SecureString 建構函式

定義

命名空間:
System.Security
組件:
mscorlib.dll
組件:
netstandard.dll

初始化 SecureString 類別的新執行個體。

多載

名稱 Description
SecureString()

初始化 SecureString 類別的新執行個體。
SecureString(Char*, Int32)

從一個物件子陣列Char初始化該SecureString類別的新實例。

此建構器不符合 CLS 標準。 符合 CLS 標準的替代方案為 SecureString()。

SecureString()

初始化 SecureString 類別的新執行個體。

public:
 SecureString();
public SecureString();
Public Sub New ()

例外狀況

CryptographicException

在保護或解除保護該實例值時發生錯誤。

NotSupportedException

此操作不支援此平台。

範例

以下範例使用預設（或無參數）建構子來實例化一個新 SecureString 物件。 接著它會呼叫該 AppendChar 方法，加入一個字元陣列。

using System;
using System.Security;

public class Example
{
   public static void Main()
   {
      // Define the string value to assign to a new secure string.
      char[] chars = { 't', 'e', 's', 't' };
      // Instantiate the secure string.
      SecureString testString = new SecureString();
      // Assign the character array to the secure string.
      foreach (char ch in chars)
         testString.AppendChar(ch);      
      // Display secure string length.
      Console.WriteLine("The length of the string is {0} characters.", 
                        testString.Length);
      testString.Dispose();
   }
}
// The example displays the following output:
//      The length of the string is 4 characters.

Imports System.Security

Module Example
   Public Sub Main()
      ' Define the string value to assign to a new secure string.
      Dim chars() As Char = { "t"c, "e"c, "s"c, "t"c }
      ' Instantiate the secure string.
      Dim testString As SecureString = New SecureString()
      ' Assign the character array to the secure string.
      For Each ch As char In chars
         testString.AppendChar(ch)
      Next         
      ' Display secure string length.
      Console.WriteLine("The length of the string is {0} characters.", _ 
                        testString.Length)
      testString.Dispose()
   End Sub
End Module
' The example displays the following output:
'      The length of the string is 4 characters.

以下範例由物件String的值建立一個SecureString物件。

using System;
using System.Security;

public class Example
{
   public static void Main()
   {
      // Define the string value to be assigned to the secure string.
      string initString = "TestString";
      // Instantiate the secure string.
      SecureString testString = new SecureString();
      // Use the AppendChar method to add each char value to the secure string.
      foreach (char ch in initString)
         testString.AppendChar(ch);
         
      // Display secure string length.
      Console.WriteLine("The length of the string is {0} characters.", 
                        testString.Length);
      testString.Dispose();
   }
}
// The example displays the following output:
//      The length of the string is 10 characters.

Imports System.Security

Module Example
   Public Sub Main()
      ' Define the string value to be assigned to the secure string.
      Dim initString As String = "TestString"
      ' Instantiate the secure string.
      Dim testString As SecureString = New SecureString()
      ' Use the AppendChar method to add each char value to the secure string.
      For Each ch As Char In initString
         testString.AppendChar(ch)
      Next   
      ' Display secure string length.
      Console.WriteLine("The length of the string is {0} characters.", _ 
                        testString.Length)
      testString.Dispose()
   End Sub
End Module
' The example displays the following output:
'      The length of the string is 10 characters.

適用於

SecureString(Char*, Int32)

重要

此 API 不符合 CLS 規範。

從一個物件子陣列Char初始化該SecureString類別的新實例。

此建構器不符合 CLS 標準。 符合 CLS 標準的替代方案為 SecureString()。

public:
 SecureString(char* value, int length);
[System.CLSCompliant(false)]
public SecureString(char* value, int length);
[System.CLSCompliant(false)]
[System.Security.SecurityCritical]
public SecureString(char* value, int length);
[<System.CLSCompliant(false)>]
new System.Security.SecureString : nativeptr<char> * int -> System.Security.SecureString
[<System.CLSCompliant(false)>]
[<System.Security.SecurityCritical>]
new System.Security.SecureString : nativeptr<char> * int -> System.Security.SecureString

參數

value
Char*

Char 物件陣列的指標。

length
Int32

新實例中要包含的 value 元素數量。

屬性
CLSCompliantAttribute SecurityCriticalAttribute

例外狀況

ArgumentNullException

value 是 null。

ArgumentOutOfRangeException

length 小於零或大於65,536。

CryptographicException

在保護或解除保護這個安全字串值時發生錯誤。

NotSupportedException

此操作不支援此平台。

範例

以下範例透過將建構子傳遞指向字元陣列的指標來實例化一個新 SecureString 物件。

using System;
using System.Security;

public class Example
{
   unsafe public static void Main()
   {
      SecureString testString;
      // Define the string value to assign to a new secure string.
      char[] chars = { 't', 'e', 's', 't' };

      // Instantiate a new secure string.
      fixed(char* pChars = chars)
      {
         testString = new SecureString(pChars, chars.Length);
      }
      // Display secure string length.
      Console.WriteLine("The length of the string is {0} characters.", 
                        testString.Length);
      testString.Dispose();
   }
}
// The example displays the following output:
//      The length of the string is 4 characters.

備註

此建構器會將新 SecureString 物件初始化為 中 value 指定的 length字元數;接著該實例的值會被加密。

在 C# 中，這個建構子僅在不安全程式碼的上下文中被定義。

適用於