Login implementation in WinForm

In a 1-like C/S system, the login function is basically a prerequisite,
Three methods to implement C# Winform login function are summarized.
type 1: changes the application entry to the main window in the application Settings code (Program.cs)
It sounds a bit convoluted, that is, when the application is initialized, the first page to load is the main page after we log in.
1. Set Application.Run in Program.cs:

Application.Run(new FormMain());// Sets the window to load when the application runs  

2. Add the login button event private void button1_Click(object sender, EventArgs e) code

private void button1_Click(object sender, EventArgs e)// The login  
{ 
if (this.textBoxPassword.Text == "") 
{ 
MessageBox.Show(" Please enter your password! "); 
} 
else if (this.textBoxUsername.Text=="123" && this.textBoxPassword.Text == "123") 
{ 
this.DialogResult = DialogResult.OK; 
this.Close(); 
} 
else 
{ 
MessageBox.Show("Username or Password Error"); 
} 
}

3, add the main window formMain load time event code

private void main_Load(object sender, EventArgs e) 
{ 
Form formLogin = new login(); 
formLogin.ShowDialog(); 
if (formLogin.DialogResult == DialogResult.OK)// If the login box returns DialogResult.OK 
{ 
MessageBox.Show(" Normal login "); 
} 
else 
{ 
this.Close(); 
} 
}

Design logic:

First, the program load main window formMain, then formMain will new1 login login window and pop-up window, and then close itself. this.DialogResult = DialogResult.OK; And close the login box. After closing the main_Load event of formMain again determines whether DialogResult of the login box is OK, and if so, loads the main window.

type 2: controls whether or not Application.Run () is executed by login authentication.

The code is as follows:

Form formLogin = new login(); 
formLogin.ShowDialog(); 
if (formLogin.DialogResult == DialogResult.OK) 
{ 
Application.Run(new formMain()); 
} 
else 
{ 
return; 
}

The principle of this method is simpler to understand than that of the first one. When the application is initialized, the login window is first loaded and verified.

type 3: directly hides the login box (note: hide, this.Hide () instead of this.Close ()) after passing the login verification. It's easier to understand this way.