IDictionary.Add(Object, Object) 方法

定義

將隨附有索引鍵和值的項目加入至 IDictionary 物件。Adds an element with the provided key and value to the IDictionary object.

public:
 void Add(System::Object ^ key, System::Object ^ value);
public void Add (object key, object value);
public void Add (object key, object? value);
abstract member Add : obj * obj -> unit
Public Sub Add (key As Object, value As Object)

參數

key
Object

Object,用做要加入之項目的索引鍵。The Object to use as the key of the element to add.

value
Object

Object,用做要加入之項目的值。The Object to use as the value of the element to add.

例外狀況

keynullkey is null.

具有相同索引鍵的項目已經存在 IDictionary 物件中。An element with the same key already exists in the IDictionary object.

IDictionary 為唯讀。The IDictionary is read-only.

-或--or- IDictionary 具有固定的大小。The IDictionary has a fixed size.

範例

下列程式碼範例示範如何執行 Add 方法。The following code example demonstrates how to implement the Add method. 這個程式碼範例是針對類別提供之較大範例的一部分 IDictionaryThis code example is part of a larger example provided for the IDictionary class.

public:
    virtual void Add(Object^ key, Object^ value)
    {
        // Add the new key/value pair even if this key already exists
        // in the dictionary.
        if (itemsInUse == items->Length)
        {
            throw gcnew InvalidOperationException
                ("The dictionary cannot hold any more items.");
        }
        items[itemsInUse++] = gcnew DictionaryEntry(key, value);
    }
public void Add(object key, object value)
{
    // Add the new key/value pair even if this key already exists in the dictionary.
    if (ItemsInUse == items.Length)
        throw new InvalidOperationException("The dictionary cannot hold any more items.");
    items[ItemsInUse++] = new DictionaryEntry(key, value);
}
Public Sub Add(ByVal key As Object, ByVal value As Object) Implements IDictionary.Add

    ' Add the new key/value pair even if this key already exists in the dictionary.
    If ItemsInUse = items.Length Then
        Throw New InvalidOperationException("The dictionary cannot hold any more items.")
    End If
    items(ItemsInUse) = New DictionaryEntry(key, value)
    ItemsInUse = ItemsInUse + 1
End Sub

備註

您也可以使用 Item[] 屬性來加入新的元素,方法是設定不存在於字典中的索引鍵值 (例如 myCollection["myNonexistentKey"] = myValue) 。You can also use the Item[] property to add new elements by setting the value of a key that does not exist in the dictionary (for example, myCollection["myNonexistentKey"] = myValue). 但是,如果指定的索引鍵已經存在於字典中,則設定 Item[] 屬性會覆寫舊的值。However, if the specified key already exists in the dictionary, setting the Item[] property overwrites the old value. 相反地,此 Add 方法不會修改現有的元素。In contrast, the Add method does not modify existing elements.

無論是否允許索引鍵,都可能會有不同的執行方式 nullImplementations can vary in whether they allow the key to be null.

適用於

另請參閱