

                            sb.Length = 0;
                            inBlock = true;
                        }
                        else
                        {
                            sb.Append(c);
                        }
                    }
                    else
                    {
                        if (c == '\"' && nextChar == '\"')
                        {
                            c = (char)sr.Read();
                            sb.Append(c);
                        }
                        else if (c == '\"' &&
                            (nextChar == ','
                            ||nextVal==-1
                            )                           
                            )
                        {
                            r.Add(sb.ToString());

                            sb.Length = 0;
                            inBlock = false;

                        }
                        else
                        {
                            sb.Append(c);
                        }
                    }

                    val = sr.Read();
                }

                if (sb.Length > 0)
                {
                    string[] list = sb.ToString().Split(new char[] { ',' }, StringSplitOptions.RemoveEmptyEntries);
                    foreach (string cell in list)
                    {
                        r.Add(cell);
                    }
                }

            }
            return r;
        }
    }
}