使用 C# 将 csv 文件转换为 json
本文关键字:转换 json 文件 csv 使用 | 更新日期: 2023-09-27 18:36:01
我想知道是否有人编写了一个实用程序来使用 C# 将 CSV 文件转换为 Json。从之前关于堆栈溢出的问题中,我知道这个不错的实用程序 - https://github.com/cparker15/csv-to-json,目前我计划参考它,但现有的 C# 实现将非常有帮助!谢谢!
如果你可以使用System.Web.Extensions
,这样的事情可以工作:
var csv = new List<string[]>(); // or, List<YourClass>
var lines = System.IO.File.ReadAllLines(@"C:'file.txt");
foreach (string line in lines)
csv.Add(line.Split(',')); // or, populate YourClass
string json = new
System.Web.Script.Serialization.JavaScriptSerializer().Serialize(csv);
您可能对 csv 文件有更复杂的解析要求,并且您可能有一个封装一行数据的类,但关键是一旦您拥有一组行,您就可以使用一行代码序列化为 JSON。
Cinchoo ETL - 一个开源库,只需几行代码即可轻松将CSV转换为JSON。
对于示例 CSV:
Id, Name, City
1, Tom, NY
2, Mark, NJ
3, Lou, FL
4, Smith, PA
5, Raj, DC
示例代码,
string csv = @"Id, Name, City
1, Tom, NY
2, Mark, NJ
3, Lou, FL
4, Smith, PA
5, Raj, DC
";
StringBuilder sb = new StringBuilder();
using (var p = ChoCSVReader.LoadText(csv)
.WithFirstLineHeader()
)
{
using (var w = new ChoJSONWriter(sb))
w.Write(p);
}
Console.WriteLine(sb.ToString());
输出 JSON:
[
{
"Id": "1",
"Name": "Tom",
"City": "NY"
},
{
"Id": "2",
"Name": "Mark",
"City": "NJ"
},
{
"Id": "3",
"Name": "Lou",
"City": "FL"
},
{
"Id": "4",
"Name": "Smith",
"City": "PA"
},
{
"Id": "5",
"Name": "Raj",
"City": "DC"
}
]
样品小提琴:https://dotnetfiddle.net/pclnsT
查看代码项目文章以获取更多帮助。
更新:如果您的 CSV 文件有重复的列名称或没有名称,请使用以下步骤生成 JSON 文件
string csv = @"Id, Name,
1, Tom, NY
2, Mark, NJ
3, Lou, FL
4, Smith, PA
5, Raj, DC
";
StringBuilder sb = new StringBuilder();
using (var p = ChoCSVReader.LoadText(csv)
.WithField("Id", position: 1)
.WithField("Name", position: 2)
.WithField("City", position: 3)
.WithFirstLineHeader(true)
)
{
using (var w = new ChoJSONWriter(sb))
w.Write(p);
}
Console.WriteLine(sb.ToString());
样品小提琴:https://dotnetfiddle.net/pP5Du6
免责声明:我是这个库的作者。
我使用字典并使用Newtonsoft返回json
public string ConvertCsvFileToJsonObject(string path)
{
var csv = new List<string[]>();
var lines = File.ReadAllLines(path);
foreach (string line in lines)
csv.Add(line.Split(','));
var properties = lines[0].Split(',');
var listObjResult = new List<Dictionary<string, string>>();
for (int i = 1; i < lines.Length; i++)
{
var objResult = new Dictionary<string, string>();
for (int j = 0; j < properties.Length; j++)
objResult.Add(properties[j], csv[i][j]);
listObjResult.Add(objResult);
}
return JsonConvert.SerializeObject(listObjResult);
}
Install Nuget package NewtonSoft.Json
Add reference dll Microsoft.VisualBasic
using System.Linq;
using Newtonsoft.Json;
using Microsoft.VisualBasic.FileIO;
using System.IO;
using System;
using System.Collections.Generic;
using System.Globalization;
namespace Project
{
public static class Program
{
public static void Main(string[] args)
{
string CSVpath = @"D:'New Folder'information.csv";
string analyticsData = ReadFile(CSVpath);
}
private static string ReadFile(string filePath)
{
string payload = "";
try
{
if (!string.IsNullOrWhiteSpace(filePath) && File.Exists(filePath) && Path.GetExtension(filePath).Equals(".csv", StringComparison.InvariantCultureIgnoreCase))
{
string[] lines = File.ReadAllLines(filePath);
if (lines != null && lines.Length > 1)
{
var headers = GetHeaders(lines.First());
payload = GetPayload(headers, lines.Skip(1));
}
}
}
catch (Exception exp)
{
}
return payload;
}
private static IEnumerable<string> GetHeaders(string data)
{
IEnumerable<string> headers = null;
if (!string.IsNullOrWhiteSpace(data) && data.Contains(','))
{
headers = GetFields(data).Select(x => x.Replace(" ", ""));
}
return headers;
}
private static string GetPayload(IEnumerable<string> headers, IEnumerable<string> fields)
{
string jsonObject = "";
try
{
var dictionaryList = fields.Select(x => GetField(headers, x));
jsonObject = JsonConvert.SerializeObject(dictionaryList);
}
catch (Exception ex)
{
}
return jsonObject;
}
private static Dictionary<string, string> GetField(IEnumerable<string> headers, string fields)
{
Dictionary<string, string> dictionary = null;
if (!string.IsNullOrWhiteSpace(fields))
{
var columns = GetFields(fields);
if (columns != null && headers != null && columns.Count() == headers.Count())
{
dictionary = headers.Zip(columns, (x, y) => new { x, y }).ToDictionary(item => item.x, item => item.y);
}
}
return dictionary;
}
public static IEnumerable<string> GetFields(string line)
{
IEnumerable<string> fields = null;
using (TextReader reader = new StringReader(line))
{
using (TextFieldParser parser = new TextFieldParser(reader))
{
parser.TextFieldType = FieldType.Delimited; parser.SetDelimiters(","); fields = parser.ReadFields();
}
}
return fields;
}
}
}
仅依赖于Newtonsoft.Json,这是一个给定CSV行数组的辅助方法,第一个是标头。
public static IEnumerable<JObject> CsvToJson(IEnumerable<string> csvLines)
{
var csvLinesList = csvLines.ToList();
var header = csvLinesList[0].Split(',');
for (int i = 1; i < csvLinesList.Count; i++)
{
var thisLineSplit = csvLinesList[i].Split(',');
var pairedWithHeader = header.Zip(thisLineSplit, (h, v) => new KeyValuePair<string, string>(h, v));
yield return new JObject(pairedWithHeader.Select(j => new JProperty(j.Key, j.Value)));
}
}
我使用ChoETL:
using ChoETL;
using System.IO;
public class FromCSVtoJSON
{
public FromCSVtoJSON()
{
}
public void convertFile(string inputFile, string outputFile)
{
using (var writer = new ChoJSONWriter(outputFile))
{
using (var reader = new ChoCSVReader(inputFile).WithFirstLineHeader())
{
writer.Write(reader);
}
}
}
}
从同一个 SO 答案中,有一个指向这篇文章的链接。
CsvToJson 扩展方法
/// <summary>
/// Converts a CSV string to a Json array format.
/// </summary>
/// <remarks>First line in CSV must be a header with field name columns.</remarks>
/// <param name="value"></param>
/// <returns></returns>
public static string CsvToJson(this string value)
{
// Get lines.
if (value == null) return null;
string[] lines = value.Split(new string[] { Environment.NewLine }, StringSplitOptions.RemoveEmptyEntries);
if (lines.Length < 2) throw new InvalidDataException("Must have header line.");
// Get headers.
string[] headers = lines.First().SplitQuotedLine(new char[] { ',' }, false);
// Build JSON array.
StringBuilder sb = new StringBuilder();
sb.AppendLine("[");
for (int i = 1; i < lines.Length; i++)
{
string[] fields = lines[i].SplitQuotedLine(new char[] { ',', ' ' }, true, '"', false);
if (fields.Length != headers.Length) throw new InvalidDataException("Field count must match header count.");
var jsonElements = headers.Zip(fields, (header, field) => string.Format("{0}: {1}", header, field)).ToArray();
string jsonObject = "{" + string.Format("{0}", string.Join(",", jsonElements)) + "}";
if (i < lines.Length - 1)
jsonObject += ",";
sb.AppendLine(jsonObject);
}
sb.AppendLine("]");
return sb.ToString();
}
在上述扩展中调用的某些方法似乎存在问题(请参阅原始博客文章的评论),但它应该可以让您大部分时间到达那里。
编辑 这是关于拆分 CSV 行的另一个答案。您可以使用建议的正则表达式解决方案之一来创建自己的SplitQuotedLine
方法:
public static string SplitQuotedLine(this string value, char separator, bool quotes) {
// Use the "quotes" bool if you need to keep/strip the quotes or something...
var s = new StringBuilder();
var regex = new Regex("(?<=^|,)('"(?:[^'"]|'"'")*'"|[^,]*)");
foreach (Match m in regex.Matches(value)) {
s.Append(m.Value);
}
return s.ToString();
}
我没有测试上述内容,所以如果我犯了任何错误,请原谅我。
此外,Zip 似乎是一种 LINQ 扩展方法,因此可以解决这个问题。
的..它可以解析几个世纪以来的 9k CSV 记录。大声笑
class CSVTOJSON
{
public string ConvertToJSON()
{
string json = string.Empty;
string csv = string.Empty;
using (StreamReader reader = new StreamReader("data.csv"))
{
csv = reader.ReadToEnd();
}
string[] lines = csv.Split(new string[] { "'n" }, System.StringSplitOptions.None);
if (lines.Length > 1)
{
// parse headers
string[] headers = lines[0].Split(',');
StringBuilder sbjson = new StringBuilder();
sbjson.Clear();
sbjson.Append("[");
// parse data
for (int i = 1; i < lines.Length; i++)
{
if (string.IsNullOrWhiteSpace(lines[i])) continue;
if (string.IsNullOrEmpty(lines[i])) continue;
sbjson.Append("{");
string[] data = lines[i].Split(',');
for (int h = 0; h < headers.Length; h++)
{
sbjson.Append(
$"'"{headers[h]}'": '"{data[h]}'"" + (h < headers.Length - 1 ? "," : null)
);
}
sbjson.Append("}" + (i < lines.Length - 1 ? "," : null));
}
sbjson.Append("]");
json = sbjson.ToString();
}
return json;
}
}
但它有效。
控制台日志:
Converting CSV to JSON
CSV has 9486 data
Total duration converting CSV to JSON: 00:00:00.0775373
bc3tech 对解决方案的微小变化,即避免外部依赖(在 Newtonsoft.Json 上),而是使用 System.Text.Json(dotnet core 3+)
public static IEnumerable<string> CsvToJson(string fileName, char delim = '|')
{
var lines = File.ReadLines(fileName);
var hdr = new List<string>(lines.First().Trim().Split(delim));
foreach (var l in lines.Skip(1).Where(l => (l.Trim() != String.Empty)))
{
var val = l.Trim().Split(delim);
var ds = hdr.Zip(val, (k, v) => new { k, v }).ToDictionary(x => x.k, x => x.v);
yield return JsonSerializer.Serialize(ds);
}
}
我可以看到大多数人只是简单地假设解析CSV文件只是在每列之间拆分逗号分隔符,但以下格式仍然是有效的CSV
"aaa","bbb","ccc"
"z, z",yyy,xxx
Microsoft.VisualBasic.FileIO中隐藏了一个很好的类,可以正确处理CSV文件格式。我将其与 JSON.NET 想出的解决方案结合起来。
public static string? CsvToJson(string input, string delimiter)
{
using (TextFieldParser parser = new TextFieldParser(
new MemoryStream(Encoding.UTF8.GetBytes(input))))
{
parser.Delimiters = new string[] { delimiter };
string[]? headers = parser.ReadFields();
if (headers == null) return null;
string[]? row;
string comma = "";
var sb = new StringBuilder((int)(input.Length * 1.1));
sb.Append("[");
while ((row = parser.ReadFields()) != null)
{
var dict = new Dictionary<string, object>();
for (int i = 0; row != null && i < row.Length; i++)
dict[headers[i]] = row[i];
var obj = JsonConvert.SerializeObject(dict);
sb.Append(comma + obj);
comma = ",";
}
return sb.Append("]").ToString();
}
}
用法
var str = @"Header1,""Header,,2 "",Data3
1,444.00, ""Liang, Jerry""
0,""5,550"",Jerry
";
var json = CsvToJson(str, ",");
结果
[
{
"Header1": "1",
"Header,,2": "444.00",
"Data3": "Liang, Jerry"
},
{
"Header1": "0441",
"Header,,2": "5,550",
"Data3": "Jerry"
}
]
我寻找这个问题的答案,最后我使用字典解决了它
public static void CreateJsonFromCSV()
{
string path = "C:''Users''xx''xx''xx''xx''lang.csv";
string textFilePath = path;
const Int32 BufferSize = 128;
using (var fileStream = File.OpenRead(textFilePath))
using (var streamReader = new StreamReader(fileStream, Encoding.UTF8, true, BufferSize))
{
String line;
Dictionary<string, string> jsonRow = new Dictionary<string, string>();
while ((line = streamReader.ReadLine()) != null)
{
string[] parts = line.Split(',');
string key_ = parts[0];
string value = parts[1];
if (!jsonRow.Keys.Contains(key_))
{
jsonRow.Add(key_, value );
}
}
var json = new JavaScriptSerializer().Serialize(jsonRow);
string path_ = "C:''XX''XX''XX''XX''XX.csv";
File.WriteAllText(path_, json);
}
}
在解析大型 csv 文件之前,请确保在 web.config 中添加以下内容。
<system.web.extensions>
<scripting>
<webServices>
<jsonSerialization maxJsonLength="50000000"/>
</webServices>
</scripting>
</system.web.extensions>
试试这个:
StreamReader sr = new StreamReader(filePath);
while ((line = sr.ReadLine()) != null)
{
//Console.WriteLine(line);
string[] csv = line.Split(',');
var dictionary = new Dictionary<string, string>();
dictionary.Add("dispatching_base_number",csv[0]);
dictionary.Add("available_vehicles", csv[1]);
dictionary.Add("vehicles_in_trips", csv[2]);
dictionary.Add("Cancellations", csv[3]);
string jsonN = new System.Web.Script.Serialization.JavaScriptSerializer().Serialize(dictionary);
Console.WriteLine("Sending message: {0}",jsonN);
}
试试这个并将CSV
转换为JSON
对象:
public static List<object> CsvToJson( string body, string[] column ) {
if ( string.IsNullOrEmpty( body ) ) return null;
string[] rowSeparators = new string[] { "'r'n" };
string[] rows = body.Split( rowSeparators, StringSplitOptions.None );
body = null;
if ( rows == null || ( rows != null && rows.Length == 0 ) ) return null;
string[] cellSeparator = new string[] { "," };
List<object> data = new List<object>( );
int clen = column.Length;
rows.Select( row => {
if ( string.IsNullOrEmpty( row ) ) return row;
string[] cells = row.Trim( ).Split( cellSeparator, StringSplitOptions.None );
if ( cells == null ) return row;
if ( cells.Length < clen ) return row;
Dictionary<object, object> jrows = new Dictionary<object, object>( );
for ( int i = 0; i < clen; i++ ) {
jrows.Add( column[i], cells[i]?.Trim( ) );
}
data.Add( jrows );
return row;
} ).ToList( );
rowSeparators = null; rows = null;
cellSeparator = null;
return data;
}
var data = CsvToJson("csv_input_str", new string[]{ "column_map" })
string jsonStr = new JavaScriptSerializer { MaxJsonLength = int.MaxValue }.Serialize( data );
首先,将 csv 文件加载到数据表中,并将其序列化为 Json 文档。它使用OLEDB提供程序,可以明智地解析csv,
由 Jim Scott 提供,https://stackoverflow.com/a/1050278/6928056
由K_B提供,https://stackoverflow.com/a/2979938/6928056
using System.Data;
using System.Data.OleDb;
using System.Globalization;
using System.IO;
using Newtonsoft.Json;
static string ConvertCsvToJson(string path, bool isFirstRowHeader)
{
string header = isFirstRowHeader ? "Yes" : "No";
string pathOnly = Path.GetDirectoryName(path);
string fileName = Path.GetFileName(path);
string sql = @"SELECT * FROM [" + fileName + "]";
using(OleDbConnection connection = new OleDbConnection(
@"Provider=Microsoft.Jet.OLEDB.4.0;Data Source=" + pathOnly +
";Extended Properties='"Text;HDR=" + header + "'""))
using(OleDbCommand command = new OleDbCommand(sql, connection))
using(OleDbDataAdapter adapter = new OleDbDataAdapter(command))
{
var dataTable = new DataTable();
dataTable.Locale = CultureInfo.CurrentCulture;
adapter.Fill(dataTable);
return JsonConvert.SerializeObject(dataTable, Formatting.Indented);
}
}
将平面 csv 文件转换为简单 JSON 格式对象的集合的简单方法。适用于标题行位于第一行的文件。这种方法的一部分是在SO的其他地方找到的。添加对 Microsoft.VisualBasic 的引用。
using Microsoft.VisualBasic.FileIO;
public static StringBuilder ReadCsv()
{
var path = @"X:'...'input.csv";
using (TextFieldParser csvParser = new TextFieldParser(path))
{
csvParser.CommentTokens = new string[] { "#" };
//Remember to use your own separator
csvParser.SetDelimiters(new string[] { ";" });
csvParser.HasFieldsEnclosedInQuotes = false;
StringBuilder json = new StringBuilder();
string[] colNames = new string[0];
string[] fields = new string[0];
json.Append("[");
int counter = 0;
while (!csvParser.EndOfData)
{
if (counter == 0)
{
//Read properies' names
colNames = csvParser.ReadFields();
counter++;
Console.WriteLine($"{colNames.Length} columns detected!");
}
else
{
// Read current line fields, pointer moves to the next line.
// Read the properties' values
fields = csvParser.ReadFields();
json.Append("{");
for (int i = 0; i < colNames.Length; i++)
{
json.Append($"'"{colNames[i]}'":{TryParse(fields[i])}");
if (i != colNames.Length - 1)
{
json.Append(",");
}
}
json.Append("},");
Console.WriteLine($"Writing record nr.: {counter}");
counter++;
}
}
json.Length--; //Remove trailing comma
json.Append("]");
return json;
}
}
string TryParse(string s)
{
if (string.IsNullOrEmpty(s)) return "null";
//Remember to set your decimal character here!
if (s.Contains('.'))
{
double dResult;
//This works on my computer, could be different on your machine
if (double.TryParse(s, NumberStyles.AllowDecimalPoint,
CultureInfo.InvariantCulture, out dResult))
return dResult.ToString(CultureInfo.InvariantCulture);
}
else
{
int intResult;
if (int.TryParse(s, out intResult))
return intResult.ToString(CultureInfo.InvariantCulture);
}
return "'"" + s + "'"";
}
<小时 />这应该会给你一个简单的 json 对象列表。
如果您正在寻找仅限 C# 的解决方案,这可能适合您。我最近面临同样的问题,并创建了这种方法来克服。
public static string ConvertToJsonStructure(string csvDataAsString, char delimiter = ',', bool hasHeaders = true)
{
var output = string.Empty;
if (string.IsNullOrEmpty(csvDataAsString))
return "{}";
var rows = csvDataAsString.Split(new string[] { Environment.NewLine }, StringSplitOptions.None);
var headers = hasHeaders ? rows[0].Split(delimiter) : null;
var colCount = headers?.Length;
var jsonStart = "{";
var jsonEnd = "}";
if (rows.Length > (1 + (hasHeaders ? 1 : 0)))
{
jsonStart = "[";
jsonEnd = "]";
}
output = output + jsonStart;
int startIndex = hasHeaders ? 1 : 0;
for (int i = startIndex; i < rows.Length; i++)
{
var cols = rows[i].Split(delimiter);
if (colCount == null)
colCount = cols.Length;
var tempJson = "{";
for (int j = 0; j < colCount.Value; j++)
{
if (hasHeaders)
tempJson = tempJson + $"'"{headers[j]}'":";
var isNumber = Regex.IsMatch(cols[j], @"^'d + $");
var val = isNumber ? cols[j] : $"'"{cols[j]}'"";
tempJson = tempJson + val;
if (j < colCount.Value - 1)
tempJson = tempJson + ",";
}
tempJson = tempJson + "}";
if (i < rows.Length - 1)
tempJson = tempJson + ",";
output = output + tempJson;
}
output = output + jsonEnd;
return output;
}
}
您需要将内容作为字符串传递给此方法,您可以执行类似操作来读取您的csv
var csvAsString = File.ReadAllText("TestCsv.csv");
var result = CsvToJson.ConvertToJsonStructure(csvAsString);
所有这些答案中看到的无数原因,请站在巨人的肩膀上并使用 Csv 解析 nuget 包提取数据,然后使用内置序列化程序将其序列化为 JSON。根本没有理由手掷这个。