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Entity Framework泛型封装
Entity Framework本身的增删改查其实 已经很方便了，不过做项目的时候用的多了也就觉得有点累了，每个业务实体基本上都涉及到到了增删改查这四个基本的要素，至于封装每个公司可能都不一样，接口，设计模式都用的眼花缭乱，我闲来没事就搞个简单的封装Helper，Github上也有关于EF的扩展Libray，具体没有用过，公司的有自己的封装，自己也没怎么弄，具体地址:https://github.com/loresoft/EntityFramework.Extended.
首先来看段代码，model和context是从数据中直接生成，你可以选择自己习惯的方式:
//新增 User addUser = new User(); addUser.PersonID = 3; addUser.UserName = "keso"; dbContext.Entry<User>(addUser).State = EntityState.Added; dbContext.SaveChanges(); //修改 User updateUser = new User(); dbContext.Users.Where(item => item.ID == 2).OrderBy(item => item.ID); updateUser.UserName = updateUser.UserName + "测试"; dbContext.Entry<User>(updateUser).State = EntityState.Modified; dbContext.SaveChanges(); //删除 User delUser = dbContext.Users.Where(item => item.ID == 2).First(); dbContext.Entry<User>(delUser).State = EntityState.Deleted; dbContext.SaveChanges();
如果每个业务实体都这么写一遍，估计公司水准有待提高，而且开发的也该跳起来骂人，本人只是简单封装下新建一个EFHelper，实际开发会封装的更多，不过底层处理是不变的
class EFHelpler<T> where T : class { //... } 新增
方法:
/// <summary> /// 实体新增 /// </summary> /// <param name="model"></param> public void add(params T[] paramList) { foreach (var model in paramList) { dbContext.Entry<T>(model).State = EntityState.Added; } dbContext.SaveChanges(); }调用:
EFHelpler<User> helper = new EFHelpler<User>(); BaseContext dbContext = new BaseContext(); //新增 List<User> listUser = new List<User>(); for (int i = 0; i < 2; i++) { User user = new User(); user.PersonID = i; user.UserName = "FlyElehant" + i; listUser.Add(user); } helper.add(listUser.ToArray()); Console.WriteLine("新增成功");查询
查询分了两种，一种是简单的查询，一种是分页的：
/// <summary> /// 实体查询 /// </summary> public IEnumerable<T> getSearchList(System.Linq.Expressions.Expression<Func<T, bool>> where) { return dbContext.Set<T>().Where(where); } /// <summary> /// 实体分页查询 /// </summary> /// <typeparam name="TKey"></typeparam> /// <param name="where"></param> /// <param name="orderBy"></param> /// <param name="pageSize"></param> /// <param name="pageIndex"></param> /// <returns></returns> public IEnumerable<T> getSearchListByPage<TKey>(Expression<Func<T, bool>> where, Expression<Func<T, TKey>> orderBy, int pageSize, int pageIndex) { return dbContext.Set<T>().Where(where).OrderByDescending(orderBy).Skip((pageIndex - 1) * pageSize).Take(pageSize); }简单调用，第二个方式除了分页之外，主要是查询的时候指定一定OrderBy的类型，也就是TKey:
var query = helper.getSearchList(item => item.UserName.Contains("keso")); var queryMulti = helper.getSearchListByPage<int>(item => item.UserName.Contains("FlyElehant"), order => order.PersonID, 2, 1); query = queryMulti; foreach (User user in query) { Console.WriteLine(user.UserName); }修改
修改代码稍微读了几行，主要是用到了一下反射:
/// <summary> /// 按照条件修改数据 /// </summary> /// <param name="where"></param> /// <param name="dic"></param> public void update(Expression<Func<T, bool>> where, Dictionary<string, object> dic) { IEnumerable<T> result = dbContext.Set<T>().Where(where).ToList(); Type type = typeof(T); List<PropertyInfo> propertyList = type.GetProperties(System.Reflection.BindingFlags.Public | System.Reflection.BindingFlags.Instance).ToList(); //遍历结果集 foreach (T entity in result) { foreach (PropertyInfo propertyInfo in propertyList) { string propertyName = propertyInfo.Name; if (dic.ContainsKey(propertyName)) { //设置值 propertyInfo.SetValue(entity, dic[propertyName], null); } } } dbContext.SaveChanges(); }调用:
Dictionary<string,object> dic=new Dictionary<string,object>(); dic.Add("PersonID",2); dic.Add("UserName","keso"); helper.update(item => item.UserName.Contains("keso"), dic); Console.WriteLine("修改成功");删除
方法:
/// <summary> /// 实体删除 /// </summary> /// <param name="model"></param> public void delete(params T[] paramList) { foreach (var model in paramList) { dbContext.Entry<T>(model).State = EntityState.Deleted; } dbContext.SaveChanges(); }调用:
var query = helper.getSearchList(item => item.UserName.Contains("keso")); helper.delete(query.ToArray());完整的EFHelper:
class EFHelpler<T> where T : class { BaseContext dbContext = new BaseContext(); /// <summary> /// 实体新增 /// </summary> /// <param name="model"></param> public void add(params T[] paramList) { foreach (var model in paramList) { dbContext.Entry<T>(model).State = EntityState.Added; } dbContext.SaveChanges(); } /// <summary> /// 实体查询 /// </summary> public IEnumerable<T> getSearchList(System.Linq.Expressions.Expression<Func<T, bool>> where) { return dbContext.Set<T>().Where(where); } /// <summary> /// 实体分页查询 /// </summary> /// <typeparam name="TKey"></typeparam> /// <param name="where"></param> /// <param name="orderBy"></param> /// <param name="pageSize"></param> /// <param name="pageIndex"></param> /// <returns></returns> public IEnumerable<T> getSearchListByPage<TKey>(Expression<Func<T, bool>> where, Expression<Func<T, TKey>> orderBy, int pageSize, int pageIndex) { return dbContext.Set<T>().Where(where).OrderByDescending(orderBy).Skip((pageIndex - 1) * pageSize).Take(pageSize); } /// <summary> /// 实体删除 /// </summary> /// <param name="model"></param> public void delete(params T[] paramList) { foreach (var model in paramList) { dbContext.Entry<T>(model).State = EntityState.Deleted; } dbContext.SaveChanges(); } /// <summary> /// 按照条件修改数据 /// </summary> /// <param name="where"></param> /// <param name="dic"></param> public void update(Expression<Func<T, bool>> where, Dictionary<string, object> dic) { IEnumerable<T> result = dbContext.Set<T>().Where(where).ToList(); Type type = typeof(T); List<PropertyInfo> propertyList = type.GetProperties(System.Reflection.BindingFlags.Public | System.Reflection.BindingFlags.Instance).ToList(); //遍历结果集 foreach (T entity in result) { foreach (PropertyInfo propertyInfo in propertyList) { string propertyName = propertyInfo.Name; if (dic.ContainsKey(propertyName)) { //设置值 propertyInfo.SetValue(entity, dic[propertyName], null); } } } dbContext.SaveChanges(); } }个人Demo难免有表达不当或者技术失误的地方，如有不当，请多多指出，感激不尽~
Entity Framework泛型封装
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