OrderedDictionary.IsReadOnly 属性

定义

命名空间:

System.Collections.Specialized

程序集:

System.Collections.Specialized.dll

Source:

OrderedDictionary.cs

获取指示 OrderedDictionary 集合是否为只读的值。

public:
 property bool IsReadOnly { bool get(); };

public bool IsReadOnly { get; }

member this.IsReadOnly : bool

Public ReadOnly Property IsReadOnly As Boolean

属性值

Boolean

如果 OrderedDictionary 集合为只读，则为 true；否则为 false。 默认值为 false。

实现

IsReadOnly

示例

下面的代码示例演示了对集合的 OrderedDictionary 修改。 在此示例中， IsReadOnly 属性用于确定是否 OrderedDictionary 可以修改 。 此代码是可在 中查看的较大代码示例的一 OrderedDictionary部分。

// Modifying the OrderedDictionary
if (!myOrderedDictionary->IsReadOnly)
{
    // Insert a new key to the beginning of the OrderedDictionary
    myOrderedDictionary->Insert(0, "insertedKey1", "insertedValue1");

    // Modify the value of the entry with the key "testKey2"
    myOrderedDictionary["testKey2"] = "modifiedValue";

    // Remove the last entry from the OrderedDictionary: "testKey3"
    myOrderedDictionary->RemoveAt(myOrderedDictionary->Count - 1);

    // Remove the "keyToDelete" entry, if it exists
    if (myOrderedDictionary->Contains("keyToDelete"))
    {
        myOrderedDictionary->Remove("keyToDelete");
    }
}

// Modifying the OrderedDictionary
if (!myOrderedDictionary.IsReadOnly)
{
    // Insert a new key to the beginning of the OrderedDictionary
    myOrderedDictionary.Insert(0, "insertedKey1", "insertedValue1");

    // Modify the value of the entry with the key "testKey2"
    myOrderedDictionary["testKey2"] = "modifiedValue";

    // Remove the last entry from the OrderedDictionary: "testKey3"
    myOrderedDictionary.RemoveAt(myOrderedDictionary.Count - 1);

    // Remove the "keyToDelete" entry, if it exists
    if (myOrderedDictionary.Contains("keyToDelete"))
    {
        myOrderedDictionary.Remove("keyToDelete");
    }
}

' Modifying the OrderedDictionary
If Not myOrderedDictionary.IsReadOnly Then

    ' Insert a new key to the beginning of the OrderedDictionary
    myOrderedDictionary.Insert(0, "insertedKey1", "insertedValue1")

    ' Modify the value of the entry with the key "testKey2"
    myOrderedDictionary("testKey2") = "modifiedValue"

    ' Remove the last entry from the OrderedDictionary: "testKey3"
    myOrderedDictionary.RemoveAt(myOrderedDictionary.Count - 1)

    ' Remove the "keyToDelete" entry, if it exists
    If (myOrderedDictionary.Contains("keyToDelete")) Then
        myOrderedDictionary.Remove("keyToDelete")
    End If
End If

注解

在创建只读集合后，该集合不允许添加、移除或修改元素。

只读集合只是一个集合，其中包含阻止修改集合的包装器;因此，如果对基础集合进行了更改，只读集合将反映这些更改。