DictionaryBase.GetEnumerator メソッド
アセンブリ: mscorlib (mscorlib.dll 内)

Dim instance As DictionaryBase Dim returnValue As IDictionaryEnumerator returnValue = instance.GetEnumerator
public IDictionaryEnumerator GetEnumerator ()
public: virtual IDictionaryEnumerator^ GetEnumerator () sealed
public final IDictionaryEnumerator GetEnumerator ()
public final function GetEnumerator () : IDictionaryEnumerator
DictionaryBase インスタンスの IDictionaryEnumerator。

C# 言語の foreach ステートメント (Visual Basic の場合は for each) を使用することで列挙子の複雑さを回避できます。したがって、列挙子を直接操作するのではなく、foreach の使用をお勧めします。
列挙子を使用すると、コレクション内のデータを読み取ることができますが、基になるコレクションを変更することはできません。
初期状態では、列挙子はコレクションの最初の要素の前に位置しています。Reset を実行した場合も、列挙子はこの位置に戻されます。この位置で、Current が未定義です。したがって、Current の値を読み取る前に、MoveNext を呼び出して、コレクションの最初の要素に列挙子を進める必要があります。
Current は、MoveNext または Reset が呼び出されるまでは同じオブジェクトを返します。MoveNext は、Current を次の要素に設定します。
MoveNext がコレクションの末尾を過ぎると、列挙子はコレクションの最後の要素の後ろに配置され、MoveNext は false を返します。列挙子がこの位置にある場合、以降、MoveNext を呼び出しても false が返されます。MoveNext への最後の呼び出しで false が返された場合は、Current が未定義です。Current をコレクションの最初の要素に再び設定するには、Reset を呼び出してから、MoveNext を呼び出します。
コレクションが変更されない限り、列挙子は有効なままです。要素の追加、変更、削除などの変更がコレクションに対して実行されると、列挙子は回復不可能な無効状態になり、動作は未定義になります。
列挙子はコレクションへの排他アクセス権を持たないため、コレクションの列挙処理は、本質的にはスレッド セーフな処理ではありません。すべての列挙処理が終わるまでコレクションをロックすることにより、列挙処理でのスレッド セーフを確保できます。コレクションに対し複数のスレッドがアクセスして読み取りや書き込みを行うことができるようにするには、独自に同期化を実装する必要があります。

DictionaryBase クラスを実装し、その実装を使用して、Length が 5 文字以下の String キーと値のディクショナリを作成する方法については、次のコード例を参照してください。
Imports System Imports System.Collections Public Class ShortStringDictionary Inherits DictionaryBase Default Public Property Item(key As String) As String Get Return CType(Dictionary(key), String) End Get Set Dictionary(key) = value End Set End Property Public ReadOnly Property Keys() As ICollection Get Return Dictionary.Keys End Get End Property Public ReadOnly Property Values() As ICollection Get Return Dictionary.Values End Get End Property Public Sub Add(key As String, value As String) Dictionary.Add(key, value) End Sub 'Add Public Function Contains(key As String) As Boolean Return Dictionary.Contains(key) End Function 'Contains Public Sub Remove(key As String) Dictionary.Remove(key) End Sub 'Remove Protected Overrides Sub OnInsert(key As Object, value As Object) If Not GetType(System.String).IsAssignableFrom(key.GetType()) Then Throw New ArgumentException("key must be of type String.", "key") Else Dim strKey As String = CType(key, String) If strKey.Length > 5 Then Throw New ArgumentException("key must be no more than 5 characters in length.", "key") End If End If If Not GetType(System.String).IsAssignableFrom(value.GetType()) Then Throw New ArgumentException("value must be of type String.", "value") Else Dim strValue As String = CType(value, String) If strValue.Length > 5 Then Throw New ArgumentException("value must be no more than 5 characters in length.", "value") End If End If End Sub 'OnInsert Protected Overrides Sub OnRemove(key As Object, value As Object) If Not GetType(System.String).IsAssignableFrom(key.GetType()) Then Throw New ArgumentException("key must be of type String.", "key") Else Dim strKey As String = CType(key, String) If strKey.Length > 5 Then Throw New ArgumentException("key must be no more than 5 characters in length.", "key") End If End If End Sub 'OnRemove Protected Overrides Sub OnSet(key As Object, oldValue As Object, newValue As Object) If Not GetType(System.String).IsAssignableFrom(key.GetType()) Then Throw New ArgumentException("key must be of type String.", "key") Else Dim strKey As String = CType(key, String) If strKey.Length > 5 Then Throw New ArgumentException("key must be no more than 5 characters in length.", "key") End If End If If Not GetType(System.String).IsAssignableFrom(newValue.GetType()) Then Throw New ArgumentException("newValue must be of type String.", "newValue") Else Dim strValue As String = CType(newValue, String) If strValue.Length > 5 Then Throw New ArgumentException("newValue must be no more than 5 characters in length.", "newValue") End If End If End Sub 'OnSet Protected Overrides Sub OnValidate(key As Object, value As Object) If Not GetType(System.String).IsAssignableFrom(key.GetType()) Then Throw New ArgumentException("key must be of type String.", "key") Else Dim strKey As String = CType(key, String) If strKey.Length > 5 Then Throw New ArgumentException("key must be no more than 5 characters in length.", "key") End If End If If Not GetType(System.String).IsAssignableFrom(value.GetType()) Then Throw New ArgumentException("value must be of type String.", "value") Else Dim strValue As String = CType(value, String) If strValue.Length > 5 Then Throw New ArgumentException("value must be no more than 5 characters in length.", "value") End If End If End Sub 'OnValidate End Class 'ShortStringDictionary Public Class SamplesDictionaryBase Public Shared Sub Main() ' Creates and initializes a new DictionaryBase. Dim mySSC As New ShortStringDictionary() ' Adds elements to the collection. mySSC.Add("One", "a") mySSC.Add("Two", "ab") mySSC.Add("Three", "abc") mySSC.Add("Four", "abcd") mySSC.Add("Five", "abcde") ' Display the contents of the collection using For Each. This is the preferred method. Console.WriteLine("Contents of the collection (using For Each):") PrintKeysAndValues1(mySSC) ' Display the contents of the collection using the enumerator. Console.WriteLine("Contents of the collection (using enumerator):") PrintKeysAndValues2(mySSC) ' Display the contents of the collection using the Keys property and the Item property. Console.WriteLine("Initial contents of the collection (using Keys and Item):") PrintKeysAndValues3(mySSC) ' Tries to add a value that is too long. Try mySSC.Add("Ten", "abcdefghij") Catch e As ArgumentException Console.WriteLine(e.ToString()) End Try ' Tries to add a key that is too long. Try mySSC.Add("Eleven", "ijk") Catch e As ArgumentException Console.WriteLine(e.ToString()) End Try Console.WriteLine() ' Searches the collection with Contains. Console.WriteLine("Contains ""Three"": {0}", mySSC.Contains("Three")) Console.WriteLine("Contains ""Twelve"": {0}", mySSC.Contains("Twelve")) Console.WriteLine() ' Removes an element from the collection. mySSC.Remove("Two") ' Displays the contents of the collection. Console.WriteLine("After removing ""Two"":") PrintKeysAndValues1(mySSC) End Sub 'Main ' Uses the For Each statement which hides the complexity of the enumerator. ' NOTE: The For Each statement is the preferred way of enumerating the contents of a collection. Public Shared Sub PrintKeysAndValues1(myCol As ShortStringDictionary) Dim myDE As DictionaryEntry For Each myDE In myCol Console.WriteLine(" {0,-5} : {1}", myDE.Key, myDE.Value) Next myDE Console.WriteLine() End Sub 'PrintKeysAndValues1 ' Uses the enumerator. ' NOTE: The For Each statement is the preferred way of enumerating the contents of a collection. Public Shared Sub PrintKeysAndValues2(myCol As ShortStringDictionary) Dim myDE As DictionaryEntry Dim myEnumerator As System.Collections.IEnumerator = myCol.GetEnumerator() While myEnumerator.MoveNext() If Not (myEnumerator.Current Is Nothing) Then myDE = CType(myEnumerator.Current, DictionaryEntry) Console.WriteLine(" {0,-5} : {1}", myDE.Key, myDE.Value) End If End While Console.WriteLine() End Sub 'PrintKeysAndValues2 ' Uses the Keys property and the Item property. Public Shared Sub PrintKeysAndValues3(myCol As ShortStringDictionary) Dim myKeys As ICollection = myCol.Keys Dim k As String For Each k In myKeys Console.WriteLine(" {0,-5} : {1}", k, myCol(k)) Next k Console.WriteLine() End Sub 'PrintKeysAndValues3 End Class 'SamplesDictionaryBase 'This code produces the following output. ' 'Contents of the collection (using For Each): ' Three : abc ' Five : abcde ' Two : ab ' One : a ' Four : abcd ' 'Contents of the collection (using enumerator): ' Three : abc ' Five : abcde ' Two : ab ' One : a ' Four : abcd ' 'Initial contents of the collection (using Keys and Item): ' Three : abc ' Five : abcde ' Two : ab ' One : a ' Four : abcd ' 'System.ArgumentException: value must be no more than 5 characters in length. 'Parameter name: value ' at ShortStringDictionary.OnValidate(Object key, Object value) ' at System.Collections.DictionaryBase.System.Collections.IDictionary.Add(Object key, Object value) ' at SamplesDictionaryBase.Main() 'System.ArgumentException: key must be no more than 5 characters in length. 'Parameter name: key ' at ShortStringDictionary.OnValidate(Object key, Object value) ' at System.Collections.DictionaryBase.System.Collections.IDictionary.Add(Object key, Object value) ' at SamplesDictionaryBase.Main() ' 'Contains "Three": True 'Contains "Twelve": False ' 'After removing "Two": ' Three : abc ' Five : abcde ' One : a ' Four : abcd
using System; using System.Collections; public class ShortStringDictionary : DictionaryBase { public String this[ String key ] { get { return( (String) Dictionary[key] ); } set { Dictionary[key] = value; } } public ICollection Keys { get { return( Dictionary.Keys ); } } public ICollection Values { get { return( Dictionary.Values ); } } public void Add( String key, String value ) { Dictionary.Add( key, value ); } public bool Contains( String key ) { return( Dictionary.Contains( key ) ); } public void Remove( String key ) { Dictionary.Remove( key ); } protected override void OnInsert( Object key, Object value ) { if ( key.GetType() != typeof(System.String) ) throw new ArgumentException( "key must be of type String.", "key" ); else { String strKey = (String) key; if ( strKey.Length > 5 ) throw new ArgumentException( "key must be no more than 5 characters in length.", "key" ); } if ( value.GetType() != typeof(System.String) ) throw new ArgumentException( "value must be of type String.", "value" ); else { String strValue = (String) value; if ( strValue.Length > 5 ) throw new ArgumentException( "value must be no more than 5 characters in length.", "value" ); } } protected override void OnRemove( Object key, Object value ) { if ( key.GetType() != typeof(System.String) ) throw new ArgumentException( "key must be of type String.", "key" ); else { String strKey = (String) key; if ( strKey.Length > 5 ) throw new ArgumentException( "key must be no more than 5 characters in length.", "key" ); } } protected override void OnSet( Object key, Object oldValue, Object newValue ) { if ( key.GetType() != typeof(System.String) ) throw new ArgumentException( "key must be of type String.", "key" ); else { String strKey = (String) key; if ( strKey.Length > 5 ) throw new ArgumentException( "key must be no more than 5 characters in length.", "key" ); } if ( newValue.GetType() != typeof(System.String) ) throw new ArgumentException( "newValue must be of type String.", "newValue" ); else { String strValue = (String) newValue; if ( strValue.Length > 5 ) throw new ArgumentException( "newValue must be no more than 5 characters in length.", "newValue" ); } } protected override void OnValidate( Object key, Object value ) { if ( key.GetType() != typeof(System.String) ) throw new ArgumentException( "key must be of type String.", "key" ); else { String strKey = (String) key; if ( strKey.Length > 5 ) throw new ArgumentException( "key must be no more than 5 characters in length.", "key" ); } if ( value.GetType() != typeof(System.String) ) throw new ArgumentException( "value must be of type String.", "value" ); else { String strValue = (String) value; if ( strValue.Length > 5 ) throw new ArgumentException( "value must be no more than 5 characters in length.", "value" ); } } } public class SamplesDictionaryBase { public static void Main() { // Creates and initializes a new DictionaryBase. ShortStringDictionary mySSC = new ShortStringDictionary(); // Adds elements to the collection. mySSC.Add( "One", "a" ); mySSC.Add( "Two", "ab" ); mySSC.Add( "Three", "abc" ); mySSC.Add( "Four", "abcd" ); mySSC.Add( "Five", "abcde" ); // Display the contents of the collection using foreach. This is the preferred method. Console.WriteLine( "Contents of the collection (using foreach):" ); PrintKeysAndValues1( mySSC ); // Display the contents of the collection using the enumerator. Console.WriteLine( "Contents of the collection (using enumerator):" ); PrintKeysAndValues2( mySSC ); // Display the contents of the collection using the Keys property and the Item property. Console.WriteLine( "Initial contents of the collection (using Keys and Item):" ); PrintKeysAndValues3( mySSC ); // Tries to add a value that is too long. try { mySSC.Add( "Ten", "abcdefghij" ); } catch ( ArgumentException e ) { Console.WriteLine( e.ToString() ); } // Tries to add a key that is too long. try { mySSC.Add( "Eleven", "ijk" ); } catch ( ArgumentException e ) { Console.WriteLine( e.ToString() ); } Console.WriteLine(); // Searches the collection with Contains. Console.WriteLine( "Contains \"Three\": {0}", mySSC.Contains( "Three" ) ); Console.WriteLine( "Contains \"Twelve\": {0}", mySSC.Contains( "Twelve" ) ); Console.WriteLine(); // Removes an element from the collection. mySSC.Remove( "Two" ); // Displays the contents of the collection. Console.WriteLine( "After removing \"Two\":" ); PrintKeysAndValues1( mySSC ); } // Uses the foreach statement which hides the complexity of the enumerator. // NOTE: The foreach statement is the preferred way of enumerating the contents of a collection. public static void PrintKeysAndValues1( ShortStringDictionary myCol ) { foreach ( DictionaryEntry myDE in myCol ) Console.WriteLine( " {0,-5} : {1}", myDE.Key, myDE.Value ); Console.WriteLine(); } // Uses the enumerator. // NOTE: The foreach statement is the preferred way of enumerating the contents of a collection. public static void PrintKeysAndValues2( ShortStringDictionary myCol ) { DictionaryEntry myDE; System.Collections.IEnumerator myEnumerator = myCol.GetEnumerator(); while ( myEnumerator.MoveNext() ) if ( myEnumerator.Current != null ) { myDE = (DictionaryEntry) myEnumerator.Current; Console.WriteLine( " {0,-5} : {1}", myDE.Key, myDE.Value ); } Console.WriteLine(); } // Uses the Keys property and the Item property. public static void PrintKeysAndValues3( ShortStringDictionary myCol ) { ICollection myKeys = myCol.Keys; foreach ( String k in myKeys ) Console.WriteLine( " {0,-5} : {1}", k, myCol[k] ); Console.WriteLine(); } } /* This code produces the following output. Contents of the collection (using foreach): Three : abc Five : abcde Two : ab One : a Four : abcd Contents of the collection (using enumerator): Three : abc Five : abcde Two : ab One : a Four : abcd Initial contents of the collection (using Keys and Item): Three : abc Five : abcde Two : ab One : a Four : abcd System.ArgumentException: value must be no more than 5 characters in length. Parameter name: value at ShortStringDictionary.OnValidate(Object key, Object value) at System.Collections.DictionaryBase.System.Collections.IDictionary.Add(Object key, Object value) at SamplesDictionaryBase.Main() System.ArgumentException: key must be no more than 5 characters in length. Parameter name: key at ShortStringDictionary.OnValidate(Object key, Object value) at System.Collections.DictionaryBase.System.Collections.IDictionary.Add(Object key, Object value) at SamplesDictionaryBase.Main() Contains "Three": True Contains "Twelve": False After removing "Two": Three : abc Five : abcde One : a Four : abcd */
using namespace System; using namespace System::Collections; public ref class ShortStringDictionary: public DictionaryBase { public: property String^ Item [String^] { String^ get( String^ key ) { return (dynamic_cast<String^>(Dictionary[ key ])); } void set( String^ value, String^ key ) { Dictionary[ key ] = value; } } property ICollection^ Keys { ICollection^ get() { return (Dictionary->Keys); } } property ICollection^ Values { ICollection^ get() { return (Dictionary->Values); } } void Add( String^ key, String^ value ) { Dictionary->Add( key, value ); } bool Contains( String^ key ) { return (Dictionary->Contains( key )); } void Remove( String^ key ) { Dictionary->Remove( key ); } protected: virtual void OnInsert( Object^ key, Object^ value ) override { if ( key->GetType() != Type::GetType( "System.String" ) ) throw gcnew ArgumentException( "key must be of type String.","key" ); else { String^ strKey = dynamic_cast<String^>(key); if ( strKey->Length > 5 ) throw gcnew ArgumentException( "key must be no more than 5 characters in length.","key" ); } if ( value->GetType() != Type::GetType( "System.String" ) ) throw gcnew ArgumentException( "value must be of type String.","value" ); else { String^ strValue = dynamic_cast<String^>(value); if ( strValue->Length > 5 ) throw gcnew ArgumentException( "value must be no more than 5 characters in length.","value" ); } } virtual void OnRemove( Object^ key, Object^ /*value*/ ) override { if ( key->GetType() != Type::GetType( "System.String" ) ) throw gcnew ArgumentException( "key must be of type String.","key" ); else { String^ strKey = dynamic_cast<String^>(key); if ( strKey->Length > 5 ) throw gcnew ArgumentException( "key must be no more than 5 characters in length.","key" ); } } virtual void OnSet( Object^ key, Object^ /*oldValue*/, Object^ newValue ) override { if ( key->GetType() != Type::GetType( "System.String" ) ) throw gcnew ArgumentException( "key must be of type String.","key" ); else { String^ strKey = dynamic_cast<String^>(key); if ( strKey->Length > 5 ) throw gcnew ArgumentException( "key must be no more than 5 characters in length.","key" ); } if ( newValue->GetType() != Type::GetType( "System.String" ) ) throw gcnew ArgumentException( "newValue must be of type String.","newValue" ); else { String^ strValue = dynamic_cast<String^>(newValue); if ( strValue->Length > 5 ) throw gcnew ArgumentException( "newValue must be no more than 5 characters in length.","newValue" ); } } virtual void OnValidate( Object^ key, Object^ value ) override { if ( key->GetType() != Type::GetType( "System.String" ) ) throw gcnew ArgumentException( "key must be of type String.","key" ); else { String^ strKey = dynamic_cast<String^>(key); if ( strKey->Length > 5 ) throw gcnew ArgumentException( "key must be no more than 5 characters in length.","key" ); } if ( value->GetType() != Type::GetType( "System.String" ) ) throw gcnew ArgumentException( "value must be of type String.","value" ); else { String^ strValue = dynamic_cast<String^>(value); if ( strValue->Length > 5 ) throw gcnew ArgumentException( "value must be no more than 5 characters in length.","value" ); } } }; void PrintKeysAndValues2( ShortStringDictionary^ myCol ); void PrintKeysAndValues3( ShortStringDictionary^ myCol ); int main() { // Creates and initializes a new DictionaryBase. ShortStringDictionary^ mySSC = gcnew ShortStringDictionary; // Adds elements to the collection. mySSC->Add( "One", "a" ); mySSC->Add( "Two", "ab" ); mySSC->Add( "Three", "abc" ); mySSC->Add( "Four", "abcd" ); mySSC->Add( "Five", "abcde" ); // Display the contents of the collection using the enumerator. Console::WriteLine( "Contents of the collection (using enumerator):" ); PrintKeysAndValues2( mySSC ); // Display the contents of the collection using the Keys property and the Item property. Console::WriteLine( "Initial contents of the collection (using Keys and Item):" ); PrintKeysAndValues3( mySSC ); // Tries to add a value that is too long. try { mySSC->Add( "Ten", "abcdefghij" ); } catch ( ArgumentException^ e ) { Console::WriteLine( e ); } // Tries to add a key that is too long. try { mySSC->Add( "Eleven", "ijk" ); } catch ( ArgumentException^ e ) { Console::WriteLine( e ); } Console::WriteLine(); // Searches the collection with Contains. Console::WriteLine( "Contains \"Three\": {0}", mySSC->Contains( "Three" ) ); Console::WriteLine( "Contains \"Twelve\": {0}", mySSC->Contains( "Twelve" ) ); Console::WriteLine(); // Removes an element from the collection. mySSC->Remove( "Two" ); // Displays the contents of the collection. Console::WriteLine( "After removing \"Two\":" ); PrintKeysAndValues2( mySSC ); } // Uses the enumerator. void PrintKeysAndValues2( ShortStringDictionary^ myCol ) { DictionaryEntry myDE; System::Collections::IEnumerator^ myEnumerator = myCol->GetEnumerator(); while ( myEnumerator->MoveNext() ) if ( myEnumerator->Current != nullptr ) { myDE = *dynamic_cast<DictionaryEntry^>(myEnumerator->Current); Console::WriteLine( " {0,-5} : {1}", myDE.Key, myDE.Value ); } Console::WriteLine(); } // Uses the Keys property and the Item property. void PrintKeysAndValues3( ShortStringDictionary^ myCol ) { ICollection^ myKeys = myCol->Keys; IEnumerator^ myEnum1 = myKeys->GetEnumerator(); while ( myEnum1->MoveNext() ) { String^ k = safe_cast<String^>(myEnum1->Current); Console::WriteLine( " {0,-5} : {1}", k, myCol->Item[ k ] ); } Console::WriteLine(); } /* This code produces the following output. Contents of the collection (using enumerator): Three : abc Five : abcde Two : ab One : a Four : abcd Initial contents of the collection (using Keys and Item): Three : abc Five : abcde Two : ab One : a Four : abcd System.ArgumentException: value must be no more than 5 characters in length. Parameter name: value at ShortStringDictionary.OnValidate(Object key, Object value) at System.Collections.DictionaryBase.System.Collections.IDictionary.Add(Object key, Object value) at SamplesDictionaryBase.Main() System.ArgumentException: key must be no more than 5 characters in length. Parameter name: key at ShortStringDictionary.OnValidate(Object key, Object value) at System.Collections.DictionaryBase.System.Collections.IDictionary.Add(Object key, Object value) at SamplesDictionaryBase.Main() Contains "Three": True Contains "Twelve": False After removing "Two": Three : abc Five : abcde One : a Four : abcd */
import System.*; import System.Collections.*; public class ShortStringDictionary extends DictionaryBase { /** @property */ public String get_Value(String key) { return((String)(get_Dictionary().get_Item(key))); } //get_Value /** @property */ public void set_Value(String key,String value) { get_Dictionary().set_Item(key, value); } //set_Value /** @property */ public ICollection get_Keys() { return get_Dictionary().get_Keys(); } //get_Keys /** @property */ public ICollection get_Values() { return get_Dictionary().get_Values(); } //get_Values public void Add(String key, String value) { get_Dictionary().Add(key, value); } //Add public boolean Contains(String key) { return get_Dictionary().Contains(key); } //Contains public void Remove(String key) { get_Dictionary().Remove(key); } //Remove protected void OnInsert(Object key, Object value) { if (!key.GetType().Equals(Type.GetType("System.String"))) { throw new ArgumentException("key must be of type String.", "key"); } else { String strKey = ((String)(key)); if (strKey.length() > 5) { throw new ArgumentException("key must be no more than " + "5 characters in length.", "key"); } } if (!value.GetType().Equals(Type.GetType("System.String"))) { throw new ArgumentException("value must be of type String.", "value"); } else { String strValue = (String)value; if (strValue.length() > 5) { throw new ArgumentException("value must be no more than " + "5 characters in length.", "value"); } } } //OnInsert protected void OnRemove(Object key, Object value) { if (!key.GetType().Equals(Type.GetType("System.String"))) { throw new ArgumentException("key must be of type String.", "key"); } else { String strKey = ((String)(key)); if (strKey.length() > 5) { throw new ArgumentException("key must be no more than " + "5 characters in length.", "key"); } } } //OnRemove protected void OnSet(Object key, Object oldValue, Object newValue) { if (!key.GetType().Equals(Type.GetType("System.String"))) { throw new ArgumentException("key must be of type String.", "key"); } else { String strKey = (String)key; if (strKey.length() > 5) { throw new ArgumentException("key must be no more than " + "5 characters in length.", "key") ; } } if (!newValue.GetType().Equals(Type.GetType("System.String"))) { throw new ArgumentException("newValue must be of type String.", "newValue") ; } else { String strValue = ((String)(newValue)); if (strValue.length() > 5) { throw new ArgumentException("newValue must be no more than " + "5 characters in length.", "newValue") ; } } } //OnSet protected void OnValidate(Object key, Object value) { if (!key.GetType().Equals(Type.GetType("System.String"))) { throw new ArgumentException("key must be of type String.", "key"); } else { String strKey = ((String)(key)); if (strKey.length() > 5) { throw new ArgumentException("key must be no more than " + "5 characters in length.", "key") ; } } if (!value.GetType().Equals(Type.GetType("System.String"))) { throw new ArgumentException("value must be of type String.", "value"); } else { String strValue = ((String)(value)); if (strValue.length() > 5) { throw new ArgumentException("value must be no more than " + "5 characters in length.", "value") ; } } } //OnValidate } //ShortStringDictionary public class SamplesDictionaryBase { public static void main(String[] args) { // Creates and initializes a new DictionaryBase. ShortStringDictionary mySSC = new ShortStringDictionary(); // Adds elements to the collection. mySSC.Add("One", "a"); mySSC.Add("Two", "ab"); mySSC.Add("Three", "abc"); mySSC.Add("Four", "abcd"); mySSC.Add("Five", "abcde"); // Display the contents of the collection using while. This is the // preferred method. Console.WriteLine("Contents of the collection (using for):"); PrintKeysAndValues1(mySSC); // Display the contents of the collection using the enumerator. Console.WriteLine("Contents of the collection (using enumerator):"); PrintKeysAndValues2(mySSC); // Display the contents of the collection using the Keys property and // the Item property. Console.WriteLine("Initial contents of the collection (using Keys" + " and Item):"); PrintKeysAndValues3(mySSC); // Tries to add a value that is too long. try { mySSC.Add("Ten", "abcdefghij"); } catch(ArgumentException e) { Console.WriteLine(e.ToString()); } // Tries to add a key that is too long. try { mySSC.Add("Eleven", "ijk"); } catch(ArgumentException e) { Console.WriteLine(e.ToString()); } Console.WriteLine(); // Searches the collection with Contains. boolean b = mySSC.Contains("Three"); Console.Write("Contains \"Three\": "); Console.WriteLine(b); b = mySSC.Contains("Twelve"); Console.Write("Contains \"Twelve\": "); Console.WriteLine(b); Console.WriteLine(); // Removes an element from the collection. mySSC.Remove("Two"); // Displays the contents of the collection. Console.WriteLine("After removing \"Two\":"); PrintKeysAndValues1(mySSC); }//main // Uses the for statement which hides the complexity of the enumerator. // NOTE: The for statement is the preferred way of enumerating the // contents of a collection. public static void PrintKeysAndValues1(ShortStringDictionary myCol) { String strValue; String strKeys[] = new String[myCol.get_Count()]; myCol.get_Keys().CopyTo(strKeys,0); for (int iCtr = 0; iCtr < myCol.get_Count(); iCtr++){ strValue = myCol.get_Value(strKeys[iCtr]); Console.WriteLine(" {0,-5} : {1}", strKeys[iCtr], strValue); } Console.WriteLine(); } //PrintKeysAndValues1 // Uses the enumerator. // NOTE: The for statement is the preferred way of enumerating the // contents of a collection. public static void PrintKeysAndValues2(ShortStringDictionary myCol) { DictionaryEntry myDE; System.Collections.IEnumerator myEnumerator = myCol.GetEnumerator(); while(myEnumerator.MoveNext()) { if ( myEnumerator.get_Current() != null ) { myDE =((DictionaryEntry)(myEnumerator.get_Current())); Console.WriteLine(" {0,-5} : {1}", myDE.get_Key(), myDE.get_Value()); } } Console.WriteLine(); } //PrintKeysAndValues2 // Uses the Keys property and the Value property. public static void PrintKeysAndValues3(ShortStringDictionary myCol) { ICollection myKeys = myCol.get_Keys(); IEnumerator myEnumerator = myKeys.GetEnumerator(); while (myEnumerator.MoveNext()) { String k = myEnumerator.get_Current().ToString(); Console.WriteLine(" {0,-5} : {1}", k, myCol.get_Item(k)); } Console.WriteLine(); } //PrintKeysAndValues3 } //SamplesDictionaryBase /* This code produces the following output. Contents of the collection (using while): Three : abc Five : abcde Two : ab One : a Four : abcd Contents of the collection (using enumerator): Three : abc Five : abcde Two : ab One : a Four : abcd Initial contents of the collection (using Keys and Item): Three : abc Five : abcde Two : ab One : a Four : abcd System.ArgumentException: value must be no more than 5 characters in length. Parameter name: value at ShortStringDictionary.OnValidate(Object key, Object value) at System.Collections.DictionaryBase.System.Collections.IDictionary.Add( Object key, Object value) at SamplesDictionaryBase.Main() System.ArgumentException: key must be no more than 5 characters in length. Parameter name: key at ShortStringDictionary.OnValidate(Object key, Object value) at System.Collections.DictionaryBase.System.Collections.IDictionary.Add( Object key, Object value) at SamplesDictionaryBase.Main() Contains "Three": True Contains "Twelve": False After removing "Two": Three : abc Five : abcde One : a Four : abcd */

Windows 98, Windows 2000 SP4, Windows Millennium Edition, Windows Server 2003, Windows XP Media Center Edition, Windows XP Professional x64 Edition, Windows XP SP2, Windows XP Starter Edition
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- DictionaryBase.GetEnumerator メソッドのページへのリンク