IOrderedDictionary Rozhraní
Definice
Důležité
Některé informace platí pro předběžně vydaný produkt, který se může zásadně změnit, než ho výrobce nebo autor vydá. Microsoft neposkytuje žádné záruky, výslovné ani předpokládané, týkající se zde uváděných informací.
Představuje indexovanou kolekci párů klíč/hodnota.
public interface class IOrderedDictionary : System::Collections::IDictionarypublic interface IOrderedDictionary : System.Collections.IDictionarytype IOrderedDictionary = interface
interface ICollection
interface IEnumerable
interface IDictionarytype IOrderedDictionary = interface
interface IDictionary
interface ICollection
interface IEnumerablePublic Interface IOrderedDictionary
Implements IDictionary- Odvozené
- Implementuje
Příklady
Následující příklad kódu ukazuje implementaci jednoduchého IOrderedDictionary na ArrayList základě třídy . Implementovaný soubor IOrderedDictionary ukládá křestní jména jako klíče a příjmení jako hodnoty s přidaným požadavkem, aby každé křestní jméno bylo jedinečné.
#using <System.dll>
using namespace System;
using namespace System::Collections;
using namespace System::Collections::Specialized;
public ref class PeopleEnum : IDictionaryEnumerator
{
private:
// Enumerators are positioned before the first element
// until the first MoveNext() call.
int position;
ArrayList^ _people;
public:
PeopleEnum(ArrayList^ list)
{
this->Reset();
_people = list;
}
virtual bool MoveNext()
{
position++;
return (position < _people->Count);
}
virtual void Reset()
{
position = -1;
}
virtual property Object^ Current
{
Object^ get()
{
try
{
return _people[position];
}
catch (IndexOutOfRangeException^)
{
throw gcnew InvalidOperationException();
}
}
}
virtual property DictionaryEntry Entry
{
DictionaryEntry get()
{
return (DictionaryEntry)(Current);
}
}
virtual property Object^ Key
{
Object^ get()
{
try
{
return ((DictionaryEntry^)_people[position])->Key;
}
catch (IndexOutOfRangeException^)
{
throw gcnew InvalidOperationException();
}
}
}
virtual property Object^ Value
{
Object^ get()
{
try
{
return ((DictionaryEntry^)_people[position])->Value;
}
catch (IndexOutOfRangeException^)
{
throw gcnew InvalidOperationException();
}
}
}
};
public ref class People : IOrderedDictionary
{
private:
ArrayList^ _people;
public:
People(int numItems)
{
_people = gcnew ArrayList(numItems);
}
int IndexOfKey(Object^ key)
{
for (int i = 0; i < _people->Count; i++)
{
if (((DictionaryEntry^)_people[i])->Key == key)
return i;
}
// key not found, return -1.
return -1;
}
virtual property Object^ default[Object^]
{
Object^ get(Object^ key)
{
return ((DictionaryEntry^)_people[IndexOfKey(key)])->Value;
}
void set(Object^ key, Object^ value)
{
_people[IndexOfKey(key)] = gcnew DictionaryEntry(key, value);
}
}
// IOrderedDictionary Members
virtual IDictionaryEnumerator^ GetEnumerator()
{
return gcnew PeopleEnum(_people);
}
virtual void Insert(int index, Object^ key, Object^ value)
{
if (IndexOfKey(key) != -1)
{
throw gcnew ArgumentException("An element with the same key already exists in the collection.");
}
_people->Insert(index, gcnew DictionaryEntry(key, value));
}
virtual void RemoveAt(int index)
{
_people->RemoveAt(index);
}
virtual property Object^ default[int]
{
Object^ get(int index)
{
return ((DictionaryEntry^)_people[index])->Value;
}
void set(int index, Object^ value)
{
Object^ key = ((DictionaryEntry^)_people[index])->Key;
_people[index] = gcnew DictionaryEntry(key, value);
}
}
// IDictionary Members
virtual void Add(Object^ key, Object^ value)
{
if (IndexOfKey(key) != -1)
{
throw gcnew ArgumentException("An element with the same key already exists in the collection.");
}
_people->Add(gcnew DictionaryEntry(key, value));
}
virtual void Clear()
{
_people->Clear();
}
virtual bool Contains(Object^ key)
{
if (IndexOfKey(key) == -1)
{
return false;
}
else
{
return true;
}
}
virtual property bool IsFixedSize
{
bool get()
{
return false;
}
}
virtual property bool IsReadOnly
{
bool get()
{
return false;
}
}
virtual property ICollection^ Keys
{
ICollection^ get()
{
ArrayList^ KeyCollection = gcnew ArrayList(_people->Count);
for (int i = 0; i < _people->Count; i++)
{
KeyCollection->Add( ((DictionaryEntry^)_people[i])->Key );
}
return KeyCollection;
}
}
virtual void Remove(Object^ key)
{
_people->RemoveAt(IndexOfKey(key));
}
virtual property ICollection^ Values
{
ICollection ^get()
{
ArrayList^ ValueCollection = gcnew ArrayList(_people->Count);
for (int i = 0; i < _people->Count; i++)
{
ValueCollection->Add( ((DictionaryEntry^)_people[i])->Value );
}
return ValueCollection;
}
}
// ICollection Members
virtual void CopyTo(Array^ array, int index)
{
_people->CopyTo(array, index);
}
virtual property int Count
{
int get()
{
return _people->Count;
}
}
virtual property bool IsSynchronized
{
bool get()
{
return _people->IsSynchronized;
}
}
virtual property Object^ SyncRoot
{
Object^ get()
{
return _people->SyncRoot;
}
}
// IEnumerable Members
virtual IEnumerator^ IfcGetEnumerator() = IEnumerable::GetEnumerator
{
return (IEnumerator^) gcnew PeopleEnum(_people);
}
};
class App
{
public:
static void Main()
{
People^ peopleCollection = gcnew People(3);
peopleCollection->Add("John", "Smith");
peopleCollection->Add("Jim", "Johnson");
peopleCollection->Add("Sue", "Rabon");
Console::WriteLine("Displaying the entries in peopleCollection:");
for each (DictionaryEntry^ de in peopleCollection)
{
Console::WriteLine("{0} {1}", de->Key, de->Value);
}
Console::WriteLine();
Console::WriteLine("Displaying the entries in the modified peopleCollection:");
peopleCollection["Jim"] = "Jackson";
peopleCollection->Remove("Sue");
peopleCollection->Insert(0, "Fred", "Anderson");
for each (DictionaryEntry^ de in peopleCollection)
{
Console::WriteLine("{0} {1}", de->Key, de->Value);
}
}
};
int main()
{
App::Main();
}
/* This code produces output similar to the following:
*
* Displaying the entries in peopleCollection:
* John Smith
* Jim Johnson
* Sue Rabon
*
* Displaying the entries in the modified peopleCollection:
* Fred Anderson
* John Smith
* Jim Jackson
*/
using System;
using System.Collections;
using System.Collections.Specialized;
public class People : IOrderedDictionary
{
private ArrayList _people;
public People(int numItems)
{
_people = new ArrayList(numItems);
}
public int IndexOfKey(object key)
{
for (int i = 0; i < _people.Count; i++)
{
if (((DictionaryEntry)_people[i]).Key == key)
return i;
}
// key not found, return -1.
return -1;
}
public object this[object key]
{
get
{
return ((DictionaryEntry)_people[IndexOfKey(key)]).Value;
}
set
{
_people[IndexOfKey(key)] = new DictionaryEntry(key, value);
}
}
// IOrderedDictionary Members
public IDictionaryEnumerator GetEnumerator()
{
return new PeopleEnum(_people);
}
public void Insert(int index, object key, object value)
{
if (IndexOfKey(key) != -1)
{
throw new ArgumentException("An element with the same key already exists in the collection.");
}
_people.Insert(index, new DictionaryEntry(key, value));
}
public void RemoveAt(int index)
{
_people.RemoveAt(index);
}
public object this[int index]
{
get
{
return ((DictionaryEntry)_people[index]).Value;
}
set
{
object key = ((DictionaryEntry)_people[index]).Key;
_people[index] = new DictionaryEntry(key, value);
}
}
// IDictionary Members
public void Add(object key, object value)
{
if (IndexOfKey(key) != -1)
{
throw new ArgumentException("An element with the same key already exists in the collection.");
}
_people.Add(new DictionaryEntry(key, value));
}
public void Clear()
{
_people.Clear();
}
public bool Contains(object key)
{
if (IndexOfKey(key) == -1)
{
return false;
}
else
{
return true;
}
}
public bool IsFixedSize
{
get
{
return false;
}
}
public bool IsReadOnly
{
get
{
return false;
}
}
public ICollection Keys
{
get
{
ArrayList KeyCollection = new ArrayList(_people.Count);
for (int i = 0; i < _people.Count; i++)
{
KeyCollection.Add( ((DictionaryEntry)_people[i]).Key );
}
return KeyCollection;
}
}
public void Remove(object key)
{
_people.RemoveAt(IndexOfKey(key));
}
public ICollection Values
{
get
{
ArrayList ValueCollection = new ArrayList(_people.Count);
for (int i = 0; i < _people.Count; i++)
{
ValueCollection.Add( ((DictionaryEntry)_people[i]).Value );
}
return ValueCollection;
}
}
// ICollection Members
public void CopyTo(Array array, int index)
{
_people.CopyTo(array, index);
}
public int Count
{
get
{
return _people.Count;
}
}
public bool IsSynchronized
{
get
{
return _people.IsSynchronized;
}
}
public object SyncRoot
{
get
{
return _people.SyncRoot;
}
}
// IEnumerable Members
IEnumerator IEnumerable.GetEnumerator()
{
return new PeopleEnum(_people);
}
}
public class PeopleEnum : IDictionaryEnumerator
{
public ArrayList _people;
// Enumerators are positioned before the first element
// until the first MoveNext() call.
int position = -1;
public PeopleEnum(ArrayList list)
{
_people = list;
}
public bool MoveNext()
{
position++;
return (position < _people.Count);
}
public void Reset()
{
position = -1;
}
public object Current
{
get
{
try
{
return _people[position];
}
catch (IndexOutOfRangeException)
{
throw new InvalidOperationException();
}
}
}
public DictionaryEntry Entry
{
get
{
return (DictionaryEntry)Current;
}
}
public object Key
{
get
{
try
{
return ((DictionaryEntry)_people[position]).Key;
}
catch (IndexOutOfRangeException)
{
throw new InvalidOperationException();
}
}
}
public object Value
{
get
{
try
{
return ((DictionaryEntry)_people[position]).Value;
}
catch (IndexOutOfRangeException)
{
throw new InvalidOperationException();
}
}
}
}
class App
{
static void Main()
{
People peopleCollection = new People(3);
peopleCollection.Add("John", "Smith");
peopleCollection.Add("Jim", "Johnson");
peopleCollection.Add("Sue", "Rabon");
Console.WriteLine("Displaying the entries in peopleCollection:");
foreach (DictionaryEntry de in peopleCollection)
{
Console.WriteLine("{0} {1}", de.Key, de.Value);
}
Console.WriteLine();
Console.WriteLine("Displaying the entries in the modified peopleCollection:");
peopleCollection["Jim"] = "Jackson";
peopleCollection.Remove("Sue");
peopleCollection.Insert(0, "Fred", "Anderson");
foreach (DictionaryEntry de in peopleCollection)
{
Console.WriteLine("{0} {1}", de.Key, de.Value);
}
}
}
/* This code produces output similar to the following:
*
* Displaying the entries in peopleCollection:
* John Smith
* Jim Johnson
* Sue Rabon
*
* Displaying the entries in the modified peopleCollection:
* Fred Anderson
* John Smith
* Jim Jackson
*/
Imports System.Collections
Imports System.Collections.Specialized
Public Class People
Implements IOrderedDictionary
Private _people As ArrayList
Public Sub New(ByVal numItems As Integer)
_people = New ArrayList(numItems)
End Sub
Public Function IndexOfKey(ByVal key As Object) As Integer
Dim i As Integer
For i = 0 To _people.Count - 1
If CType(_people(i), DictionaryEntry).Key = key Then
Return i
End If
Next i
' key not found, return -1.
Return -1
End Function
' IOrderedDictionary Members
Public Function GetEnumerator() As IDictionaryEnumerator _
Implements IOrderedDictionary.GetEnumerator
Return New PeopleEnum(_people)
End Function
Public Sub Insert(ByVal index As Integer, ByVal key As Object, _
ByVal value As Object) Implements IOrderedDictionary.Insert
If Not IndexOfKey(key) = -1 Then
Throw New ArgumentException("An element with the same key already exists in the collection.")
End If
_people.Insert(index, New DictionaryEntry(key, value))
End Sub
Public Sub RemoveAt(ByVal index As Integer) _
Implements IOrderedDictionary.RemoveAt
_people.RemoveAt(index)
End Sub
Public Property Item(ByVal index As Integer) As Object _
Implements IOrderedDictionary.Item
Get
Return CType(_people(index), DictionaryEntry).Value
End Get
Set(ByVal value As Object)
Dim key As Object = CType(_people(index), DictionaryEntry).Key
_people(index) = New DictionaryEntry(key, value)
End Set
End Property
' IDictionary Members
Public Function IDictionaryGetEnumerator() As IDictionaryEnumerator _
Implements IDictionary.GetEnumerator
Return New PeopleEnum(_people)
End Function
Public Property Item(ByVal key As Object) As Object _
Implements IDictionary.Item
Get
Return CType(_people(IndexOfKey(key)), DictionaryEntry).Value
End Get
Set(ByVal value)
_people(IndexOfKey(key)) = New DictionaryEntry(key, value)
End Set
End Property
Public Sub Add(ByVal key As Object, ByVal value As Object) _
Implements IDictionary.Add
If Not IndexOfKey(key) = -1 Then
Throw New ArgumentException("An element with the same key already exists in the collection.")
End If
_people.Add(New DictionaryEntry(key, value))
End Sub
Public Sub Clear() Implements IDictionary.Clear
_people.Clear()
End Sub
Public Function Contains(ByVal key As Object) As Boolean _
Implements IDictionary.Contains
If IndexOfKey(key) = -1 Then
Return False
Else
Return True
End If
End Function
Public ReadOnly Property IsFixedSize() As Boolean _
Implements IDictionary.IsFixedSize
Get
Return False
End Get
End Property
Public ReadOnly Property IsReadOnly() As Boolean _
Implements IDictionary.IsReadOnly
Get
Return False
End Get
End Property
Public ReadOnly Property Keys() As ICollection _
Implements IDictionary.Keys
Get
Dim KeyCollection As ArrayList = New ArrayList(_people.Count)
Dim i As Integer
For i = 0 To _people.Count - 1
KeyCollection.Add( CType(_people(i), DictionaryEntry).Key )
Next i
Return KeyCollection
End Get
End Property
Public Sub Remove(ByVal key As Object) _
Implements IDictionary.Remove
_people.RemoveAt(IndexOfKey(key))
End Sub
Public ReadOnly Property Values() As ICollection _
Implements IDictionary.Values
Get
Dim ValueCollection As ArrayList = New ArrayList(_people.Count)
Dim i As Integer
For i = 0 To _people.Count - 1
ValueCollection.Add( CType(_people(i), DictionaryEntry).Value )
Next i
Return ValueCollection
End Get
End Property
' ICollection Members
Public Sub CopyTo(ByVal array As Array, ByVal index As Integer) _
Implements ICollection.CopyTo
_people.CopyTo(Array, index)
End Sub
Public ReadOnly Property Count() As Integer _
Implements ICollection.Count
Get
Return _people.Count
End Get
End Property
Public ReadOnly Property IsSynchronized() As Boolean _
Implements ICollection.IsSynchronized
Get
Return _people.IsSynchronized
End Get
End Property
Public ReadOnly Property SyncRoot() As Object _
Implements ICollection.SyncRoot
Get
Return _people.SyncRoot
End Get
End Property
' IEnumerable Members
Public Function IEnumerableGetEnumerator() As IEnumerator _
Implements IEnumerable.GetEnumerator
Return New PeopleEnum(_people)
End Function
End Class
Public Class PeopleEnum
Implements IDictionaryEnumerator
Public _people As ArrayList
' Enumerators are positioned before the first element
' until the first MoveNext() call.
Dim position As Integer = -1
Public Sub New(ByVal list As ArrayList)
_people = list
End Sub
Public Function MoveNext() As Boolean _
Implements IEnumerator.MoveNext
position = position + 1
Return (position < _people.Count)
End Function
Public Sub Reset() _
Implements IEnumerator.Reset
position = -1
End Sub
Public ReadOnly Property Current() As Object _
Implements IEnumerator.Current
Get
Try
Return _people(position)
Catch e As IndexOutOfRangeException
Throw New InvalidOperationException()
End Try
End Get
End Property
Public ReadOnly Property Entry() As DictionaryEntry _
Implements IDictionaryEnumerator.Entry
Get
Return CType(Current, DictionaryEntry)
End Get
End Property
Public ReadOnly Property Key() As Object _
Implements IDictionaryEnumerator.Key
Get
Try
Return CType(_people(position), DictionaryEntry).Key
Catch e As IndexOutOfRangeException
Throw New InvalidOperationException()
End Try
End Get
End Property
Public ReadOnly Property Value() As Object _
Implements IDictionaryEnumerator.Value
Get
Try
Return CType(_people(position), DictionaryEntry).Value
Catch e As IndexOutOfRangeException
Throw New InvalidOperationException()
End Try
End Get
End Property
End Class
Class App
Shared Sub Main()
Dim peopleCollection As People = New People(3)
peopleCollection.Add("John", "Smith")
peopleCollection.Add("Jim", "Johnson")
peopleCollection.Add("Sue", "Rabon")
Console.WriteLine("Displaying the entries in peopleCollection:")
Dim de As DictionaryEntry
For Each de In peopleCollection
Console.WriteLine("{0} {1}", de.Key, de.Value)
Next
Console.WriteLine()
Console.WriteLine("Displaying the entries in the modified peopleCollection:")
'peopleCollection("Jim") = "Jackson"
peopleCollection.Remove("Sue")
peopleCollection.Insert(0, "Fred", "Anderson")
For Each de In peopleCollection
Console.WriteLine("{0} {1}", de.Key, de.Value)
Next
End Sub
End Class
' This code produces output similar to the following:
'
' Displaying the entries in peopleCollection:
' John Smith
' Jim Johnson
' Sue Rabon
'
' Displaying the entries in the modified peopleCollection:
' Fred Anderson
' John Smith
' Jim Jackson
Poznámky
IOrderedDictionary k elementům je možné přistupovat buď pomocí klíče, nebo pomocí indexu.
Každý prvek je pár klíč-hodnota uložený ve struktuře DictionaryEntry .
Každý pár musí mít jedinečný klíč, který není null, ale hodnota může být null a nemusí být jedinečná. Rozhraní IOrderedDictionary umožňuje výčet obsažených klíčů a hodnot, ale neznamená to žádné konkrétní pořadí řazení.
Příkaz foreach jazyka C# (For Each v jazyce Visual Basic) vrátí objekt typu prvků v kolekci. Vzhledem k tomu, že každý prvek objektu IDictionary je pár klíč/hodnota, typ prvku není typem klíče ani typem hodnoty. Místo toho je typ elementu , jak ukazuje DictionaryEntrynásledující příklad.
for each (DictionaryEntry de in myOrderedDictionary)
{
//...
}
foreach (DictionaryEntry de in myOrderedDictionary)
{
//...
}
For Each de In myOrderedDictionary
'...
Next
Příkaz foreach je obálka kolem enumerátoru, která umožňuje pouze čtení z kolekce, nikoli zápis do kolekce.
Poznámky pro implementátory
Implementovat třídu musí mít prostředky k porovnání klíčů.
Vlastnosti
| Count |
Získá počet elementů obsažených v objektu ICollection. (Zděděno od ICollection) |
| IsFixedSize |
Získá hodnotu označující, zda IDictionary objekt má pevnou velikost. (Zděděno od IDictionary) |
| IsReadOnly |
Získá hodnotu označující, zda IDictionary je objekt jen pro čtení. (Zděděno od IDictionary) |
| IsSynchronized |
Získá hodnotu označující, zda přístup k objektu ICollection je synchronizován (bezpečný pro přístup z více vláken). (Zděděno od ICollection) |
| Item[Int32] |
Získá nebo nastaví prvek u zadaného indexu. |
| Item[Object] |
Získá nebo nastaví prvek se zadaným klíčem. (Zděděno od IDictionary) |
| Keys |
ICollection Získá objekt obsahující klíče objektuIDictionary. (Zděděno od IDictionary) |
| SyncRoot |
Získá objekt, který lze použít k synchronizaci přístupu k .ICollection (Zděděno od ICollection) |
| Values |
ICollection Získá objekt obsahující hodnoty v objektuIDictionary. (Zděděno od IDictionary) |
Metody
| Add(Object, Object) |
Přidá prvek se zadaným klíčem a hodnotou do objektu IDictionary . (Zděděno od IDictionary) |
| Clear() |
Odebere z objektu IDictionary všechny prvky. (Zděděno od IDictionary) |
| Contains(Object) |
Určuje, zda IDictionary objekt obsahuje prvek se zadaným klíčem. (Zděděno od IDictionary) |
| CopyTo(Array, Int32) |
Zkopíruje prvky objektu ICollectionArraydo , počínaje konkrétním Array indexem. (Zděděno od ICollection) |
| GetEnumerator() |
Vrátí enumerátor, který prochází kolekcí IOrderedDictionary . |
| Insert(Int32, Object, Object) |
Vloží dvojici klíč/hodnota do kolekce v zadaném indexu. |
| Remove(Object) |
Odebere prvek se zadaným klíčem z objektu IDictionary . (Zděděno od IDictionary) |
| RemoveAt(Int32) |
Odebere prvek v zadaném indexu. |
Metody rozšíření
| Cast<TResult>(IEnumerable) |
Přetypuje prvky objektu na IEnumerable zadaný typ. |
| OfType<TResult>(IEnumerable) |
Filtruje prvky objektu IEnumerable na základě zadaného typu. |
| AsParallel(IEnumerable) |
Umožňuje paralelizaci dotazu. |
| AsQueryable(IEnumerable) |
Převede objekt na IEnumerableIQueryable. |
Platí pro
Viz také
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