6098/Cowain.Bake.Common/Core/CSVHelper.cs

using CsvHelper;
using CsvHelper.Configuration;
using Microsoft.Win32;
using System.Collections.Generic;
using System.Data;
using System.Globalization;
using System.IO;

namespace Cowain.Bake.Common.Core
{
    public class CSVHelper
    {
        public static void WriteDataTableToCsv<T>(IEnumerable<T> list)
        {
            string filePath = GetFilePath();
            if (string.IsNullOrEmpty(filePath))
            {
                return;
            }
            using (var writer = new StreamWriter(filePath))
            using (var csv = new CsvWriter(writer, CultureInfo.InvariantCulture))
            {
                csv.WriteRecords(list);
            }
        }

        //列头是中文，所有字段都写入
        public static void WriteDataTableToCsv<T>(IEnumerable<T> list, List<string> nameCols)
        {
            string filePath = GetFilePath();
            if (string.IsNullOrEmpty(filePath))
            {
                return;
            }

            var config = new CsvConfiguration(CultureInfo.InvariantCulture)
            {
                // 设置列头编码为UTF8以支持中文
                Encoding = System.Text.Encoding.UTF8,
                    // 设置不写入列头
                HasHeaderRecord = false
            };

            using (var writer = new StreamWriter(filePath, false, System.Text.Encoding.UTF8))
            using (var csv = new CsvWriter(writer, config))
            {
                // 写入列头，使用中文列名
                foreach(var col in nameCols)
                {
                    csv.WriteField(col);
                }
                csv.NextRecord();

                // 写入数据行
                csv.WriteRecords(list);

            }
        }


        // 将List的特定列写入CSV文件的方法
        public static void WriteDataTableToCsv<T>(IEnumerable<T> list, IEnumerable<string> columnsToSave)
        {
            string filePath = GetFilePath();
            if (string.IsNullOrEmpty(filePath))
            {
                return;
            }
            var config = new CsvConfiguration(CultureInfo.InvariantCulture)
            {
                // 设置列头编码为UTF8以支持中文
                Encoding = System.Text.Encoding.UTF8,
                // 设置不写入列头
                HasHeaderRecord = false
            };

            using (var writer = new StreamWriter(filePath, false, System.Text.Encoding.UTF8))
            using (var csv = new CsvWriter(writer, config))
            {
                // 写入列头
                foreach (var columnName in columnsToSave)
                {
                    csv.WriteField(columnName);
                }
                csv.NextRecord();

                // 写入特定列数据
                foreach (var person in list)
                {
                    foreach (var columnName in columnsToSave)
                    {
                        var property = typeof(T).GetProperty(columnName);
                        if (property != null)
                        {
                            csv.WriteField(property.GetValue(person));
                        }
                    }
                    csv.NextRecord();
                }
            }
        }

        static string GetFilePath()
        {
            string filePath = "";
            //创建一个保存文件式的对话框
            SaveFileDialog saveFileDialog = new SaveFileDialog();
            //设置保存的文件的类型，注意过滤器的语法
            saveFileDialog.Filter = "CSV|*.csv";
            if (saveFileDialog.ShowDialog() == true)
            {
                filePath = saveFileDialog.FileName;
            }

            return filePath;
        }
        public static void WriteMap<T, TMap>(IEnumerable<T> list, string filePath) where TMap : ClassMap
        {
            var config = new CsvConfiguration(CultureInfo.InvariantCulture)
            {
                // 设置列头编码为UTF8以支持中文
                Delimiter = ",",
                HasHeaderRecord = true,
                Encoding = System.Text.Encoding.UTF8
            };


            if (File.Exists(filePath))
            {
                config.HasHeaderRecord = false;                // 获取字段描述作为列头
            }

            using (var writer = new StreamWriter(filePath, true, System.Text.Encoding.UTF8))
            using (var csv = new CsvWriter(writer, config))
            {
                // 注册自定义映射
                //csv.Context.RegisterClassMap<BatteryInfoMap>();
                csv.Context.RegisterClassMap<TMap>();
                // 写入记录
                csv.WriteRecords(list);
            }
        }
        public static void WriteMap<T, TMap>(IEnumerable<T> list ) where TMap : ClassMap //where TMap : ClassMap<T>   // 约束：必须是 ClassMap<T> 或其子类
        {
            string filePath = GetFilePath();
            if (string.IsNullOrEmpty(filePath))
            {
                return;
            }

            WriteMap<T, TMap>(list, filePath);
        }

        // 将List的特定列写入CSV文件的方法
        public static void WriteDataTableToCsv<T>(IEnumerable<T> list, IEnumerable<string> columnsToSave, IEnumerable<string> columnsToShow)
        {
            string filePath = GetFilePath();
            if (string.IsNullOrEmpty(filePath))
            {
                return;
            }

            var config = new CsvConfiguration(CultureInfo.InvariantCulture)
            {
                // 设置列头编码为UTF8以支持中文
                Encoding = System.Text.Encoding.UTF8,
                HasHeaderRecord = false
            };

            using (var writer = new StreamWriter(filePath, false, System.Text.Encoding.UTF8))
            using (var csv = new CsvWriter(writer, config))
            {
                // 写入列头
                foreach (var columnName in columnsToShow)
                {
                    csv.WriteField(columnName);
                }
                csv.NextRecord();

                // 写入特定列数据
                foreach (var person in list)
                {
                    foreach (var columnName in columnsToSave)
                    {
                        var property = typeof(T).GetProperty(columnName);
                        if (property != null)
                        {
                            csv.WriteField(property.GetValue(person));
                        }
                    }
                    csv.NextRecord();
                }
            }
        }

        // 将List的特定列写入CSV文件的方法
        public static void WriteDataTableToCsv<T>(IEnumerable<T> list, IEnumerable<string> columnsToSave, IEnumerable<string> columnsToShow, string filePath)
        {
            bool isFileExists = false;
            var config = new CsvConfiguration(CultureInfo.InvariantCulture)
            {
                // 设置列头编码为UTF8以支持中文
                Encoding = System.Text.Encoding.UTF8,
                HasHeaderRecord = false
            };

            if (File.Exists(filePath))
            {
                // 获取字段描述作为列头
                isFileExists = true;
            }

            using (var writer = new StreamWriter(filePath, true, System.Text.Encoding.UTF8))
            using (var csv = new CsvWriter(writer, config))
            {
                // 写入列头
                if (!isFileExists)
                {
                    foreach (var columnHeader in columnsToShow)
                    {
                        csv.WriteField(columnHeader);
                    }
                    csv.NextRecord();
                }

                // 写入特定列数据
                foreach (var person in list)
                {
                    foreach (var columnName in columnsToSave)
                    {
                        var property = typeof(T).GetProperty(columnName);
                        if (property != null)
                        {
                            csv.WriteField(property.GetValue(person));
                        }
                    }
                    csv.NextRecord();
                }
            }
        }

        // 将DataTable写入CSV文件的方法
        public static void WriteDataTableToCsv(DataTable dataTable)
        {
            string filePath = GetFilePath();
            if (string.IsNullOrEmpty(filePath))
            {
                return;
            }

            using (var writer = new StreamWriter(filePath))
            using (var csv = new CsvWriter(writer, CultureInfo.InvariantCulture))
            {
                // 写入表头
                foreach (DataColumn column in dataTable.Columns)
                {
                    csv.WriteField(column.ColumnName);
                }
                csv.NextRecord();

                // 写入数据行
                foreach (DataRow row in dataTable.Rows)
                {
                    for (var i = 0; i < dataTable.Columns.Count; i++)
                    {
                        csv.WriteField(row[i]);
                    }
                    csv.NextRecord();
                }
            }
        }
    }
}