SecureString.Clear Yöntem
Tanım
Önemli
Bazı bilgiler ürünün ön sürümüyle ilgilidir ve sürüm öncesinde önemli değişiklikler yapılmış olabilir. Burada verilen bilgilerle ilgili olarak Microsoft açık veya zımni hiçbir garanti vermez.
Geçerli güvenli dizenin değerini siler.
public:
void Clear();
public void Clear ();
member this.Clear : unit -> unit
Public Sub Clear ()
Özel durumlar
Bu güvenli dize zaten atılmış.
Bu güvenli dize salt okunurdur.
Örnekler
Aşağıdaki örnekte , , InsertAt, SetAtRemoveAtve Clear yöntemlerinin AppendCharbir SecureString nesnenin değerini nasıl etkilediği gösterilmektedir.
using namespace System;
using namespace System::Security;
void main()
{
String^ msg = L" The current length of the SecureString object: {0}\n";
SecureString ^ ss = gcnew SecureString;
Console::WriteLine(L"1) Instantiate the SecureString object:");
Console::WriteLine(msg, ss->Length );
Console::WriteLine(L"2) Append 'a' to the value:");
ss->AppendChar('a');
Console::WriteLine(msg, ss->Length );
Console::WriteLine(L"3) Append 'X' to the value:");
ss->AppendChar('X');
Console::WriteLine(msg, ss->Length);
Console::WriteLine(L"4) Append 'c' to the value:");
ss->AppendChar('c');
Console::WriteLine(msg, ss->Length);
Console::WriteLine(L"5) Insert 'd' at the end of the value:");
ss->InsertAt(ss->Length, 'd');
Console::WriteLine(msg, ss->Length);
Console::WriteLine(L"6) Remove the last character ('d') from the value:");
ss->RemoveAt(3);
Console::WriteLine(msg, ss->Length);
Console::WriteLine(L"7) Set the second character ('X') of the value to 'b':" );
ss->SetAt(1, 'b');
Console::WriteLine(msg, ss->Length );
Console::WriteLine(L"8) Delete the value of the SecureString object:");
ss->Clear();
Console::WriteLine(msg, ss->Length);
delete ss;
}
/*
This code example produces the following results:
This example demonstrates the effect of the AppendChar, InsertAt,
RemoveAt, SetAt, and Clear methods on the value of a SecureString
object. This example simulates the value of the object because the
actual value is encrypted.
1) The initial value of the SecureString object:
SecureString = ""
Length = 0
2) AppendChar: Append 'a' to the value:
SecureString = "a"
Length = 1
3) AppendChar: Append 'X' to the value:
SecureString = "aX"
Length = 2
4) AppendChar: Append 'c' to the value:
SecureString = "aXc"
Length = 3
5) InsertAt: Insert 'd' at the end of the value (equivalent
to AppendChar):
SecureString = "aXcd"
Length = 4
6) RemoveAt: Remove the last character ('d') from the value:
SecureString = "aXc"
Length = 3
7) SetAt: Set the second character ('X') of the value to 'b':
SecureString = "abc"
Length = 3
8) Clear: Delete the value of the SecureString object:
SecureString = ""
Length = 0
*/
using System;
using System.Security;
class Example
{
public static void Main()
{
string msg = "The curent length of the SecureString object: {0}\n";
Console.WriteLine("1) Instantiate the SecureString object.");
SecureString ss = new SecureString();
Console.WriteLine(msg, ss.Length);
Console.WriteLine("2) Append 'a' to the value.");
ss.AppendChar('a');
Console.WriteLine(msg, ss.Length);
Console.WriteLine("3) Append 'X' to the value.");
ss.AppendChar('X');
Console.WriteLine(msg, ss.Length);
Console.WriteLine("4) Append 'c' to the value.");
ss.AppendChar('c');
Console.WriteLine(msg, ss.Length);
Console.WriteLine("5) Insert 'd' at the end of the value.");
ss.InsertAt(ss.Length, 'd');
Console.WriteLine(msg, ss.Length);
Console.WriteLine("6) Remove the last character ('d') from the value.");
ss.RemoveAt(3);
Console.WriteLine(msg, ss.Length);
Console.WriteLine("7) Set the second character of the value to 'b'.");
ss.SetAt(1, 'b');
Console.WriteLine(msg, ss.Length);
Console.WriteLine("8) Delete the value of the SecureString object:");
ss.Clear();
Console.WriteLine(msg, ss.Length);
ss.Dispose();
}
}
// The example displays the following output:
// 1) Instantiate the SecureString object.
// The curent length of the SecureString object: 0
//
// 2) Append 'a' to the value.
// The curent length of the SecureString object: 1
//
// 3) Append 'X' to the value.
// The curent length of the SecureString object: 2
//
// 4) Append 'c' to the value.
// The curent length of the SecureString object: 3
//
// 5) Insert 'd' at the end of the value.
// The curent length of the SecureString object: 4
//
// 6) Remove the last character ('d') from the value.
// The curent length of the SecureString object: 3
//
// 7) Set the second character of the value to 'b'.
// The curent length of the SecureString object: 3
//
// 8) Delete the value of the SecureString object:
// The curent length of the SecureString object: 0
Imports System.Security
Module Example
Public Sub Main()
Dim msg As String = "The curent length of the SecureString object: {0}" + vbCrLf
Console.WriteLine("1) Instantiate the SecureString object.")
Dim ss As New SecureString()
Console.WriteLine(msg, ss.Length)
Console.WriteLine("2) Append 'a' to the value.")
ss.AppendChar("a"c)
Console.WriteLine(msg, ss.Length)
Console.WriteLine("3) Append 'X' to the value.")
ss.AppendChar("X"c)
Console.WriteLine(msg, ss.Length)
Console.WriteLine("4) Append 'c' to the value.")
ss.AppendChar("c"c)
Console.WriteLine(msg, ss.Length)
Console.WriteLine("5) Insert 'd' at the end of the value.")
ss.InsertAt(ss.Length, "d"c)
Console.WriteLine(msg, ss.Length)
Console.WriteLine("6) Remove the last character ('d') from the value.")
ss.RemoveAt(3)
Console.WriteLine(msg, ss.Length)
Console.WriteLine("7) Set the second character of the value to 'b'.")
ss.SetAt(1, "b"c)
Console.WriteLine(msg, ss.Length)
Console.WriteLine("8) Delete the value of the SecureString object:")
ss.Clear()
Console.WriteLine(msg, ss.Length)
ss.Dispose()
End Sub
End Module
' The example displays the following output:
' 1) Instantiate the SecureString object.
' The curent length of the SecureString object: 0
'
' 2) Append 'a' to the value.
' The curent length of the SecureString object: 1
'
' 3) Append 'X' to the value.
' The curent length of the SecureString object: 2
'
' 4) Append 'c' to the value.
' The curent length of the SecureString object: 3
'
' 5) Insert 'd' at the end of the value.
' The curent length of the SecureString object: 4
'
' 6) Remove the last character ('d') from the value.
' The curent length of the SecureString object: 3
'
' 7) Set the second character of the value to 'b'.
' The curent length of the SecureString object: 3
'
' 8) Delete the value of the SecureString object:
' The curent length of the SecureString object: 0
Açıklamalar
Bu güvenli dizenin değerini içeren bilgisayar belleği sıfırlanır, ardından bu güvenli dizenin değerinin uzunluğu sıfır olarak ayarlanır.
Şunlara uygulanır
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