开源项目 10 CSV

using Newtonsoft.Json;
using System;
using System.Collections.Generic;
using System.Data;
using System.IO;
using System.Linq;
using System.Reflection;
using System.Text;
using System.Threading.Tasks;

namespace ConsoleApp2.test1
{
    public class Class10
    {
        public void test1()
        {
            var dt = CSVFileHelper.OpenCSV(@"1.csv");

            dt.Columns["联系人姓名"].ColumnName = "Name";
            dt.Columns["备注"].ColumnName = "Remark";

            var list = dt.DataTableToEntities<Crm_Cm_ContactInfo2>();

            Console.WriteLine(dt.Rows.Count);
            Console.WriteLine(JsonConvert.SerializeObject(list));
        }
    }

    public class Crm_Cm_ContactInfo2
    {
        public string Name { get; set; }
        public string Remark { get; set; }
    }

    public class CSVFileHelper
    {
        /// <summary>
        /// 将DataTable中数据写入到CSV文件中
        /// </summary>
        /// <param name="dt">提供保存数据的DataTable</param>
        /// <param name="fileName">CSV的文件路径</param>
        public static void SaveCSV(DataTable dt, string fullPath)
        {
            FileInfo fi = new FileInfo(fullPath);
            if (!fi.Directory.Exists)
            {
                fi.Directory.Create();
            }
            FileStream fs = new FileStream(fullPath, System.IO.FileMode.Create, System.IO.FileAccess.Write);
            //StreamWriter sw = new StreamWriter(fs, System.Text.Encoding.Default);
            StreamWriter sw = new StreamWriter(fs, System.Text.Encoding.UTF8);
            string data = "";
            //写出列名称
            for (int i = ; i < dt.Columns.Count; i++)
            {
                data += dt.Columns[i].ColumnName.ToString();
                if (i < dt.Columns.Count - )
                {
                    data += ",";
                }
            }
            sw.WriteLine(data);
            //写出各行数据
            for (int i = ; i < dt.Rows.Count; i++)
            {
                data = "";
                for (int j = ; j < dt.Columns.Count; j++)
                {
                    string str = dt.Rows[i][j].ToString();
                    str = str.Replace("\"", "\"\"");//替换英文冒号 英文冒号需要换成两个冒号
                    if (str.Contains(',') || str.Contains('"')
                        || str.Contains('\r') || str.Contains('\n')) //含逗号 冒号 换行符的需要放到引号中
                    {
                        str = string.Format("\"{0}\"", str);
                    }

                    data += str;
                    if (j < dt.Columns.Count - )
                    {
                        data += ",";
                    }
                }
                sw.WriteLine(data);
            }
            sw.Close();
            fs.Close();
        }

        /// <summary>
        /// 将CSV文件的数据读取到DataTable中
        /// </summary>
        /// <param name="fileName">CSV文件路径</param>
        /// <returns>返回读取了CSV数据的DataTable</returns>
        public static DataTable OpenCSV(string filePath)
        {
            Encoding encoding = Encoding.Default; //Encoding.ASCII;//Common.GetType(filePath)
            DataTable dt = new DataTable();
            FileStream fs = new FileStream(filePath, System.IO.FileMode.Open, System.IO.FileAccess.Read);

            //StreamReader sr = new StreamReader(fs, Encoding.UTF8);
            StreamReader sr = new StreamReader(fs, encoding);
            //string fileContent = sr.ReadToEnd();
            //encoding = sr.CurrentEncoding;
            //记录每次读取的一行记录
            string strLine = "";
            //记录每行记录中的各字段内容
            string[] aryLine = null;
            string[] tableHead = null;
            //标示列数
            int columnCount = ;
            //标示是否是读取的第一行
            bool IsFirst = true;
            //逐行读取CSV中的数据
            while ((strLine = sr.ReadLine()) != null)
            {
                //strLine = Common.ConvertStringUTF8(strLine, encoding);
                //strLine = Common.ConvertStringUTF8(strLine);

                if (IsFirst == true)
                {
                    tableHead = strLine.Split(',');
                    IsFirst = false;
                    columnCount = tableHead.Length;
                    //创建列
                    for (int i = ; i < columnCount; i++)
                    {
                        DataColumn dc = new DataColumn(tableHead[i]);
                        dt.Columns.Add(dc);
                    }
                }
                else
                {
                    aryLine = strLine.Split(',');
                    DataRow dr = dt.NewRow();
                    for (int j = ; j < columnCount; j++)
                    {
                        dr[j] = aryLine[j];
                    }
                    dt.Rows.Add(dr);
                }
            }
            if (aryLine != null && aryLine.Length > )
            {
                dt.DefaultView.Sort = tableHead[] + " " + "asc";
            }

            sr.Close();
            fs.Close();
            return dt;
        }
    }

    /// <summary>
    /// 反射类
    /// </summary>
    public static class MyReflection
    {
        /// <summary>
        /// DataTable 转换为 对象List
        /// </summary>
        /// <typeparam name="T"></typeparam>
        /// <param name="dt"></param>
        /// <returns></returns>
        public static List<T> DataTableToEntities<T>(this DataTable dt) where T : class, new()
        {
            if (null == dt || dt.Rows.Count == ) { return null; }
            List<T> entities = new List<T>();

            foreach (DataRow row in dt.Rows)
            {
                PropertyInfo[] pArray = typeof(T).GetProperties();
                T entity = new T();

                Array.ForEach<PropertyInfo>(pArray, p =>
                {
                    object cellvalue = row[p.Name];
                    if (cellvalue != DBNull.Value)
                    {
                        //经过了几个版本的迭代，最后一个为最新的，摘自网上，已附原文地址

                        //4、原地址：https://blog.csdn.net/Simon1003/article/details/80839744
                        if (!p.PropertyType.IsGenericType)
                        {
                            p.SetValue(entity, Convert.ChangeType(cellvalue, p.PropertyType), null);
                        }
                        else
                        {
                            Type genericTypeDefinition = p.PropertyType.GetGenericTypeDefinition();
                            if (genericTypeDefinition == typeof(Nullable<>))
                            {
                                p.SetValue(entity, Convert.ChangeType(cellvalue, Nullable.GetUnderlyingType(p.PropertyType)), null);
                            }
                            else
                            {
                                throw new Exception("genericTypeDefinition != typeof(Nullable<>)");
                            }
                        }

                        //3、原地址：https://blog.csdn.net/hebbers/article/details/78957569
                        //Type type = p.PropertyType;
                        //if (type.IsGenericType && type.GetGenericTypeDefinition().Equals(typeof(Nullable<>)))//判断convertsionType是否为nullable泛型类
                        //{
                        //    //如果type为nullable类，声明一个NullableConverter类，该类提供从Nullable类到基础基元类型的转换
                        //    System.ComponentModel.NullableConverter nullableConverter = new System.ComponentModel.NullableConverter(type);
                        //    //将type转换为nullable对的基础基元类型
                        //    type = nullableConverter.UnderlyingType;
                        //}
                        //p.SetValue(entity, Convert.ChangeType(cellvalue, type), null);

                        //2、自定义 这种很傻，但当前解决速度最快
                        //if (p.PropertyType.Name.Equals("Int32"))
                        //{
                        //    p.SetValue(entity, Convert.ToInt32(value), null);
                        //}
                        //else if (p.PropertyType.Name.Equals("String"))
                        //{
                        //    p.SetValue(entity, Convert.ToString(value), null);
                        //}
                        //else if (p.PropertyType.Name.Equals("Nullable`1"))
                        //{
                        //    p.SetValue(entity, Convert.ToInt32(value), null);
                        //}
                        ////其它类型 暂时不管 

                        //1、字段不为空可以用这种
                        //p.SetValue(entity, value, null);
                    }
                });
                entities.Add(entity);
            }
            return entities;
        }

        public static List<T> DataTableToEntities2<T>(this DataTable dt) where T : class, new()
        {
            if (null == dt || dt.Rows.Count == ) { return null; }
            List<T> entities = new List<T>();

            foreach (DataRow row in dt.Rows)
            {
                PropertyInfo[] pArray = typeof(T).GetProperties();
                T entity = new T();

                Array.ForEach<PropertyInfo>(pArray, p =>
                {
                    object cellvalue = row[p.Name];
                    if (cellvalue != DBNull.Value)
                    {
                        if (!p.PropertyType.IsGenericType)
                        {
                            p.SetValue(entity, Convert.ChangeType(cellvalue, p.PropertyType), null);
                        }
                        else
                        {
                            Type genericTypeDefinition = p.PropertyType.GetGenericTypeDefinition();
                            if (genericTypeDefinition == typeof(Nullable<>))
                            {
                                p.SetValue(entity, Convert.ChangeType(cellvalue, Nullable.GetUnderlyingType(p.PropertyType)), null);
                            }
                            else
                            {
                                throw new Exception("genericTypeDefinition != typeof(Nullable<>)");
                            }
                        }
                    }
                });
                entities.Add(entity);
            }
            return entities;
        }

        public static List<T> DataTableToEntities3<T>(DataTable dt) where T : class, new()
        {
            if (null == dt || dt.Rows.Count == ) { return null; }
            List<T> entities = new List<T>();

            foreach (DataRow row in dt.Rows)
            {
                PropertyInfo[] pArray = typeof(T).GetProperties();
                T entity = new T();

                Array.ForEach<PropertyInfo>(pArray, p =>
                {
                    object cellvalue = row[p.Name];
                    if (cellvalue != DBNull.Value)
                    {
                        //经过了几个版本的迭代，最后一个为最新的，摘自网上，已附原文地址

                        //4、原地址：https://blog.csdn.net/Simon1003/article/details/80839744
                        if (!p.PropertyType.IsGenericType)
                        {
                            p.SetValue(entity, Convert.ChangeType(cellvalue, p.PropertyType), null);
                        }
                        else
                        {
                            Type genericTypeDefinition = p.PropertyType.GetGenericTypeDefinition();
                            if (genericTypeDefinition == typeof(Nullable<>))
                            {
                                p.SetValue(entity, Convert.ChangeType(cellvalue, Nullable.GetUnderlyingType(p.PropertyType)), null);
                            }
                            else
                            {
                                throw new Exception("genericTypeDefinition != typeof(Nullable<>)");
                            }
                        }

                        //3、原地址：https://blog.csdn.net/hebbers/article/details/78957569
                        //Type type = p.PropertyType;
                        //if (type.IsGenericType && type.GetGenericTypeDefinition().Equals(typeof(Nullable<>)))//判断convertsionType是否为nullable泛型类
                        //{
                        //    //如果type为nullable类，声明一个NullableConverter类，该类提供从Nullable类到基础基元类型的转换
                        //    System.ComponentModel.NullableConverter nullableConverter = new System.ComponentModel.NullableConverter(type);
                        //    //将type转换为nullable对的基础基元类型
                        //    type = nullableConverter.UnderlyingType;
                        //}
                        //p.SetValue(entity, Convert.ChangeType(cellvalue, type), null);

                        //2、自定义 这种很傻，但当前解决速度最快
                        //if (p.PropertyType.Name.Equals("Int32"))
                        //{
                        //    p.SetValue(entity, Convert.ToInt32(value), null);
                        //}
                        //else if (p.PropertyType.Name.Equals("String"))
                        //{
                        //    p.SetValue(entity, Convert.ToString(value), null);
                        //}
                        //else if (p.PropertyType.Name.Equals("Nullable`1"))
                        //{
                        //    p.SetValue(entity, Convert.ToInt32(value), null);
                        //}
                        ////其它类型 暂时不管 

                        //1、字段不为空可以用这种
                        //p.SetValue(entity, value, null);
                    }
                });
                entities.Add(entity);
            }
            return entities;
        }

        /// <summary>
        /// 跟属性赋值
        /// </summary>
        /// <typeparam name="T"></typeparam>
        /// <param name="model"></param>
        /// <param name="name"></param>
        /// <param name="value"></param>
        public static void AssignValueToAttribute<T>(T model, string name, object value)
        {
            Type t = model.GetType();
            var p = t.GetProperty(name);

            if (!p.PropertyType.IsGenericType)
            {
                p.SetValue(model, Convert.ChangeType(value, p.PropertyType), null);
            }
            else
            {
                Type genericTypeDefinition = p.PropertyType.GetGenericTypeDefinition();
                if (genericTypeDefinition == typeof(Nullable<>))
                {
                    p.SetValue(model, Convert.ChangeType(value, Nullable.GetUnderlyingType(p.PropertyType)), null);
                }
                else
                {
                    throw new Exception("genericTypeDefinition != typeof(Nullable<>)");
                }
            }
        }

        /// <summary>
        /// 获取属性值
        /// </summary>
        /// <typeparam name="T"></typeparam>
        /// <param name="model"></param>
        /// <param name="name"></param>
        /// <returns></returns>
        public static object GetValueByAttribute<T>(T model, string name)
        {
            Type t = model.GetType();
            var p = t.GetProperty(name);
            return p.GetValue(model, null);
        }

        /// <summary>
        /// 跟属性赋值
        /// </summary>
        /// <typeparam name="T"></typeparam>
        /// <param name="model"></param>
        /// <param name="name"></param>
        /// <param name="model_old"></param>
        public static void AssignValueToAttribute<T>(T model, string name, T model_old)
        {
            Type t = model_old.GetType();
            var p = t.GetProperty(name);
            object obj = p.GetValue(model_old, null);

            AssignValueToAttribute(model, name, obj);
        }

    }
}