sofeng
need help to subject
Object Property Settings Label1 Name lbllogin Text Login Label2 Name lblname Text Hi,Guest! Label3 Text Username Label4 Text Password Textbox1 Name txtuname Textbox2 Name txtpass PasswordChar * Button1 Name btnok Text OK Button2 Name btncancel Text CancelAfter setting the Object properties, arrange all the objects like as shown below. This time, let’s we are now ready to add functionality to our application. To do this, double click the form and add the following code: This code will simply disable the group box that holding the label Username and Password same with the two textbox and two Buttons.
GroupBox1.Enabled = False
If lbllogin.Text = "Logout" Then lbllogin.Text = "Login" lblname.Text = "Hi, Guest!" ElseIf lbllogin.Text = "Login" Then GroupBox1.Enabled = True End If
'Represents an SQL statement or stored procedure to execute against a data source. Dim cmd As New MySqlCommand Dim da As New MySqlDataAdapter 'declare conn as connection and it will now a new connection because 'it is equal to Getconnection Function Dim con As MySqlConnection = jokenconn() Public Function jokenconn() As MySqlConnection Return New MySqlConnection("server=localhost;user id=root;password=;database=studentdb") End Function
Dim sql As String Dim publictable As New DataTable Try 'check if the textbox is equal to nothing then it will display the message below!. If txtuname.Text = "" And txtpass.Text = "" Then Else sql = "select * from tbluseraccounts where username ='" & txtuname.Text & "' and userpassword = '" & txtpass.Text & "'" 'bind the connection and query With cmd .Connection = con .CommandText = sql End With da.SelectCommand = cmd da.Fill(publictable) 'check if theres a result by getting the count number of rows If publictable.Rows.Count > 0 Then 'it gets the data from specific column and assign to the variable Dim user_type, name As String user_type = publictable.Rows(0).Item(4) name = publictable.Rows(0).Item(2) 'check if the type of user is admin If user_type = "Admin" Then 'welcomes the user as Admiistrator 'set the lbllogin text to Logout lbllogin.Text = "Logout" 'disabled the groupbox GroupBox1.Enabled = False 'reset all the two textbox txtuname.Text = "" txtpass.Text = "" 'set the lblname to the specific user lblname.Text = "Hi, " & name ElseIf user_type = "Encoder" Then lbllogin.Text = "Logout" GroupBox1.Enabled = False txtuname.Text = "" txtpass.Text = "" lblname.Text = "Hi, " & name Else lbllogin.Text = "Logout" GroupBox1.Enabled = False txtuname.Text = "" txtpass.Text = "" lblname.Text = "Hi, " & name End If Else txtuname.Text = "" txtpass.Text = "" End If da.Dispose() End If Catch ex As Exception End Try con.Clone()
-- -- Dumping data for table `tbluseraccounts` -- (1, 'admin', 'Joken Villanueva', 'admin123', 'Admin'), (2, 'jason', 'Jason Batuto', 'jason123', 'Encoder');
Imports MySql.Data.MySqlClient Public Class Form1 'Represents an SQL statement or stored procedure to execute against a data source. Dim cmd As New MySqlCommand Dim da As New MySqlDataAdapter 'declare conn as connection and it will now a new connection because 'it is equal to Getconnection Function Dim con As MySqlConnection = jokenconn() Public Function jokenconn() As MySqlConnection Return New MySqlConnection("server=localhost;user id=root;password=;database=studentdb") End Function Private Sub btnlogin_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles btnlogin.Click Dim sql As String Dim publictable As New DataTable Try 'check if the textbox is equal to nothing then it will display the message below!. If txtuname.Text = "" And txtpass.Text = "" Then Else sql = "select * from tbluseraccounts where username ='" & txtuname.Text & "' and userpassword = '" & txtpass.Text & "'" 'bind the connection and query With cmd .Connection = con .CommandText = sql End With da.SelectCommand = cmd da.Fill(publictable) 'check if theres a result by getting the count number of rows If publictable.Rows.Count > 0 Then 'it gets the data from specific column and assign to the variable Dim user_type, name As String user_type = publictable.Rows(0).Item(4) name = publictable.Rows(0).Item(2) 'check if the type of user is admin If user_type = "Admin" Then 'welcomes the user as Admiistrator 'set the lbllogin text to Logout lbllogin.Text = "Logout" 'disabled the groupbox GroupBox1.Enabled = False 'reset all the two textbox txtuname.Text = "" txtpass.Text = "" 'set the lblname to the specific user lblname.Text = "Hi, " & name ElseIf user_type = "Encoder" Then lbllogin.Text = "Logout" GroupBox1.Enabled = False txtuname.Text = "" txtpass.Text = "" lblname.Text = "Hi, " & name Else lbllogin.Text = "Logout" GroupBox1.Enabled = False txtuname.Text = "" txtpass.Text = "" lblname.Text = "Hi, " & name End If Else txtuname.Text = "" txtpass.Text = "" End If da.Dispose() End If Catch ex As Exception End Try con.Clone() End Sub Private Sub lbllogin_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles lbllogin.Click If lbllogin.Text = "Logout" Then lbllogin.Text = "Login" lblname.Text = "Hi, Guest!" ElseIf lbllogin.Text = "Login" Then GroupBox1.Enabled = True End If End Sub Private Sub Form1_Load(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles MyBase.Load GroupBox1.Enabled = False End Sub End Class
I'm thinking line 5
If txtuname.Text = "" And txtpass.Text = "" Then
should Be
If txtuname.Text = "" Or txtpass.Text = "" Then
That way it would match your comment and properly test for null strings.