详细代码如下：
1 public class CsvParsingHelper
2 {
3 /// <summary>
4 /// 将csv文件的数据转成datatable
5 /// </summary>
6 /// <param name="csvfilePath">csv文件路径</param>
7 /// <param name="firstIsRowHead">是否将第一行作为字段名</param>
8 /// <returns></returns>
9 public static DataTable CsvToDataTable(string csvfilePath, bool firstIsRowHead)
10 {
11 DataTable dtResult = null;
12 if (File.Exists(csvfilePath))
13 {
14 string csvstr = File.ReadAllText(csvfilePath, Encoding.Default);
15 if (!string.IsNullOrEmpty(csvstr))
16 {
17 dtResult = ToDataTable(csvstr, firstIsRowHead);
18 }
19 }
20 return dtResult;
21 }
22
23 /// <summary>
24 /// 将CSV数据转换为DataTable
25 /// </summary>
26 /// <param name="csv">包含以","分隔的CSV数据的字符串</param>
27 /// <param name="isRowHead">是否将第一行作为字段名</param>
28 /// <returns></returns>
29 private static DataTable ToDataTable(string csv, bool isRowHead)
30 {
31 DataTable dt = null;
32 if (!string.IsNullOrEmpty(csv))
33 {
34 dt = new DataTable();
35 string[] csvRows = csv.Split(new string[] { Environment.NewLine }, StringSplitOptions.RemoveEmptyEntries);
36 string[] csvColumns = null;
37 if (csvRows != null)
38 {
39 if (csvRows.Length > 0)
40 {
41 //第一行作为字段名,添加第一行记录并删除csvRows中的第一行数据
42 if (isRowHead)
43 {
44 csvColumns = FromCsvLine(csvRows[0]);
45 csvRows[0] = null;
46 for (int i = 0; i < csvColumns.Length; i++)
47 {
48 dt.Columns.Add(csvColumns[i]);
49 }
50 }
51
52 for (int i = 0; i < csvRows.Length; i++)
53 {
54 if (csvRows[i] != null)
55 {
56 csvColumns = FromCsvLine(csvRows[i]);
57 //检查列数是否足够,不足则补充
58 if (dt.Columns.Count < csvColumns.Length)
59 {
60 int columnCount = csvColumns.Length - dt.Columns.Count;
61 for (int c = 0; c < columnCount; c++)
62 {
63 dt.Columns.Add();
64 }
65 }
66 dt.Rows.Add(csvColumns);
67 }
68 }
69 }
70 }
71 }
72
73 return dt;
74 }
75 /// <summary>
76 /// 解析一行CSV数据
77 /// </summary>
78 /// <param name="csv">csv数据行</param>
79 /// <returns></returns>
80 public static string[] FromCsvLine(string csv)
81 {
82 List<string> csvLiAsc = new List<string>();
83 List<string> csvLiDesc = new List<string>();
84
85 if (!string.IsNullOrEmpty(csv))
86 {
87 //顺序查找
88 int lastIndex = 0;
89 int quotCount = 0;
90 //剩余的字符串
91 string lstr = string.Empty;
92 for (int i = 0; i < csv.Length; i++)
93 {
94 if (csv[i] == ‘"‘)
95 {
96 quotCount++;
97 }
98 else if (csv[i] == ‘,‘ && quotCount % 2 == 0)
99 {
100 csvLiAsc.Add(ReplaceQuote(csv.Substring(lastIndex, i - lastIndex)));
101 lastIndex = i + 1;
102 }
103 if (i == csv.Length - 1 && lastIndex < csv.Length)
104 {
105 lstr = csv.Substring(lastIndex, i - lastIndex + 1);
106 }
107 }
108 if (!string.IsNullOrEmpty(lstr))
109 {
110 //倒序查找
111 lastIndex = 0;
112 quotCount = 0;
113 string revStr = Reverse(lstr);
114 for (int i = 0; i < revStr.Length; i++)
115 {
116 if (revStr[i] == ‘"‘)
117 {
118 quotCount++;
119 }
120 else if (revStr[i] == ‘,‘ && quotCount % 2 == 0)
121 {
122 csvLiDesc.Add(ReplaceQuote(Reverse(revStr.Substring(lastIndex, i - lastIndex))));
123 lastIndex = i + 1;
124 }
125 if (i == revStr.Length - 1 && lastIndex < revStr.Length)
126 {
127 csvLiDesc.Add(ReplaceQuote(Reverse(revStr.Substring(lastIndex, i - lastIndex + 1))));
128 lastIndex = i + 1;
129 }
130
131 }
132 string[] tmpStrs = csvLiDesc.ToArray();
133 Array.Reverse(tmpStrs);
134 csvLiAsc.AddRange(tmpStrs);
135 }
136 }
137
138 return csvLiAsc.ToArray();
139 }
140 /// <summary>
141 /// 反转字符串
142 /// </summary>
143 /// <param name="str"></param>
144 /// <returns></returns>
145 private static string Reverse(string str)
146 {
147 string revStr = string.Empty;
148 foreach (char chr in str)
149 {
150 revStr = chr.ToString() + revStr;
151 }
152 return revStr;
153 }
154 /// <summary>
155 /// 替换CSV中的双引号转义符为正常双引号,并去掉左右双引号
156 /// </summary>
157 /// <param name="csvValue">csv格式的数据</param>
158 /// <returns></returns>
159 private static string ReplaceQuote(string csvValue)
160 {
161 string rtnStr = csvValue;
162 if (!string.IsNullOrEmpty(csvValue))
163 {
164 //首尾都是"
165 Match m = Regex.Match(csvValue, "^\"(.*?)\"$");
166 if (m.Success)
167 {
168 rtnStr = m.Result("${1}").Replace("\"\"", "\"");
169 }
170 else
171 {
172 rtnStr = rtnStr.Replace("\"\"", "\"");
173 }
174 }
175 return rtnStr;
176
177 }
178 }
CSV文件解析到DataTable,布布扣,bubuko.com
时间： 2024-12-25 22:06:53