.net对反射（Type）的应用实现遍历类的属性和值并实现简单的增删改查模板

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我是靠谱客的博主愤怒小兔子，最近开发中收集的这篇文章主要介绍.net对反射（Type）的应用实现遍历类的属性和值并实现简单的增删改查模板，觉得挺不错的，现在分享给大家，希望可以做个参考。

概述

作用：反射可以通过程序操作实体类的属性值，对实体类遍历输出更改

1.反射的基本属性和方法的用法


Type t = typeof(T);//获取T类的反射
T model=new T();
t.GetProperties();获取类的属性集合
t.Name//获取类名
t.GetField("id");//获取字段
t.GetProperty("ID")//获取指定属性
t.GetProperty("ID").GetValue(model, null)//获取指定属性实体类model的值
t.GetProperty("ID").PropertyType == typeof(string)//判断指定属性类型
t.GetProperty("ID").SetValue(model, dr[item.ColumnName])//在model中为指定属性赋值

2.简单模板的书写


public class ICustomBaseDAL<T> :IBaseDAL<T>
where T : new()
{
//重构返回model的方法
public T Result(DataTable dt, Type t, DataRow dr)
{
T model = new T();
foreach (DataColumn item in dt.Columns)
{
//获取中获值t.GetProperty(item.ColumnName)如果包韩则不为空
PropertyInfo proper = t.GetProperty(item.ColumnName);
if (proper != null)
{
//如果为空给model付null
if (dr[item.ColumnName].ToString()=="")
{
proper.SetValue(model,null);
continue;
}
//将值赋给model
proper.SetValue(model, dr[item.ColumnName]);//设置值第一个参数设置到的实体类第二个设置的值
}
}
return model;
}
//判断是为可用类型过滤不可用属性
public bool GetWhere(Type t, PropertyInfo pope)
{
//以Extend结尾跳出循环
if (pope.Name.EndsWith("Extend"))//自己扩展的属性不参与查询
{
return false;
}
//将能判断的都加进去
Type[] types = {typeof(string), typeof(DateTime), typeof(DateTime?), typeof(int?), typeof(int), typeof(double), typeof(double?), typeof(decimal), typeof(decimal?) };
if (types.Contains(t))
{
return true;
}
return false;
}
public virtual int Update(T model)//根据model修改必须有id
{
Type t = typeof(T);
PropertyInfo[] popes = t.GetProperties();
List<string> fields = new List<string>();
List<string> values = new List<string>();
string tableName = t.Name;//获取类的名称
PropertyInfo pID = t.GetProperty("ID");//获取类对应的Id
string idValue = pID.GetValue(model, null).ToString();//获取属性id的值//model是指从实体对象中获取
foreach (PropertyInfo pope in popes)
{
string proName = pope.Name;
//pope.PropertyType获取属性类型
bool whereOk = GetWhere(pope.PropertyType, pope);
if (!whereOk)
{
continue;
}
if (proName == "ID")
{
continue;
}
object val = pope.GetValue(model, null);
//if (val == null)
//{
//
continue;
//}
if (pope.PropertyType == typeof(string) || pope.PropertyType == typeof(DateTime) || pope.PropertyType == typeof(DateTime?))
{
values.Add(proName + "='" + val + "'");
}
else
{
values.Add(proName + "=" + val + "");
}
}
string value = string.Join(",", values.ToArray());
string sql = " update
[" + tableName + "]
set " + value + " where id= " + idValue;
return SqlHelper.Curtsql(sql);
}
public virtual int Add(T model)//添加一条数据
{
Type t = typeof(T);
PropertyInfo[] popes = t.GetProperties();
List<string> fields = new List<string>();
List<string> values = new List<string>();
string tableName = t.Name;//获取类的名称
//PropertyInfo pID = t.GetProperty("ID");//获取类对应的Id
//string idValue = pID.GetValue(model, null).ToString();//获取属性id的值
foreach (PropertyInfo pope in popes)
{
string proName = pope.Name;
//pope.PropertyType获取属性类型
bool whereOk = GetWhere(pope.PropertyType,pope);
if (!whereOk)
{
continue;
}
if (proName == "ID")
{
continue;
}
object val = pope.GetValue(model, null);
if (val != null)
{
fields.Add(proName);
if (pope.PropertyType == typeof(string) || pope.PropertyType == typeof(DateTime) || pope.PropertyType == typeof(DateTime?))
{
values.Add("'" + val + "'");
}
else
{
values.Add("" + val + "");
}
}
}
string field = string.Join(",", fields.ToArray());
string value = string.Join(",", values.ToArray());
string sql = "insert into
[" + tableName + "]
(" + field + ") values(" + value + ") ";
return SqlHelper.Curtsql(sql);
}
public virtual int Delete(int id)//更具id删除
{
Type t = typeof(T);
PropertyInfo[] popes = t.GetProperties();
//
List<string> fields = new List<string>();
//
List<string> values = new List<string>();
string tableName = t.Name;//获取类的名称
//
PropertyInfo pID = t.GetProperty("ID");//获取类对应的Id
//string idValue = pID.GetValue(model, null).ToString();//获取属性id的值
string sql = " delete from [" + tableName + "] where id=" + id;
return SqlHelper.Curtsql(sql);
}
public virtual T Search(int id)//根据id查询
{
Type t = typeof(T);
PropertyInfo[] popes = t.GetProperties();
string filter = "*";
string tableName = "[" + t.Name + "]";//获取类的名称
string where = " and id=" + id;
DataTable dt = SqlHelper.Search(filter, tableName, where);
DataRow dr = dt.Rows[0];
T model = Result(dt, t, dr);
return model;
}
public string GetWhereModel(T model)//够造where条件
{
Type t = typeof(T);
PropertyInfo[] popes = t.GetProperties();
StringBuilder values = new StringBuilder();
if (model != null)
{
foreach (PropertyInfo pope in popes)
{
string proName = pope.Name;
//pope.PropertyType获取属性类型
bool whereOk = GetWhere(pope.PropertyType,pope);
if (!whereOk)
{
continue;
}
object val = pope.GetValue(model, null);
if (val == null)
{
continue;
}
if (pope.PropertyType == typeof(int) || pope.PropertyType == typeof(int?))
{
if (val.ToString() == "0" || val.ToString() == "-1")
{
continue;
}
}
if (pope.PropertyType == typeof(string) || pope.PropertyType == typeof(DateTime) || pope.PropertyType == typeof(DateTime?))
{
values.Append(" and " + proName + " like '%" + val + "%'");
}
else
{
values.Append(" and " + proName + "=" + val + "");
}
}
}
return
values.ToString();
}
public virtual List<T> DataByPager(T model, int pageSize, int pageIndex, bool isAsc, out int count)//分页查询
{
Type t = typeof(T);
PropertyInfo[] popes = t.GetProperties();
string where = GetWhereModel(model);
List<T> list = new List<T>();
QueryBy query = new QueryBy();
query.Table = "[" + t.Name + "]";
query.Filter = "*";
query.Where = where;
query.sortColumn = "ID";
query.IsAsc = isAsc;
query.PageSize = pageSize;
query.PageIndex = pageIndex;
DataTable dt = CreateDateByPager.dataByPager(query);
count = query.Count;
foreach (DataRow dr in dt.Rows)
{
T _model = Result(dt, t, dr);
list.Add(_model);
}
return list;
}
//根据where条件查询内部构造where语句查询所有字段
public virtual List<T> Search(T model)
{
Type t = typeof(T);
List<T> list = new List<T>();
string filter = "*";
string tableName = "[" + t.Name + "]";//获取类的名称
string where = GetWhereModel(model);
DataTable dt = SqlHelper.Search(filter, tableName, where);
foreach (DataRow dr in dt.Rows)
{
T _model = Result(dt, t, dr);
list.Add(_model);
}
return list;
}
//根据指定条件修改
public int Update(T model, string[] propertyNames)
{
Type t = typeof(T);
PropertyInfo[] popes = t.GetProperties();
List<string> fields = new List<string>();
List<string> values = new List<string>();
string tableName = t.Name;//获取类的名称
PropertyInfo pID = t.GetProperty("ID");//获取类对应的Id
string idValue = pID.GetValue(model, null).ToString();//获取属性id的值//model是指从实体对象中获取
foreach (PropertyInfo pope in popes)
{
string proName = pope.Name;
bool whereOk = GetWhere(pope.PropertyType,pope);
if (!whereOk)
{
continue;
}
if (proName == "ID")
{
continue;
}
object val = pope.GetValue(model, null);
//if (val == null)
//{
//
continue;
//}
//判断是否包含修改的元素
if (propertyNames.Contains(proName))
{
if (pope.PropertyType == typeof(string) || pope.PropertyType == typeof(DateTime) || pope.PropertyType == typeof(DateTime?))
{
values.Add(proName + "='" + val + "'");
}
else
{
values.Add(proName + "=" + val + "");
}
}
}
string value = string.Join(",", values.ToArray());
string sql = " update
[" + tableName + "]
set " + value + " where id= " + idValue;
return SqlHelper.Curtsql(sql);
}
//实现批量删除
public int Delete(string ids)
{
Type t = typeof(T);
PropertyInfo[] popes = t.GetProperties();
//
List<string> fields = new List<string>();
//
List<string> values = new List<string>();
string tableName = t.Name;//获取类的名称
//
PropertyInfo pID = t.GetProperty("ID");//获取类对应的Id
//string idValue = pID.GetValue(model, null).ToString();//获取属性id的值
string sql = " delete from [" + tableName + "] where id in ("+ids+")";
return SqlHelper.Curtsql(sql);
}
}