I have login form and main form , how I make button enable = false when the login is user?

Question

1.00/5 (1 vote)

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form1 is loginform, and form2 has button i want make this button is enabled false...

This is Code in login form:-

s = "select Role_id from Users where User_name = '" + txt_UserName.Text + "' and Password = '" + txt_Password.Text + "' and Role = 'User' ";
sdAdapter = new SqlDataAdapter(s, con);
dt = new DataTable();
sdAdapter.Fill(dt);
if (dt.Rows.Count == 1)
{
string s2 = " insert into LoginAndOutDate(user_name, Login_Date) ";
s2 = s2 + " values(@user_name, CURRENT_TIMESTAMP) ";

if (con.State == ConnectionState.Closed)
con.Open();

using (sCommand = new SqlCommand(s2, con))
{
sCommand.Parameters.AddWithValue("@user_name", txt_UserName.Text);
sCommand.ExecuteNonQuery();
}

if (con.State == ConnectionState.Open)
con.Close();

this.Hide();
FRM_Main frm = new FRM_Main(txt_UserName.Text);
frm.RefToFormLogin = this;
frm.Show();
txt_Password.Clear();

What I have tried:

How i make button is enabled = false from another form

Posted 19-Aug-16 23:56pm

MahmoudOmar

Updated 20-Aug-16 0:04am

v2

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Comments

Richard Deeming 20-Aug-16 8:09am

Your code is vulnerable to SQL Injection[^]. NEVER use string concatenation to build a SQL query. ALWAYS use a parameterized query.

Everything you wanted to know about SQL injection (but were afraid to ask) | Troy Hunt[^]
How can I explain SQL injection without technical jargon? | Information Security Stack Exchange[^]
Query Parameterization Cheat Sheet | OWASP[^]

Richard Deeming 20-Aug-16 8:09am

Also, never store passwords in plain text. Only store a salted hash of the password, using a unique salt per record.

Secure Password Authentication Explained Simply[^]
Salted Password Hashing - Doing it Right[^]

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OriginalGriff · Accepted Answer · 2016-08-20T00:04:00

Solution 1

Easiest way is to add a second parameter to your form constructor:

C#

public FRM_Main(string userName, bool enableMyButton)
   {
   InitializeComponent();
   ...
   myButton.Enabled = enableMyButton;
   }

And then pass the appropriate value when you construct the form instance.

Posted 20-Aug-16 0:04am

OriginalGriff

Comments

MahmoudOmar 20-Aug-16 6:13am

How i pass this parameter to form login, because i do that but it's not working

OriginalGriff 20-Aug-16 6:22am

Show exactly the code you used in the constructor and when you create the instance.

MahmoudOmar 20-Aug-16 6:24am

thanks i found my error and it's working know :)

OriginalGriff 20-Aug-16 6:36am

Excellent!