I don't normally post on forums because I try to find information for myself, and ask as an absolute last resort. I've tried scouring the net for answers, but I'm only receiving about half of the answer I'm looking for.
I'm currently building an application that deals with state law. There's one combo box and one text box. One for the offense title, and one for the numerical code for that particular code section. So say if I select "Kidnapping", it prepopulates the text box below it with "11-5-77", for example.
The method I've been using for, oh, about the last hour now, is:
If AWOffenseTitle.Text = "Kidnapping" Then
AWCN.Text = "11-5-77"
ElseIf AWOffenseTitle.Text = "False Imprisonment" Then
AWCN.Text = "11-5-78"
With AWOffenseTitle being the combo box name, and AWCN being the text box name. While this has proved to work perfectly well so far, I'm sure you can imagine with hundreds of offense titles, this is going to take a ridiculously long time. Well, I finally found a spreadsheet with offense titles and their respective title codes. What I'm looking to do is create two text files within a folder in the local directory "Offenses". One with a vertical list of offenses, and one with a vertical list of offense code numbers that populate the same lines in each. What I'm looking to do is populate the combo box with the contents of text file one (which I can do already), but then selecting an offense title will read the second text file and display it's proper title code. That's what has me at a loss. I'm relatively well-versed with vb.NET, but I'm not an expert by any means.
I'm hoping someone here will be able to provide a code example and explain it to me line-by-line so I can gain a better understanding. I want to get more proficient with VB although it's not so popular anymore. I've been using VB since 6.0, but not on a regular basis. More on a sporadic project kind of basis.
I really appreciate any assistance anyone might be able to provide, and if you need more information, I'd be glad to answer any questions. I tried to be as thorough as I could.
Thank you in advance!
First, you need to retrieve your data. I demonstrated using an Sql Server database containing a table named Offenses with columns named OffenseTitle and OffenseCode. You will have to change this code to match your situation.
Private Function GetOffenseData() As DataTable
Dim dt As New DataTable
Using cn As New SqlConnection("Your connection string"),
cmd As New SqlCommand("Select OffenseTitle, OffenseCode From Offenses;")
cn.Open()
dt.Load(cmd.ExecuteReader)
End Using
Return dt
End Function
As the Form loads, set the properties of the ComboBox. DisplayMember matches the name of the title column and ValueMember is the name of the code column.
Private Sub Form1_Load(sender As Object, e As EventArgs) Handles MyBase.Load
Dim dt = GetOffenseData()
ComboBox1.DisplayMember = "OffenseTitle"
ComboBox1.ValueMember = "OffenseCode"
ComboBox1.DataSource = dt
End Sub
Then when the selected item in the combo changes, just set the .Text property of TextBox to the SelectedValue in the combo and your code appears.
Private Sub ComboBox1_SelectionChangeCommitted(sender As Object, e As EventArgs) Handles ComboBox1.SelectionChangeCommitted
TextBox1.Text = ComboBox1.SelectedValue.ToString
End Sub
There are other ways to do this if your data source is other than a database. Please advise if you need additional help.
In addition to HardCode's comment and Mary's detailed answer, I can only add an answer that's somewhere in between them.
It might be the case, that the information is not taken from a database, but from another source, like a text/data file or a web service. So it might be useful to create an abstraction for the data source you actually use.
First, I create a class or struct that will hold the data for each combo box item.
Class Offense
Public ReadOnly Property Title As String
Public ReadOnly Property Code As String
Public Sub New(title As String, code As String)
Me.Title = title
Me.Code = code
End Sub
End Class
Next, you need a method that retrieves a list of offenses that you can bind to your combo box. It's entirely up to you how you fill/fetch the offenses list. I have simply hard coded your two values here.
Private Function GetOffenseData() As List(Of Offense)
Dim offenses As New List(Of Offense)
offenses.Add(New Offense("Kidnapping", "11-5-77"))
offenses.Add(New Offense("False Imprisonment", "11-5-78"))
Return offenses
End Function
At a certain moment (probably in your form's Load event handler), you need to initialize your combo box. Just like Mary did, I use data binding.
Private Sub Form1_Load(sender As Object, e As EventArgs) Handles MyBase.Load
AWOffenseTitle.DropDownStyle = ComboBoxStyle.DropDownList
AWCN.ReadOnly = True
AWOffenseTitle.DisplayMember = NameOf(Offense.Title)
AWOffenseTitle.ValueMember = NameOf(Offense.Code)
AWOffenseTitle.DataSource = GetOffenseData()
End Sub
Note that I use the NameOf operator to get the desired property names of the Offense class. If you ever decide to rename the properties of your Offense class, you will be able to easily detect where they are used, since the compiler will complain if your code still uses the wrong property names somewhere.
Finally, the app needs to react to combo box value changes, so that the text box will show the corresponding offense code. Mary used an event handler for the SelectionChangeCommitted event, but I use a handler for the SelectedIndexChanged event instead:
Private Sub AWOffenseTitle_SelectedIndexChanged(sender As Object, e As EventArgs) Handles AWOffenseTitle.SelectedIndexChanged
AWCN.Text = AWOffenseTitle.SelectedValue
End Sub
(Up to now, I was not aware of the SelectionChangeCommitted event of the ComboBox control. I will need to look into this event to see if it is actually a better choice for this scenario, but I found that the SelectedIndexChanged event does the job just fine, so for now I sticked with that event, since I am more familiar with it.)
The basic problem is I have a form (Form A) that opens another form (Form B for now) to edit information in Form A. When Form B is done, it should refresh the information in Form A.
To accomplish this, I create in Form B
Public Event Saved(sender As Object, e As EventArgs)
And then call it with
RaiseEvent Saved(sender, e)
I know that the RaiseEvent line is executing (if I set breakpoints and step over the debugger lands on it), but then the line in Form A that should be picking up the event
Private Sub frmContactPrefixDel_Saved(sender As Object, e As EventArgs) Handles frmContactPrefixDel.Saved
Where frmContactPrefixDel points to Form B doesn't pick up the event and execute it's lines. If I set a breakpoint on that line it doesn't even get to that sub at all. Any obvious problems? I'm new to object oriented programming, but I can't see where I've gone wrong. It seems simple to me. Also, intellisense in Visual Studio 2015 is picking up the .Saved on the end of frmContactPrefixDel so I don't think it's a scope issue.
I realize I'm making assumptions here as someone new to the game. Feel free to ask questions.
I'm working on visual studio 2015 and I'm working on a classic subscribing form.
I want to generate error labels when the user type wrong password, the wrong pseudo, etc. But I can work on it myself.
But when I write those error labels and set their visible at false in "Dev mode", I have to juxtapose those labels if I want my labels at the same place, and it's not what I want when I have many errors to manage on one textBox for example.
Is there a solution to gererate those labels, without write them before playing with hide() or show() ?
Here is the screenshot in order to illustrate my problem.
It's not really a problem itself, but It's not practical when I'm develop many errors.
Sorry for my english, I hope you understood my problem, I can give you more details =)
Have a nice day full of code !
Here the button code:
Private Sub Button1_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles Button1.Click
If TextBox1.Text <> "Password" Then
Label2.Text = "Your answer is wrong"
End If
End Sub
This is what it looks like:
Newbie here :)
In order to achieve a transparency-type effect for pictureboxcharacter1 on the background, I have set pictureboxbackground1 as its parent.
this works fine.
For the second picturebox (on the same form) I tried the same thing and set pictureboxbackground2 as its parent so it would look transparent over pictureboxbackground2. However when I debug the application pictureboxcharacter2 disappears and only pictureboxbackground2 is visible.
the code I have is:
Private Sub Form2_Load(sender As System.Object, e As System.EventArgs) Handles MyBase.Load
Me.pictureboxcharacter1.Parent = Me.pictureboxbackground1
Me.pictureboxcharacter2.Parent = Me.pictureboxbackground2
End Sub
Really strange: if I put pictureboxcharacter2 on pictureboxbackground1 in the designer tab, while debugging it shows up on picturebackground2 and transparent (like how I wanted it to be)??
Does anyone know what's going on at all?
Please I'm NEED any help I could get
Is pictureboxcharacter1 and pictureboxcharacter2 one over other ? If so try making the one be other's parent.
Have a play with bring to front option and see if that works.
I use the LostFocus Event in vb.net to check the validity of a field for the name.
After this field a have another one which is the for the password validity, and i'm handilg the same event in order to check the password.
My problem comes when i run the (name) lost focus, runs the code inside the sub and after that automatically goes to the password_lostfocus which brings me alot of troubles.
That happens even i use the error provider which works fine and bring to me the error with the red flashing.After that i put the command (name_textbox.focus), which logically has to bring the control in the name_textbox.. But NO.. the control goes to the Password_textbox sub automatically.
Please see my sub
Private Sub UsernameTextBox_LostFocus(ByVal sender As Object, ByVal e As System.EventArgs) Handles UsernameTextBox.LostFocus
Select Case DB_Access.IfExistUser(UsernameTextBox.Text, sender, e)
Case True
PasswordTextBox.Focus()
Case False
ErrorProvider1.SetError(UsernameTextBox, "Ο χρήστης ΔΕΝ υπάρχει παρακαλώ καλέστε τον Administrator")
Beep()
UsernameTextBox.Text = ""
UsernameTextBox.Focus()
End Select
End Sub
Please if anyone have seen this issue and face it, assist me.
Excuse me for some Greek characters they are meaningless, they are comments
Well finally i found that.
In order to handle the Login Form as it give it from visual studio 2010 you need to do it in only one sub (Lost Focus) and that is only the password_LostFocus.
I believe the particular form is meant to be like that.
Any way i solve the issue and if anybody needs assistance on that just "asc a question"