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  • [c#.net]遍历一个对象中所有的属性和值

    利用反射

    SpDictItem sp = GetCFHObject.GetSpItem("655");
    PropertyInfo[] propertys = sp.GetType().GetProperties();
    foreach (PropertyInfo pinfo in propertys)
    {
        Response.Write("<br>" + pinfo.Name + "," + pinfo.GetValue(sp, null) + "<br>");
    }

    但是要判断可空类型的,可空类型的不能使用Property.GetValue(Model,null),如下

            /// <summary>
            /// C#反射遍历对象属性
            /// </summary>
            /// <typeparam name="T">对象类型</typeparam>
            /// <param name="model">对象</param>
            public static void ForeachClassProperties<T>(T model)
            {
                Type t = model.GetType();
                PropertyInfo[] PropertyList = t.GetProperties();
                foreach (PropertyInfo item in PropertyList)
                {
                    string name = item.Name;
                    object value = item.GetValue(model, null);
                    
                    Console.WriteLine(name);
     
                    if (item.PropertyType.IsGenericType && item.PropertyType.GetGenericTypeDefinition() == typeof(Nullable<>))
                    {
                        // If it is NULLABLE, then get the underlying type. eg if "Nullable<int>" then this will return just "int"
                        var columnType = item.PropertyType.GetGenericArguments()[0];
                        Console.WriteLine(columnType);
                    }
                    else
                    {
                        Console.WriteLine(item.PropertyType.Name);
                    }
                    Console.WriteLine();
                }
            }

    在我们的应用程序中我们使用类描述我们的业务对象,为我们产生一些报表之类的,那就依赖大量不同的对象,我们创建一个帮助方法来转换我们的业务对象,或是一个List的业务对象到DataTables.

    由于数据库表中字段可为null,对应.net 2.0以后我们可用Nullable类型来实现,那当我们业务对象类中字段有null时,并需要转换为DataTable时,这个场景产生,你可能用到以下方法:

    /// <summary>
     /// Converts a Generic List into a DataTable
     /// </summary>
     /// <param name="list"></param>
     /// <param name="typ"></param>
     /// <returns></returns>
     private DataTable GetDataTable(IList list, Type typ)
     {
         DataTable dt = new DataTable();
     
         // Get a list of all the properties on the object
         PropertyInfo[] pi = typ.GetProperties();
     
         // Loop through each property, and add it as a column to the datatable
         foreach (PropertyInfo p in pi)
         {
             // The the type of the property
             Type columnType = p.PropertyType;
     
             // We need to check whether the property is NULLABLE
             if (p.PropertyType.IsGenericType && p.PropertyType.GetGenericTypeDefinition() == typeof(Nullable<>))
             {
                 // If it is NULLABLE, then get the underlying type. eg if "Nullable<int>" then this will return just "int"
                 columnType = p.PropertyType.GetGenericArguments()[0];
             }
     
             // Add the column definition to the datatable.
             dt.Columns.Add(new DataColumn(p.Name, columnType));
         }
     
         // For each object in the list, loop through and add the data to the datatable.
         foreach (object obj in list)
         {
             object[] row = new object[pi.Length];
             int i = 0;
     
             foreach (PropertyInfo p in pi)
             {
                 row[i++] = p.GetValue(obj, null);
             }
     
             dt.Rows.Add(row);
         }
     
         return dt;
     }

    上面的代码的关键点:

    • 用 PropertyType.IsGenericType 决定property是否是generic类型
    • 用 ProprtyType.GetGenericTypeDefinition() == typeof(Nullable<>) 检测它是否是一个nullable类型
    • 用 PropertyType.GetGenericArguments() 获取基类型。

    下面让我们来应用一下:

    public class Person
    {
        public string Name { get; set; }
        public DateTime DateOfBirth { get; set; }
        public DateTime? DateOfDeath { get; set; }
    }
     
    public class Example
    {
        public static DataTable RunExample()
        {
            Person edward = new Person() { Name = "Edward", DateOfBirth = new DateTime(1900, 1, 1), DateOfDeath = new DateTime(1990, 10, 15) };
            Person margaret = new Person() { Name = "Margaret", DateOfBirth = new DateTime(1950, 2, 9), DateOfDeath = null };
            Person grant = new Person() { Name = "Grant", DateOfBirth = new DateTime(1975, 6, 13), DateOfDeath = null };
     
            List<Person> people = new List<Person>();
     
            people.Add(edward);
            people.Add(margaret);
            people.Add(grant);
     
            DataTable dt = GetDataTable(people, typeof(Person));
     
            return dt;
        }
    }

    将返回的DataTable像下面的内容:

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  • 原文地址:https://www.cnblogs.com/masonlu/p/10629598.html
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