AttributeCollection 类

定义

public ref class AttributeCollection : System::Collections::ICollection

public class AttributeCollection : System.Collections.ICollection

[System.Runtime.InteropServices.ComVisible(true)]
public class AttributeCollection : System.Collections.ICollection

type AttributeCollection = class
    interface ICollection
    interface IEnumerable

[<System.Runtime.InteropServices.ComVisible(true)>]
type AttributeCollection = class
    interface ICollection
    interface IEnumerable

Public Class AttributeCollection
Implements ICollection

继承

Object

AttributeCollection

属性

ComVisibleAttribute

实现

ICollection IEnumerable

示例

第一个代码示例检查 BrowsableAttribute 是否已在此集合中设置 。 第二个代码示例获取按钮的实际 DescriptionAttribute 值。 这两个示例都需要 button1 在窗体上创建 和 textBox1 。 使用特性时，请验证是否已设置特性，或访问其值。

private:
   void ContainsAttribute()
   {
      // Creates a new collection and assigns it the attributes for button1.
      AttributeCollection^ attributes;
      attributes = TypeDescriptor::GetAttributes( button1 );
      
      // Sets an Attribute to the specific attribute.
      BrowsableAttribute^ myAttribute = BrowsableAttribute::Yes;

      if ( attributes->Contains( myAttribute ) )
      {
         textBox1->Text = "button1 has a browsable attribute.";
      }
      else
      {
         textBox1->Text = "button1 does not have a browsable attribute.";
      }
   }

private void ContainsAttribute() {
    // Creates a new collection and assigns it the attributes for button1.
    AttributeCollection attributes;
    attributes = TypeDescriptor.GetAttributes(button1);

    // Sets an Attribute to the specific attribute.
    BrowsableAttribute myAttribute = BrowsableAttribute.Yes;

    if (attributes.Contains(myAttribute))
       textBox1.Text = "button1 has a browsable attribute.";
    else
       textBox1.Text = "button1 does not have a browsable attribute.";
 }

Private Sub ContainsAttribute()
    ' Creates a new collection and assigns it the attributes for button1.
    Dim attributes As AttributeCollection
    attributes = TypeDescriptor.GetAttributes(button1)
    
    ' Sets an Attribute to the specific attribute.
    Dim myAttribute As BrowsableAttribute = BrowsableAttribute.Yes
    
    If attributes.Contains(myAttribute) Then
        textBox1.Text = "button1 has a browsable attribute."
    Else
        textBox1.Text = "button1 does not have a browsable attribute."
    End If
End Sub

private:
   void GetAttributeValue()
   {
      // Creates a new collection and assigns it the attributes for button1.
      AttributeCollection^ attributes;
      attributes = TypeDescriptor::GetAttributes( button1 );
      
      // Gets the designer attribute from the collection.
      DesignerAttribute^ myDesigner;
      myDesigner = (DesignerAttribute^)(attributes[DesignerAttribute::typeid]);
      
      // Prints the value of the attribute in a text box.
      textBox1->Text = myDesigner->DesignerTypeName;
   }

private void GetAttributeValue() {
    // Creates a new collection and assigns it the attributes for button1.
    AttributeCollection attributes;
    attributes = TypeDescriptor.GetAttributes(button1);

    // Gets the designer attribute from the collection.
    DesignerAttribute myDesigner;
    myDesigner = (DesignerAttribute)attributes[typeof(DesignerAttribute)];

    // Prints the value of the attribute in a text box.
    textBox1.Text = myDesigner.DesignerTypeName;
 }

Private Sub GetAttributeValue()
    ' Creates a new collection and assigns it the attributes for button1.
    Dim attributes As AttributeCollection
    attributes = TypeDescriptor.GetAttributes(button1)
    
    ' Gets the designer attribute from the collection.
    Dim myDesigner As DesignerAttribute
    myDesigner = CType(attributes(GetType(DesignerAttribute)), DesignerAttribute)
    
    ' Prints the value of the attribute in a text box.
    textBox1.Text = myDesigner.DesignerTypeName
End Sub

注解

类 AttributeCollection 是只读的;它不实现添加或删除属性的方法。 必须从此类继承才能实现这些方法。

Count使用 属性可查找集合中存在的属性数。

还可以使用此类的 方法来查询集合中的内容。 Contains调用 方法可验证集合中是否存在指定的属性或特性数组。 Matches调用 方法可验证集合中是否存在指定的属性或属性数组，以及指定的特性的值是否与集合中的值相同。

虽然大多数属性都有默认值，但默认值不是必需的。 如果属性没有默认值， null 则从采用 类型的索引属性返回。 定义自己的属性时，可以通过提供不采用任何参数的构造函数或定义名为“Default”的属性类型的公共静态字段来声明默认值。

构造函数

字段

属性

方法

显式接口实现

扩展方法

适用于

另请参阅

• Attribute
• BrowsableAttribute
• DescriptionAttribute