如何在用户保存时使用户无法读取文件+ VB.net/C#

Question

如果用户只有在保存到磁盘时才能让文件无法读取，比如在C盘上？

Answer 1

如果数据源自应用程序，并且仅适用于同一台Windows计算机上的当前用户，

// using System.Security.Cryptography;

var path = Environment.GetFolderPath(Environment.SpecialFolder.ApplicationData) + 
    @"/user data that only a program run by this user can read.dat";
Console.WriteLine(path);
var entropy = Encoding.UTF8.GetBytes("See http://security.stackexchange.com/a/58121");


var data = Encoding.UTF8.GetBytes(
    @"Data to be stored in a way that only programs that run under 
    this account can decrypt but nobody's eyes can understand. But 
    if an admin forces a password change, it's irretrievable 
    (see http://stackoverflow.com/a/4755929/2226988).");
File.WriteAllBytes(path, ProtectedData.Protect(
    data, 
    entropy, 
    DataProtectionScope.CurrentUser));


var readBack = ProtectedData.Unprotect(
    File.ReadAllBytes(path), 
    entropy, 
    DataProtectionScope.CurrentUser);
Console.WriteLine(Encoding.UTF8.GetString(readBack));