读取和写入文件以进行身份​​验证

Question

I have been trying to make a simple authentication system in c#. I am trying to make it read a text file and if it has the correct answer/username, continue. If it doesn't it has a textbox.Show on it. My current code for this is:

if(textBox1.Text == "wlkey1")
{
    Hide();
    string fileName1 ="authentication.txt";
    System.IO.File.WriteAllText(fileName1, textBox1.Text);
}
else{
    MessageBox.Show("Yikes. That's incorrect.", "Uh oh.");
}

Answer 1

You are Writing to file instead of reading it. you must use ReadAllText()

string fileName1 ="authentication.txt";
string curPass = "someDefaultPass";
if(System.IO.File.Exists(fileName1)
    curPass = System.IO.File.ReadAllText(fileName1);
if(textBox1.Text == curPass)
{
    Hide();
}
else{
    MessageBox.Show("Yikes. That's incorrect.", "Uh oh.");
}

By the way, as you may already know, saving passwords on a file is not secure.

for writing well you have already done it:

string fileName1 ="authentication.txt";
System.IO.File.WriteAllText(fileName1, textBox1.Text);