DtToList.cs 5.08 KB
using System;
using System.Collections;
using System.Collections.Generic;
using System.ComponentModel;
using System.ComponentModel.DataAnnotations;
using System.Data;
using System.Linq;
using System.Reflection;
using System.Text;
using System.Threading.Tasks;

namespace HHECS.Infrastructure.CommonHelper
{
    public class DtToList
    {
        /// <summary>
        /// 根据实体类创建表结构
        /// </summary>
        /// <param name="model">实体类</param>
        /// <returns></returns>
        public static DataTable CreateDataTable<T>(T model, List<string> cols)
        {
            DataTable dataTable = new DataTable(typeof(T).Name);
            foreach (PropertyInfo propertyInfo in typeof(T).GetProperties())
            {
                try
                {
                    if (cols.Contains(propertyInfo.Name))
                    {
                        dataTable.Columns.Add(new DataColumn(propertyInfo.Name, propertyInfo.PropertyType));
                    }
                }
                catch (Exception ex)
                {
                    dataTable.Columns.Add(new DataColumn(propertyInfo.Name, typeof(string)));
                }
            }
            return dataTable;
        }

        /// <summary>
        /// List转换成DataTable
        /// </summary>
        /// <param name="modelList">List集合</param>
        /// <returns></returns>
        public static DataTable ListConvertToDataTable<T>(List<T> modelList, List<string> cols)
        {
            if (modelList == null || modelList.Count == 0)
            {
                return null;
            }
            DataTable dt = CreateDataTable(modelList[0], cols);

            foreach (T model in modelList)
            {
                DataRow dataRow = dt.NewRow();
                foreach (PropertyInfo propertyInfo in typeof(T).GetProperties())
                {
                    try
                    {
                        if (cols.Contains(propertyInfo.Name))
                        {
                            dataRow[propertyInfo.Name] = propertyInfo.GetValue(model, null);
                        }
                    }
                    catch (Exception)
                    {
                    }
                }
                dt.Rows.Add(dataRow);
            }
            return dt;
        }
        /// <summary>
        /// datatable转list
        /// </summary>
        /// <param name="dt"></param>
        /// <returns></returns>
        public static List<T> ConvertToModel<T>(DataTable dt) where T : new()
        {

            List<T> ts = new List<T>();// 定义集合
            string tempName = "";
            foreach (DataRow dr in dt.Rows)
            {
                T t = new T();
                PropertyInfo[] propertys = t.GetType().GetProperties();// 获得此模型的公共属性
                foreach (PropertyInfo pi in propertys)
                {
                    tempName = pi.Name;
                    if (dt.Columns.Contains(tempName))
                    {
                        if (!pi.CanWrite) continue;
                        object value = dr[tempName];
                        if (value != DBNull.Value)
                            pi.SetValue(t, value, null);
                    }
                }
                ts.Add(t);
            }
            return ts;
        }

        /// <summary>
        /// list转datatable
        /// </summary>
        /// <typeparam name="T"></typeparam>
        /// <param name="collection"></param>
        /// <returns></returns>
        public static DataTable ListToDt<T>(IEnumerable<T> collection)
        {
            var props = typeof(T).GetProperties().Where(t => t.GetCustomAttribute(typeof(EditableAttribute)) == null);
            var dt = new DataTable();
            foreach (var item in props)
            {
                DataColumn dataColumn;
                Type colType = item.PropertyType;
                if (colType.IsGenericType && colType.GetGenericTypeDefinition() == typeof(Nullable<>))
                {
                    colType = colType.GetGenericArguments()[0];
                }
                var attr = (DescriptionAttribute)item.GetCustomAttribute(typeof(DescriptionAttribute));
                if (attr != null)
                {
                    dataColumn = new DataColumn(attr.Description, colType);
                }
                else
                {
                    dataColumn = new DataColumn(item.Name, colType);
                }
                dt.Columns.Add(dataColumn);
            }
            if (collection.Count() > 0)
            {
                for (int i = 0; i < collection.Count(); i++)
                {
                    ArrayList tempList = new ArrayList();
                    foreach (PropertyInfo pi in props)
                    {
                        object obj = pi.GetValue(collection.ElementAt(i), null);
                        tempList.Add(obj);
                    }
                    object[] array = tempList.ToArray();
                    dt.LoadDataRow(array, true);
                }
            }
            return dt;
        }
    }
}