从文件返回的字符串与原始文件c ++不匹配

Question

我要做的是创建一个加密工具。它将文件转换为字符串。然后该字符串将被加密。但是，在将文件转换为字符串并再次保存该文件时（出于测试目的），返回的文件与原始文件不同，即使在更改扩展名后也无法打开。请帮忙：

String^ fileNME = textBox1->Text;   //File is selected via fileopendialog and then copied to TextBox1

    //Convert from System::String to std::string. result is actually a string that holds     the filename.
    string result("a");

    result = marshal_as<std::string>( fileNME );



    string fileToEncryptasString;

    fileToEncryptasString = fileToString(result);

myfile.open ("filecopy.txt");
myfile << fileToEncryptasString;
myfile.close();

//File to String function is this:

string fileToString(const string& filename)
{
ifstream file(filename, ios::binary);
if (!file) return "";
string str(istreambuf_iterator<char>(file),
           (istreambuf_iterator<char>()));
return str;
}