一、实现DataTable与实体类转换
1 /***
2 * Title："数据采集" 项目
3 * 主题：表和实体帮助类
4 * Description：
5 * 功能：
6 * 1、DataTable指定行数据转化为实体类
7 * 2、DataTable所有数据转换成实体类列表
8 * 3、实体类列表转换成DataTable
9 * Date：2021
10 * Version：0.1版本
11 * Author：Coffee
12 * Modify Recoder：
13 */
14
15 using System;
16 using System.Collections.Generic;
17 using System.Data;
18 using System.Linq;
19 using System.Reflection;
20 using System.Text;
21 using System.Threading.Tasks;
22
23 namespace Common
24 {
25 class TableToEntityHelper
26 {
27 /// <summary>
28 /// DataTable指定行数据转化为实体类
29 /// </summary>
30 /// <typeparam name="T">实体类</typeparam>
31 /// <param name="dataTable">dataTable</param>
32 /// <param name="rowIndex">需要解析行的索引</param>
33 /// <returns>返回当前指定行的实体类数据</returns>
34 public static T DataTableToEntity<T>(DataTable dataTable,int rowIndex) where T : new()
35 {
36 try
37 {
38 if (dataTable == null || dataTable.Rows.Count <= 0 || rowIndex<0)
39 {
40 return default(T);
41 }
42
43 //实例化实体类
44 T t = new T();
45 // 获取指定行数据
46 DataRow dr = dataTable.Rows[rowIndex];
47 // 获取所有列
48 DataColumnCollection columns = dataTable.Columns;
49
50 // 获得实体类的所有公共属性
51 PropertyInfo[] propertys = t.GetType().GetProperties();
52 foreach (PropertyInfo pi in propertys)
53 {
54 string name = pi.Name;
55 // 检查DataTable是否包含此列
56 if (columns.Contains(name))
57 {
58 if (!pi.CanWrite) continue;
59
60 object value = dr[name];
61 if (value != DBNull.Value)
62 {
63 pi.SetValue(t, value, null);
64 }
65 }
66 }
67 return t;
68
69 }
70 catch (Exception)
71 {
72
73 throw;
74 }
75 }
76
77 /// <summary>
78 /// DataTable所有数据转换成实体类列表
79 /// </summary>
80 /// <typeparam name="T">实体类</typeparam>
81 /// <param name="dt">DataTable</param>
82 /// <returns>返回实体类列表</returns>
83 public static List<T> DataTableToList<T>(DataTable dt) where T : new()
84 {
85 try
86 {
87 if (dt == null || dt.Rows.Count == 0)
88 {
89 return new List<T>();
90 }
91
92 // 实例化实体类和列表
93
94 List<T> list = new List<T>();
95
96 // 获取所有列
97 DataColumnCollection columns = dt.Columns;
98
99
100 foreach (DataRow dr in dt.Rows)
101 {
102 T t = new T();
103 // 获得实体类的所有公共属性
104 PropertyInfo[] propertys = t.GetType().GetProperties();
105
106 //循环比对且赋值
107 foreach (PropertyInfo p in propertys)
108 {
109 string name = p.Name;
110 // 检查DataTable是否包含此列
111 if (columns.Contains(name))
112 {
113 if (!p.CanWrite) continue;
114
115 object value = dr[name];
116
117 if (value != DBNull.Value)
118 {
119 是否需要转化
120 //if (value is int || value is float || value is decimal || value is double)
121 //{
122 // p.SetValue(t, value.ToString(), null);
123 //}
124 //else
125 //{
126 // p.SetValue(t, value, null);
127 //}
128
129 p.SetValue(t, value, null);
130 }
131 }
132 }
133 list.Add(t);
134 }
135 return list;
136 }
137 catch (Exception ex)
138 {
139 throw ex;
140 }
141 }
142
143 /// <summary>
144 /// 实体类列表转换成DataTable
145 /// </summary>
146 /// <param name="entityList">实体类列表</param>
147 /// <param name="excludeFields">排除字段</param>
148 /// <returns>返回实体类列表对应的DataTable</returns>
149 public static DataTable ListToDataTable<T>(List<T> entityList, List<string> excludeFields = null)
150 {
151 var countExclude = 0;
152 if (excludeFields != null)
153 countExclude = excludeFields.Count();
154
155 //检查实体集合不能为空
156 if (entityList == null || entityList.Count <= 0)
157 {
158 throw new Exception("需转换的集合为空");
159 }
160
161 //取出第一个实体的所有属性
162 Type entityType = entityList[0].GetType();
163 PropertyInfo[] entityProperties = entityType.GetProperties();
164
165
166
167 //实例化DataTable
168 DataTable dt = new DataTable();
169 for (int i = 0; i < entityProperties.Length; i++)
170 {
171 Type colType = entityProperties[i].PropertyType;
172 if ((colType.IsGenericType) && (colType.GetGenericTypeDefinition() == typeof(Nullable<>)))
173 {
174 colType = colType.GetGenericArguments()[0];
175 }
176 //排除列
177 string fieldName = entityProperties[i].Name;
178 if (excludeFields == null || !excludeFields.Contains(fieldName))
179 {
180 dt.Columns.Add(fieldName, colType);
181 }
182 }
183
184 //将所有entity添加到DataTable中
185 foreach (object entity in entityList)
186 {
187 //检查所有的的实体都为同一类型
188 if (entity.GetType() != entityType)
189 {
190 throw new Exception("要转换的集合元素类型不一致");
191 }
192 object[] entityValues = new object[dt.Columns.Count];
193 int icount = 0;
194 for (int i = 0; i < entityProperties.Length; i++)
195 {
196 //排除列
197 string fieldName = entityProperties[i].Name;
198 if (excludeFields == null || !excludeFields.Contains(fieldName))
199 {
200 entityValues[i - icount] = entityProperties[i].GetValue(entity, null);
201 }
202 else
203 {
204 icount++;
205 }
206 }
207 dt.Rows.Add(entityValues);
208 }
209
210 return dt;
211 }
212
213
214 }//Class_end
215
216 }
二、使用方法
1 //DataTable指定行数据转化为实体类
2 //获取到当前选中的所有行
3 int[] rows = gridView1.GetSelectedRows();
4 if (rows!=null && rows.Length>0)
5 {
6 //DataTable指定行数据转化为实体类
7 PeopleInfo peopleInfo = TableToEntityHelper.DataTableToEntity<PeopleInfo>(_dataTable, rows[0]);
8 }
9
10
11 //DataTable转换成实体类列表
12 List<PeopleInfo> peopleInfos = TableToEntityHelper.DataTableToList<PeopleInfo>(_dataTable);
13
14
15
16 //需要排除的类字段
17 List<string> execlude = new List<string>()
18 {
19 "ID","Sex"
20 };
21 //实体类列表转换成DataTable
22 DataTable dt = TableToEntityHelper.ListToDataTable(GetPeopeoInfos(),execlude);
23 //DataTable转换成实体类列表（用于查看效果）
24 List<PeopleInfo> peopleInfos2 = TableToEntityHelper.DataTableToList<PeopleInfo>(dt);
25
26
27
28
29
30 //模拟一个人员数据列表
31 private List<PeopleInfo> GetPeopeoInfos()
32 {
33 List<PeopleInfo> peopeoInfos = new List<PeopleInfo>()
34 {
35 new PeopleInfo{ ID="JK001",FullName="杨万里",Sex="男",IdCard="523033199001026780"},
36 new PeopleInfo{ ID="JK002",FullName="杨新宇",Sex="男",IdCard="523033199001026781"},
37 new PeopleInfo{ ID="JK003",FullName="钟一明",Sex="男",IdCard="523033199001026782"},
38 new PeopleInfo{ ID="JK004",FullName="张艺上",Sex="男",IdCard="523033199001026783"},
39 new PeopleInfo{ ID="JK004",FullName=" ",Sex="男",IdCard="523033199001026784"},
40 new PeopleInfo{ ID="JK006",FullName="胡一统",Sex="男",IdCard="523033199001026785"},
41 new PeopleInfo{ ID="JK007",FullName="马国富",Sex="男",IdCard="523033199001026786"},
42 new PeopleInfo{ ID="JK008",FullName="李宝军",Sex="男",IdCard="523033199001026787"},
43 new PeopleInfo{ ID="JK009",FullName="软文策",Sex="男",IdCard="523033199001026788"},
44 };
45
46
47 return peopeoInfos;
48 }
49
50
51 //人员信息模型类
52 private class PeopleInfo
53 {
54 public string ID { get; set; }
55 public string FullName { get; set; }
56 public string Sex { get; set; }
57 public string IdCard { get; set; }
58 }
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