login Form Windows Form Application

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in much simplified form it could be written along these lines:

//login form handles everything and 
//gets user's real name
MyLoginForm loginForm = new MyLoginForm();

//login succeeded 
if(loginForm.DialogResult == DialogResult.OK)
{
   MyOther frm = new MyOtherForm();
   //set forms properties, user's real name including
   //i.e. 
   //frm.PropertyToHandleUserRealName = 
   //loginForm.PropertyToHandleUserRealName 
   frm.Show();
} 

Hello

It depands to the Workflow of the application.

I prefer it for small applications:

1. Have a main form.

2. In Form_Load event:

LoginForm loginForm = new LoginForm();
this.AddOwnedForm(loginForm);

while (!loginForm.IsAuthenticated)
{              
    if (loginForm.ShowDialog() != System.Windows.Forms.DialogResult.Cancel)
    {
        this.Close();
        break;
    }
}

//Show username

3. And a little change in LoginForm:

you need at least 2 extra properties:

public bool IsAuthenticated { get; set; }
public string UserName { get; set; }

Before closing the LoginForm check the userName and password and if they are ok, then IsAuthenticated = true; and this.UserName = UserNameTextBox.Text;

In Click event of Ok or Login button, Set:

this.DialogResult = System.Windows.Forms.DialogResult.OK;

Specify the Cancel button

if(textbox1.text=="admin" && textbox2.text=="admin")
{
Form1 ff = new Form1();
ff.show();
}
else
{
Messagebox.show("Please Enter the correct Username or Password");
}