常用方法 反射常见方法
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/// <summary> /// DataTable 转换为 对象List /// </summary> /// <typeparam name="T"></typeparam> /// <param name="dt"></param> /// <returns></returns> public static List<T> DataTableToEntities<T>(this DataTable dt) where T : class, new() if (null == dt || dt.Rows.Count == 0) return null; List<T> entities = new List<T>(); foreach (DataRow row in dt.Rows) PropertyInfo[] pArray = typeof(T).GetProperties(); T entity = new T(); Array.ForEach<PropertyInfo>(pArray, p => object cellvalue = row[p.Name]; if (cellvalue != DBNull.Value) //经过了几个版本的迭代,最后一个为最新的,摘自网上,已附原文地址 //4、原地址:https://blog.csdn.net/Simon1003/article/details/80839744 if (!p.PropertyType.IsGenericType) p.SetValue(entity, Convert.ChangeType(cellvalue, p.PropertyType), null); else Type genericTypeDefinition = p.PropertyType.GetGenericTypeDefinition(); if (genericTypeDefinition == typeof(Nullable<>)) p.SetValue(entity, Convert.ChangeType(cellvalue, Nullable.GetUnderlyingType(p.PropertyType)), null); else throw new Exception("genericTypeDefinition != typeof(Nullable<>)"); //3、原地址:https://blog.csdn.net/hebbers/article/details/78957569 //Type type = p.PropertyType; //if (type.IsGenericType && type.GetGenericTypeDefinition().Equals(typeof(Nullable<>)))//判断convertsionType是否为nullable泛型类 // // //如果type为nullable类,声明一个NullableConverter类,该类提供从Nullable类到基础基元类型的转换 // System.ComponentModel.NullableConverter nullableConverter = new System.ComponentModel.NullableConverter(type); // //将type转换为nullable对的基础基元类型 // type = nullableConverter.UnderlyingType; // //p.SetValue(entity, Convert.ChangeType(cellvalue, type), null); //2、自定义 这种很傻,但当前解决速度最快 //if (p.PropertyType.Name.Equals("Int32")) // // p.SetValue(entity, Convert.ToInt32(value), null); // //else if (p.PropertyType.Name.Equals("String")) // // p.SetValue(entity, Convert.ToString(value), null); // //else if (p.PropertyType.Name.Equals("Nullable`1")) // // p.SetValue(entity, Convert.ToInt32(value), null); // ////其它类型 暂时不管 //1、字段不为空可以用这种 //p.SetValue(entity, value, null); ); entities.Add(entity); return entities; public static List<T> DataTableToEntities2<T>(this DataTable dt) where T : class, new() if (null == dt || dt.Rows.Count == 0) return null; List<T> entities = new List<T>(); foreach (DataRow row in dt.Rows) PropertyInfo[] pArray = typeof(T).GetProperties(); T entity = new T(); Array.ForEach<PropertyInfo>(pArray, p => object cellvalue = row[p.Name]; if (cellvalue != DBNull.Value) if (!p.PropertyType.IsGenericType) p.SetValue(entity, Convert.ChangeType(cellvalue, p.PropertyType), null); else Type genericTypeDefinition = p.PropertyType.GetGenericTypeDefinition(); if (genericTypeDefinition == typeof(Nullable<>)) p.SetValue(entity, Convert.ChangeType(cellvalue, Nullable.GetUnderlyingType(p.PropertyType)), null); else throw new Exception("genericTypeDefinition != typeof(Nullable<>)"); ); entities.Add(entity); return entities; public static List<T> DataTableToEntities3<T>(DataTable dt) where T : class, new() if (null == dt || dt.Rows.Count == 0) return null; List<T> entities = new List<T>(); foreach (DataRow row in dt.Rows) PropertyInfo[] pArray = typeof(T).GetProperties(); T entity = new T(); Array.ForEach<PropertyInfo>(pArray, p => object cellvalue = row[p.Name]; if (cellvalue != DBNull.Value) //经过了几个版本的迭代,最后一个为最新的,摘自网上,已附原文地址 //4、原地址:https://blog.csdn.net/Simon1003/article/details/80839744 if (!p.PropertyType.IsGenericType) p.SetValue(entity, Convert.ChangeType(cellvalue, p.PropertyType), null); else Type genericTypeDefinition = p.PropertyType.GetGenericTypeDefinition(); if (genericTypeDefinition == typeof(Nullable<>)) p.SetValue(entity, Convert.ChangeType(cellvalue, Nullable.GetUnderlyingType(p.PropertyType)), null); else throw new Exception("genericTypeDefinition != typeof(Nullable<>)"); //3、原地址:https://blog.csdn.net/hebbers/article/details/78957569 //Type type = p.PropertyType; //if (type.IsGenericType && type.GetGenericTypeDefinition().Equals(typeof(Nullable<>)))//判断convertsionType是否为nullable泛型类 // // //如果type为nullable类,声明一个NullableConverter类,该类提供从Nullable类到基础基元类型的转换 // System.ComponentModel.NullableConverter nullableConverter = new System.ComponentModel.NullableConverter(type); // //将type转换为nullable对的基础基元类型 // type = nullableConverter.UnderlyingType; // //p.SetValue(entity, Convert.ChangeType(cellvalue, type), null); //2、自定义 这种很傻,但当前解决速度最快 //if (p.PropertyType.Name.Equals("Int32")) // // p.SetValue(entity, Convert.ToInt32(value), null); // //else if (p.PropertyType.Name.Equals("String")) // // p.SetValue(entity, Convert.ToString(value), null); // //else if (p.PropertyType.Name.Equals("Nullable`1")) // // p.SetValue(entity, Convert.ToInt32(value), null); // ////其它类型 暂时不管 //1、字段不为空可以用这种 //p.SetValue(entity, value, null); ); entities.Add(entity); return entities; /// <summary> /// 跟属性赋值 /// </summary> /// <typeparam name="T"></typeparam> /// <param name="model"></param> /// <param name="name"></param> /// <param name="value"></param> public static void AssignValueToAttribute<T>(T model, string name, object value) Type t = model.GetType(); var p = t.GetProperty(name); if (!p.PropertyType.IsGenericType) p.SetValue(model, Convert.ChangeType(value, p.PropertyType), null); else Type genericTypeDefinition = p.PropertyType.GetGenericTypeDefinition(); if (genericTypeDefinition == typeof(Nullable<>)) p.SetValue(model, Convert.ChangeType(value, Nullable.GetUnderlyingType(p.PropertyType)), null); else throw new Exception("genericTypeDefinition != typeof(Nullable<>)"); /// <summary> /// 获取属性值 /// </summary> /// <typeparam name="T"></typeparam> /// <param name="model"></param> /// <param name="name"></param> /// <returns></returns> public static object GetValueByAttribute<T>(T model, string name) Type t = model.GetType(); var p = t.GetProperty(name); return p.GetValue(model, null); /// <summary> /// 跟属性赋值 /// 把一个对象的属性 赋值到 另一个对象 /// </summary> /// <typeparam name="T"></typeparam> /// <param name="model"></param> /// <param name="name"></param> /// <param name="model_old"></param> public static void AssignValueToAttribute<T>(T model, string name, T model_old) Type t = model_old.GetType(); var p = t.GetProperty(name); object obj = p.GetValue(model_old, null); AssignValueToAttribute(model, name, obj);
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