使用csv檔案存盤資料比excel更加輕量級，支持的場景更加豐富，可以完全自定義，不受excel約束， 但是對csv檔案的決議和讀取，網上的資料又不是很多，這里通過拿來linq to csv的原始碼并在其基礎上進行擴展，以支持遇到的一些問題，
主要擴展的功能點：
1-支持設定標題行 （原始碼僅支持設定首行是否為標題行）
2-支持設定標題跟資料的映射關系 （原始碼通過下標設定資料關系，這一點如果標題行過多時，數位置是很頭疼的，尤其是在多列中再插入一列...而通過標題跟資料映射就很簡單了，自動尋找下標）
2-自動列印錯誤行資料并忽略錯誤行資料（這點和原始碼差不多）
3-定義資料格式（和原始碼一致）
我的前兩篇關于csv的幫助文章也可以參考下：
C#使用Linq to csv讀取.csv檔案資料
C#使用Linq to csv讀取.csv檔案資料2_處理含有非列名資料的方法（說明資訊等）
改造完整代碼如下：
1-Csv檔案類特性標記：
/// <summary> /// Csv檔案類特性標記 /// </summary> [System.AttributeUsage(System.AttributeTargets.Field | System.AttributeTargets.Property, AllowMultiple = false)] public class CsvColumnAttribute : System.Attribute { /// <summary> /// 標題 /// </summary> public string Title { get; set; } /// <summary> /// 字符輸出格式（數字和日期型別需要） /// </summary> public string OutputFormat { get; set; } public CsvColumnAttribute() { Title = ""; OutputFormat = ""; } public CsvColumnAttribute(string title, string outputFormat) { Title = title; OutputFormat = outputFormat; } }CsvColumnAttribute
2-CsvFileDescription：
public class CsvFileDescription { public CsvFileDescription() : this(1) { } public CsvFileDescription(int titleRawIndex) : this(',', titleRawIndex, Encoding.UTF8) { } public CsvFileDescription(char separatorChar, int titleRawIndex, Encoding encoding) { this.SeparatorChar = separatorChar; this.TitleRawIndex = titleRawIndex; this.Encoding = encoding; } /// <summary> /// CSV檔案字符編碼 /// </summary> public Encoding Encoding { get; set; } /// <summary> /// 分隔符（默認為（,）,也可以是其他分隔符如(\t)） /// </summary> public char SeparatorChar { get; set; } /// <summary> /// 標題所在行位置（默認為1，沒有標題填0） /// </summary> public int TitleRawIndex { get; set; } }CsvFileDescription
3-欄位映射類：
/// <summary> /// 欄位映射類 /// </summary> public class FieldMapper { /// <summary> /// 屬性資訊 /// </summary> public PropertyInfo PropertyInfo { get; set; } /// <summary> /// 標題 /// </summary> public string CSVTitle { get; set; } /// <summary> /// 標題下標位置 /// </summary> public int CSVTitleIndex { get; set; } /// <summary> /// 字符輸出格式（數字和日期型別需要） /// </summary> public string OutputFormat { get; set; } public static List<FieldMapper> GetModelFieldMapper<T>() { List<FieldMapper> fieldMapperList = new List<FieldMapper>(100); List<PropertyInfo> tPropertyInfoList = typeof(T).GetProperties().ToList(); CsvColumnAttribute csvColumnAttribute = null; int beginTitleIndex = 1; foreach (var tPropertyInfo in tPropertyInfoList) { csvColumnAttribute = (CsvColumnAttribute)tPropertyInfo.GetCustomAttribute(typeof(CsvColumnAttribute)); if (csvColumnAttribute != null) { fieldMapperList.Add(new FieldMapper { PropertyInfo = tPropertyInfo, CSVTitle = csvColumnAttribute.Title, CSVTitleIndex = beginTitleIndex, OutputFormat = csvColumnAttribute.OutputFormat }); beginTitleIndex++; } } return fieldMapperList; } }FieldMapper
4-CsvHelper幫助類：
public class CsvHelper { /// <summary> /// 日志 /// </summary> private ILogger _Logger { get; set; } public CsvHelper(ILogger<CsvHelper> logger) { this._Logger = logger; } public List<T> Read<T>(string filePath, CsvFileDescription fileDescription) where T : class, new() { List<T> tList = new List<T>(50 * 10000); T t = null; int currentRawIndex = 1; if (File.Exists(filePath)) { using (StreamReader streamReader = new StreamReader(filePath, fileDescription.Encoding)) { Dictionary<int, FieldMapper> fieldMapperDic = FieldMapper.GetModelFieldMapper<T>().ToDictionary(m => m.CSVTitleIndex); string rawValue = https://www.cnblogs.com/lxhbky/archive/2020/09/22/null; string[] rawValueArray = null; PropertyInfo propertyInfo = null; string propertyValue = https://www.cnblogs.com/lxhbky/archive/2020/09/22/null; bool rawReadEnd = false; bool isExistSplitChart = false; do { rawValue = streamReader.ReadLine(); //標題行 if (currentRawIndex > fileDescription.TitleRawIndex) { if (!string.IsNullOrEmpty(rawValue)) { //替換字串含有分隔符為{分隔符}，最后再替換回來 if (rawValue.Contains("\"")) { isExistSplitChart = true; int yhBeginIndex = 0; int yhEndIndex = 0; string yhText = null; do { yhBeginIndex = StringHelper.GetIndexOfStr(rawValue, "\"", 1); yhEndIndex = StringHelper.GetIndexOfStr(rawValue, "\"", 2); yhText = rawValue.Substring(yhBeginIndex, (yhEndIndex - yhBeginIndex + 1)); string newYHText = yhText.Replace("\"", "").Replace(fileDescription.SeparatorChar.ToString(), "{分隔符}"); rawValue = rawValue.Replace(yhText, newYHText); } while (rawValue.Contains("\"")); } rawValueArray = rawValue.Split(fileDescription.SeparatorChar); t = new T(); bool isExistException = false; foreach (var fieldMapper in fieldMapperDic) { try { propertyInfo = fieldMapper.Value.PropertyInfo; propertyValue = rawValueArray[fieldMapper.Key - 1]; if (!string.IsNullOrEmpty(propertyValue)) { if (isExistSplitChart && propertyValue.Contains("{分隔符}")) { propertyValue = propertyValue.Replace("{分隔符}", fileDescription.SeparatorChar.ToString()); } TypeHelper.SetPropertyValue(t, propertyInfo.Name, propertyValue); } } catch (Exception e) { isExistException = true; this._Logger.LogWarning(e, $"第{currentRawIndex}行資料{propertyValue}轉換屬性{propertyInfo.Name}-{propertyInfo.PropertyType.Name}失敗！檔案路徑：{filePath}"); break; } } if (isExistException == false) { tList.Add(t); } } else { rawReadEnd = true; } } currentRawIndex++; } while (rawReadEnd == false); } } return tList; } public void WriteFile<T>(string path, List<T> tList, CsvFileDescription fileDescription) where T : class, new() { if (!string.IsNullOrEmpty(path)) { string fileDirectoryPath = null; if (path.Contains("\\")) { fileDirectoryPath = path.Substring(0, path.LastIndexOf('\\')); } else { fileDirectoryPath = path.Substring(0, path.LastIndexOf('/')); } if (!Directory.Exists(fileDirectoryPath)) { Directory.CreateDirectory(fileDirectoryPath); } int dataCount = tList.Count; Dictionary<int, FieldMapper> fieldMapperDic = FieldMapper.GetModelFieldMapper<T>().ToDictionary(m => m.CSVTitleIndex); int titleCount = fieldMapperDic.Keys.Max(); string[] rawValueArray = new string[titleCount]; StringBuilder rawValueBuilder = new StringBuilder(); string rawValue = https://www.cnblogs.com/lxhbky/archive/2020/09/22/null; T t = null; PropertyInfo propertyInfo = null; int currentRawIndex = 1; int tIndex = 0; using (StreamWriter streamWriter = new StreamWriter(path, false, fileDescription.Encoding)) { do { try { rawValue = ""; #if DEBUG if (currentRawIndex % 10000 == 0) { this._Logger.LogInformation($"已寫入檔案：{path}，資料量：{currentRawIndex}"); } #endif if (currentRawIndex >= fileDescription.TitleRawIndex) { //清空陣列資料 for (int i = 0; i < titleCount; i++) { rawValueArray[i] = ""; } if (currentRawIndex > fileDescription.TitleRawIndex) { t = tList[tIndex]; tIndex++; } foreach (var fieldMapperItem in fieldMapperDic) { //寫入標題行 if (currentRawIndex == fileDescription.TitleRawIndex) { rawValueArray[fieldMapperItem.Key - 1] = fieldMapperItem.Value.CSVTitle; } //真正的資料從標題行下一行開始寫 else { propertyInfo = fieldMapperItem.Value.PropertyInfo; object propertyValue =https://www.cnblogs.com/lxhbky/archive/2020/09/22/ propertyInfo.GetValue(t); string formatValue = https://www.cnblogs.com/lxhbky/archive/2020/09/22/null; if (propertyValue != null) { if (propertyInfo.PropertyType is IFormattable && !string.IsNullOrEmpty(fieldMapperItem.Value.OutputFormat)) { formatValue = ((IFormattable)propertyValue).ToString(fieldMapperItem.Value.OutputFormat, null); } else { formatValue = propertyValue.ToString(); } //如果屬性值含有分隔符，則使用雙引號包裹 if (formatValue.Contains(fileDescription.SeparatorChar.ToString())) { formatValue = $"\"{formatValue}\""; } rawValueArray[fieldMapperItem.Key - 1] = formatValue; } } } rawValue = string.Join(fileDescription.SeparatorChar, rawValueArray); } rawValueBuilder.Append(rawValue + "\r\n"); } catch (Exception e) { this._Logger.LogWarning(e, $"(例外)Excel第{currentRawIndex}行，資料串列第{tIndex + 1}個資料寫入失敗！rawValue：{rawValue}"); throw; } currentRawIndex++; } while (tIndex < dataCount); streamWriter.Write(rawValueBuilder.ToString()); streamWriter.Close(); streamWriter.Dispose(); } } } }CsvHelper
示例：
使用類：
/// <summary> /// CSV檔案資料 /// </summary> public class CSVModel { /// <summary> /// 公司賬號 /// </summary> [CsvColumn(Title = "Company Account")] public string CompanyAccount { get; set; } /// <summary> /// 支付賬號商家代碼 /// </summary> [CsvColumn(Title = "Merchant Account")] public string MerchantAccount { get; set; } }
CsvFileDescription csvFileDescription = new CsvFileDescription(3); List<CSVModel> item1List = new CsvHelper().Read<OrderTransaction.Adyen.CSVModel>("/test.csv", csvFileDescription);
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標籤：.NET技术