IDictionary.Keys 属性

定义

命名空间:

System.Collections

程序集:

System.Runtime.dll

获取 ICollection 对象，它包含 IDictionary 对象的键。

public:
 property System::Collections::ICollection ^ Keys { System::Collections::ICollection ^ get(); };

public System.Collections.ICollection Keys { get; }

member this.Keys : System.Collections.ICollection

Public ReadOnly Property Keys As ICollection

属性值

ICollection

ICollection 对象，它包含 IDictionary 对象的键。

示例

下面的代码示例演示如何实现 Keys 属性。 此代码示例是为 IDictionary 类提供的一个更大示例的一部分。

public:
    virtual property ICollection^ Keys
    {
        ICollection^ get()
        {
            // Return an array where each item is a key.
            array<Object^>^ keys = gcnew array<Object^>(itemsInUse);
            for (int i = 0; i < itemsInUse; i++)
            {
                keys[i] = items[i]->Key;
            }
            return keys;
        }
    }

public ICollection Keys
{
    get
    {
        // Return an array where each item is a key.
        Object[] keys = new Object[ItemsInUse];
        for (Int32 n = 0; n < ItemsInUse; n++)
            keys[n] = items[n].Key;
        return keys;
    }
}

Public ReadOnly Property Keys() As ICollection Implements IDictionary.Keys
    Get

        ' Return an array where each item is a key.
        ' Note: Declaring keyArray() to have a size of ItemsInUse - 1
        '       ensures that the array is properly sized, in VB.NET
        '       declaring an array of size N creates an array with
        '       0 through N elements, including N, as opposed to N - 1
        '       which is the default behavior in C# and C++.
        Dim keyArray() As Object = New Object(ItemsInUse - 1) {}
        Dim n As Integer
        For n = 0 To ItemsInUse - 1
            keyArray(n) = items(n).Key
        Next n

        Return keyArray
    End Get
End Property

注解

返回ICollection的对象中键的顺序未指定，但保证与 属性返回Values的 中的ICollection相应值的顺序相同。

另请参阅

• ICollection