2

schangxiang@126.com

2024-10-01 ffa9dc9c2d28c0b8d88b26d483ba9667e316db01

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using System;
using System.Collections;
using System.Collections.Generic;
using System.ComponentModel;
using System.Data;
using System.Linq;
using System.Reflection;
using System.Text;
using System.Threading.Tasks;
using System.Windows.Forms;
using WZ.Useful.Commons;
 
 
namespace iWareCommon.Utils
{
    public static class DataTableHelper
    {
        public static DataTable ToDataTable<T>(IList<T> list)
        {
            return ToDataTable<T>(list, null);
        }
        /// <summary>
        /// 将泛型集合类转换成DataTable
        /// </summary>
        /// <typeparam name="T">集合项类型</typeparam>
        /// <param name="list">集合</param>
        /// <param name="propertyName">需要返回的列的列名</param>
        /// <returns>数据集(表)</returns>
        public static DataTable ToDataTable<T>(IList<T> list, params string[] propertyName)
        {
            List<string> propertyNameList = new List<string>();
            if (propertyName != null)
                propertyNameList.AddRange(propertyName);
 
            DataTable result = new DataTable();
            if (list.Count > 0)
            {
                PropertyInfo[] propertys = list[0].GetType().GetProperties();
                foreach (PropertyInfo pi in propertys)
                {
                    try
                    {
                        Type nullInt32 = typeof(Int32?);
                        Type classicInt32 = typeof(Int32);
                        if (propertyNameList.Count == 0)
                        {
                            //result.Columns.Add(pi.Name, pi.PropertyType);
                            var tmp = pi.PropertyType.UnderlyingSystemType.ToString();
                            result.Columns.Add(pi.Name, tmp.Contains("System.Nullable") ? classicInt32 : pi.PropertyType);
                        }
                        else
                        {
 
                            if (propertyNameList.Contains(pi.Name))
                            {
                                var tmp = pi.PropertyType.UnderlyingSystemType.ToString();
                                result.Columns.Add(pi.Name, tmp.Contains("System.Nullable") ? classicInt32 : pi.PropertyType);
                            }
                        }
                    }
                    catch (Exception ex)
                    {
                        MessageBox.Show(ex.ToString());
                    }
                }
 
                for (int i = 0; i < list.Count; i++)
                {
                    ArrayList tempList = new ArrayList();
                    foreach (PropertyInfo pi in propertys)
                    {
                        if (propertyNameList.Count == 0)
                        {
                            object obj = pi.GetValue(list[i], null);
                            tempList.Add(obj);
                        }
                        else
                        {
                            if (propertyNameList.Contains(pi.Name))
                            {
                                object obj = pi.GetValue(list[i], null);
                                tempList.Add(obj);
                            }
                        }
                    }
                    object[] array = tempList.ToArray();
                    result.LoadDataRow(array, true);
                }
            }
            return result;
        }
        public static void DataSetToExcel(DataTable ds)
        {
            string filePath = FileDialogHelper.SaveExcel();
            WZ.Useful.Commons.ExcelHelper.DataSetToExcel(ds, filePath);
 
        }
 
        /// <summary>
        /// 将linq查询转换为datatable
        /// </summary>
        /// <typeparam name="T"></typeparam>
        /// <param name="array"></param>
        /// <returns></returns>
        public static DataTable CopyToDataTable<T>(IEnumerable<T> array)
        {
            if (array == null)
            {
                return null;
            }
            var ret = new DataTable();
            foreach (PropertyDescriptor dp in TypeDescriptor.GetProperties(typeof(T)))
                ret.Columns.Add(dp.Name);
 
            foreach (T item in array)
            {
                var Row = ret.NewRow();
                foreach (PropertyDescriptor dp in TypeDescriptor.GetProperties(typeof(T)))
                    Row[dp.Name] = dp.GetValue(item);
                ret.Rows.Add(Row);
            }
            return ret;
        }
 
 
        /// <summary>
        /// 根据列名,将linq查询转换为datatable
        /// </summary>
        /// <typeparam name="T"></typeparam>
        /// <param name="array"></param>
        /// <returns></returns>
        public static DataTable CopyToDataTable<T>(IEnumerable<T> array, string[] columns, string[] columnNames)
        {
            if (array == null)
            {
                return null;
            }
            var ret = new DataTable();
            foreach (var item in columnNames)
            {
                ret.Columns.Add(item);
            }
 
            foreach (T item in array)
            {//遍历实体类中的每一个实体
                var Row = ret.NewRow();
                for (int i = 0; i < columns.Length; i++)
                {
                    foreach (PropertyDescriptor dp in TypeDescriptor.GetProperties(typeof(T)))
                    {//遍历一个实体类的所有属性 
                        if (dp.Name == columns[i])
                        {
                            Row[columnNames[i]] = dp.GetValue(item);
                            break;
                        }
                    }
                }
                ret.Rows.Add(Row);
            }
            return ret;
        }
 
    }
}