Marshal.SecureStringToCoTaskMemAnsi(SecureString) 方法

定義

命名空間:

System.Runtime.InteropServices

組件:

System.Runtime.InteropServices.dll

來源:

Marshal.cs

重要

此 API 不符合 CLS 規範。

將 Managed SecureString 物件的內容複製到從 Unmanaged COM 工作配置器配置的記憶體區塊。

public:
 static IntPtr SecureStringToCoTaskMemAnsi(System::Security::SecureString ^ s);

public static IntPtr SecureStringToCoTaskMemAnsi (System.Security.SecureString s);

static member SecureStringToCoTaskMemAnsi : System.Security.SecureString -> nativeint

Public Shared Function SecureStringToCoTaskMemAnsi (s As SecureString) As IntPtr

參數

s

SecureString

要複製的 Managed 物件。

傳回

IntPtr

nativeint

Unmanaged 記憶體中複製 s 參數的目的位址；如果提供 Null 物件，則為 0。

例外狀況

ArgumentNullException

s 參數為 null。

OutOfMemoryException

可用的記憶體不足。

範例

下列範例會 SecureStringToCoTaskMemAnsi 使用 方法，將 對象的內容 SecureString 封送處理和解密為 Unmanaged 記憶體區塊。 然後它會 ZeroFreeCoTaskMemAnsi 使用 方法來零出並處置 Unmanaged 區塊。

using System;
using System.Runtime.InteropServices;
using System.Security;

class MarshalExample
{
     static void Main()
     {
         IntPtr unmanagedRef = IntPtr.Zero;

          // Ask the user for a password.
          Console.Write("Please enter your password: ");

          SecureString passWord = GetPassword();

          Console.WriteLine("Copying and decrypting the string to unmanaged memory...");

          // Copy the Secure string to unmanaged memory (and decrypt it).
          unmanagedRef = Marshal.SecureStringToCoTaskMemAnsi(passWord);

          if (unmanagedRef != IntPtr.Zero)
          {
              Console.WriteLine("Zeroing out unmanaged memory...");

              Marshal.ZeroFreeCoTaskMemAnsi(unmanagedRef);
          }
          passWord.Dispose();

         Console.WriteLine("Done.");
     }

     public static SecureString GetPassword()
     {
         SecureString password = new SecureString();

         // get the first character of the password
         ConsoleKeyInfo nextKey = Console.ReadKey(true);

         while (nextKey.Key != ConsoleKey.Enter)
         {
             if (nextKey.Key == ConsoleKey.Backspace)
             {
                 if (password.Length > 0)
                 {
                     password.RemoveAt(password.Length - 1);

                     // erase the last * as well
                     Console.Write(nextKey.KeyChar);
                     Console.Write(" ");
                     Console.Write(nextKey.KeyChar);
                 }
             }
             else
             {
                 password.AppendChar(nextKey.KeyChar);
                 Console.Write("*");
             }

             nextKey = Console.ReadKey(true);
         }

         Console.WriteLine();

         // lock the password down
         password.MakeReadOnly();
         return password;
     }
}

Imports System.Runtime.InteropServices
Imports System.Security

Module Example
    Sub Main()
        Dim unmanagedRef As IntPtr

         ' Ask the user for a password.
         Console.Write("Please enter your password: ")
         Dim passWord As SecureString = GetPassword()

         Console.WriteLine("Copying and decrypting the string to unmanaged memory...")

         ' Copy the Secure string to unmanaged memory (and decrypt it).
         unmanagedRef = Marshal.SecureStringToCoTaskMemAnsi(passWord)

         If unmanagedRef <> IntPtr.Size Then
             Console.WriteLine("Zeroing out unmanaged memory...")
             Marshal.ZeroFreeCoTaskMemAnsi(unmanagedRef)
         End If
         passWord.Dispose()

        Console.WriteLine("Done.")
    End Sub



    Function GetPassword() As SecureString
        Dim password As New SecureString()

        ' get the first character of the password
        Dim nextKey As ConsoleKeyInfo = Console.ReadKey(True)

        While nextKey.Key <> ConsoleKey.Enter
            If nextKey.Key = ConsoleKey.BackSpace Then
                If password.Length > 0 Then
                    password.RemoveAt(password.Length - 1)

                    ' erase the last * as well
                    Console.Write(nextKey.KeyChar)
                    Console.Write(" ")
                    Console.Write(nextKey.KeyChar)
                End If
            Else
                password.AppendChar(nextKey.KeyChar)
                Console.Write("*")
            End If

            nextKey = Console.ReadKey(True)
        End While

        Console.WriteLine()

        ' lock the password down
        password.MakeReadOnly()
        Return password

    End Function
End Module

備註

方法 SecureStringToCoTaskMemAnsi 適用於自定義封送處理，或在混合 Managed 和 Unmanaged 程式代碼時使用。 因為這個方法會配置字串所需的 Unmanaged 記憶體，所以一律會呼叫 ZeroFreeCoTaskMemAnsi來釋放記憶體。 字串的字元會複製為 ANSI 字元。