如何遍历类的所有属性?

时间:2009-02-10 07:44:42

标签: .net vb.net class reflection properties

我上课了。

Public Class Foo
    Private _Name As String
    Public Property Name() As String
        Get
            Return _Name
        End Get
        Set(ByVal value As String)
            _Name = value
        End Set
    End Property

    Private _Age As String
    Public Property Age() As String
        Get
            Return _Age
        End Get
        Set(ByVal value As String)
            _Age = value
        End Set
    End Property

    Private _ContactNumber As String
    Public Property ContactNumber() As String
        Get
            Return _ContactNumber
        End Get
        Set(ByVal value As String)
            _ContactNumber = value
        End Set
    End Property


End Class

我想遍历上面类的属性。 例如;

Public Sub DisplayAll(ByVal Someobject As Foo)
    For Each _Property As something In Someobject.Properties
        Console.WriteLine(_Property.Name & "=" & _Property.value)
    Next
End Sub

7 个答案:

答案 0 :(得分:287)

使用反思:

Type type = obj.GetType();
PropertyInfo[] properties = type.GetProperties();

foreach (PropertyInfo property in properties)
{
    Console.WriteLine("Name: " + property.Name + ", Value: " + property.GetValue(obj, null));
}

编辑:您还可以将BindingFlags值指定为type.GetProperties()

BindingFlags flags = BindingFlags.Public | BindingFlags.Instance;
PropertyInfo[] properties = type.GetProperties(flags);

这会将返回的属性限制为公共实例属性(不包括静态属性,受保护属性等)。

您无需指定BindingFlags.GetProperty,在调用type.InvokeMember()时使用该属性来获取属性的值。

答案 1 :(得分:38)

请注意,如果您正在谈论的对象具有自定义属性模型(例如DataRowViewDataTable等),那么您需要使用TypeDescriptor;好消息是,这对常规课程仍然有效(甚至可以是much quicker than reflection):

foreach(PropertyDescriptor prop in TypeDescriptor.GetProperties(obj)) {
    Console.WriteLine("{0} = {1}", prop.Name, prop.GetValue(obj));
}

这样还可以轻松访问TypeConverter之类的内容进行格式化:

    string fmt = prop.Converter.ConvertToString(prop.GetValue(obj));

答案 2 :(得分:30)

Brannon给出的C#的VB版本:

Public Sub DisplayAll(ByVal Someobject As Foo)
    Dim _type As Type = Someobject.GetType()
    Dim properties() As PropertyInfo = _type.GetProperties()  'line 3
    For Each _property As PropertyInfo In properties
        Console.WriteLine("Name: " + _property.Name + ", Value: " + _property.GetValue(Someobject, Nothing))
    Next
End Sub

使用Binding标志而不是第3行

    Dim flags As BindingFlags = BindingFlags.Public Or BindingFlags.Instance
    Dim properties() As PropertyInfo = _type.GetProperties(flags)

答案 3 :(得分:7)

反思非常“沉重”

也许尝试这个解决方案: // C#

if (item is IEnumerable) {
    foreach (object o in item as IEnumerable) {
            //do function
    }
} else {
    foreach (System.Reflection.PropertyInfo p in obj.GetType().GetProperties())      {
        if (p.CanRead) {
            Console.WriteLine("{0}: {1}", p.Name, p.GetValue(obj,  null)); //possible function
        }
    }
}

“VB.Net

  If TypeOf item Is IEnumerable Then

    For Each o As Object In TryCast(item, IEnumerable)
               'Do Function
     Next
  Else
    For Each p As System.Reflection.PropertyInfo In obj.GetType().GetProperties()
         If p.CanRead Then
               Console.WriteLine("{0}: {1}", p.Name, p.GetValue(obj, Nothing))  'possible function
          End If
      Next
  End If

反射速度减慢+/- 1000 x方法调用的速度,如The Performance of Everyday Things

所示

答案 4 :(得分:1)

private void ResetAllProperties()
    {
        Type type = this.GetType();
        PropertyInfo[] properties = (from c in type.GetProperties()
                                     where c.Name.StartsWith("Doc")
                                     select c).ToArray();
        foreach (PropertyInfo item in properties)
        {
            if (item.PropertyType.FullName == "System.String")
                item.SetValue(this, "", null);
        }
    }

我使用上面的代码块来重置我的Web用户控件对象中的所有字符串属性,这些属性的名称以“Doc”开头。

答案 5 :(得分:1)

这是另一种方法,使用LINQ lambda:

C#:

SomeObject.GetType().GetProperties().ToList().ForEach(x => Console.WriteLine($"{x.Name} = {x.GetValue(SomeObject, null)}"));

VB.NET:

SomeObject.GetType.GetProperties.ToList.ForEach(Sub(x) Console.WriteLine($"{x.Name} = {x.GetValue(SomeObject, Nothing)}"))

答案 6 :(得分:1)

我就是这样做的。

foreach (var fi in typeof(CustomRoles).GetFields())
{
    var propertyName = fi.Name;
}