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[c#.net]遍歷一個對象中所有的屬性和值

through 圖片 ict init 空類 alt style for inf

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>");
}

但是要判斷可空類型的,可空類型的不能使用Property.GetValue(Model,null),如下

        /// <summary>
        /// C#反射遍歷對象屬性
        /// </summary>
        /// <typeparam name="T">對象類型</typeparam>
        /// <param name="model">對象</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(); } }

在我們的應用程序中我們使用類描述我們的業務對象,為我們產生一些報表之類的,那就依賴大量不同的對象,我們創建一個幫助方法來轉換我們的業務對象,或是一個List的業務對象到DataTables.

由於數據庫表中字段可為null,對應.net 2.0以後我們可用Nullable類型來實現,那當我們業務對象類中字段有null時,並需要轉換為DataTable時,這個場景產生,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;
 }

上面的代碼的關鍵點:

  • 用 PropertyType.IsGenericType 決定property是否是generic類型
  • 用 ProprtyType.GetGenericTypeDefinition() == typeof(Nullable<>) 檢測它是否是一個nullable類型
  • 用 PropertyType.GetGenericArguments() 獲取基類型。

下面讓我們來應用一下:

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;
    }
}

將返回的DataTable像下面的內容:

技術分享圖片

[c#.net]遍歷一個對象中所有的屬性和值