I am stating VB and since it is so close to VBScript I have been having fun with it. But now I have come across the "Checkboxlist".
My boss saw me making a Windows Forms Application and asked me to make him a interface (GUI) for one of his batch files. In the batch you start by choosing between lines 1 through 10 and it does the rest. So I made a Checkboxlist and made check-boxes going from 1 to 10. Now I am not sure how to tell it that when I click a button a if statement looks at what has been checked and take to appropriate action.
I think i am suppose to start with something like
If CheckedListBox1.Items() = True then
But i know this does not work.
Anything thing will help.
Thank you.
It sounds like you're looking for the ItemCheck event. This event is fired when the checked state of an item changes.
Private Sub HandleCheckedListBox1ItemCheck(sender As Object, e As ItemCheckEventArgs) Handles CheckedListBox1.ItemCheck
Dim item As Object = Me.CheckedListBox1.Items.Item(e.Index)
Dim text As String = Me.CheckedListBox1.GetItemText(item)
Select Case e.CurrentValue
Case CheckState.Unchecked
'...
Case CheckState.Checked
'...
Case CheckState.Indeterminate
'...
End Select
End Sub
Or iterate all checked items:
Private Sub HandleButton1Click(sender As Object, e As EventArgs) Handles Button1.Click
For Each item As Object In Me.CheckedListBox1.CheckedItems
Dim text As String = Me.CheckedListBox1.GetItemText(item)
'...
Next
End Sub
Related
I am having some problems lately with selecting ALL items(ONLY once!) from a listbox and adding them to a listview. I am using a backgroundworker to handle this task due to big content the listview will contain and to avoid GUI freezing while performing this task.
Ok, so here is the BackgroundWorker_ProgressChanged code :
For Each item In ListBox3.SelectedItems
listView1.Items.Add(ListBox3.SelectedItem, ImageList1.Images.Count - 1).SubItems.Add("Test")
ListView1.Items("Test").SubItems.Add("")
Next
For Each item As ListViewItem In ListView1.SelectedItems
Next
End Sub
The above written code displays items in listview, but ONLY if the user selects a certain item from the Listbox3 and displays infinite times the selected items from the listbox, I want it display ONLY ONCE all selected items from the Listbox, in the Listview. I want to select ALL items automatically, without user intervention, I have tried several methods which have failed.
Can someone please provide a solution to this issue ? Thanks.
I just tested and it seems that getting items from a ListBox on a secondary thread is not an issue, so I was wrong about that. Adding/setting items definitely would be though, so you'd need to add the items to the ListView on the UI thread. Here's some example code that just worked for me:
Private Sub Button1_Click(sender As Object, e As EventArgs) Handles Button1.Click
BackgroundWorker1.RunWorkerAsync()
End Sub
Private Sub BackgroundWorker1_DoWork(sender As Object, e As DoWorkEventArgs) Handles BackgroundWorker1.DoWork
Dim outputItems As New List(Of ListViewItem)
For Each inputItem As String In ListBox1.Items
outputItems.Add(New ListViewItem(inputItem))
Next
e.Result = outputItems
End Sub
Private Sub BackgroundWorker1_RunWorkerCompleted(sender As Object, e As RunWorkerCompletedEventArgs) Handles BackgroundWorker1.RunWorkerCompleted
Dim items = DirectCast(e.Result, List(Of ListViewItem))
ListView1.Items.AddRange(items.ToArray())
End Sub
The problem is all the screen redrawing. I am guessing you may not need a background worker if you limit the screen redraw.
I used a list for the ListViewItems since I don't know how many there will be. Had to convert the list to an array to use .AddRange.
As a matter of fact just the .BeginUpdate and .EndUpdate might speed things up enough to be acceptable.
I am not sure about the use of ImageList so you might have to play around with that.
Private Sub OpCode()
Dim items = From itm In ListBox1.Items 'or ListBox1.SelectedItems
Select CStr(itm)
Dim lvItems As New List(Of ListViewItem)
Dim imageIndex As Integer = ImageList1.Images.Count - 1
For Each item In items
Dim lvItem As New ListViewItem(item, imageIndex)
lvItems.Add(lvItem)
Next
'ListView1.BeginUpdate()
ListView1.Items.AddRange(lvItems.ToArray)
'ListView1.EndUpdate()
End Sub
I am trying to use the panel and buttons to load 2 different forms along with entity framework and ado model stuff. I am trying to load the 2nd form this picture, using the codes running on the first form since they have the same table. but what happen is whenever I close the 2nd form and try to switch on the second user from this form(driverlist), I am still getting the results that I created before on the first user, I kinda think that the 2nd form is not being loaded although I put some code:
Private Sub DriverLicense_Load(sender As Object, e As EventArgs) Handles MyBase.Load
Dim user_id As Integer = Driverlist.tbxUser_id.Text
Driverlist.db = New [Emme_Subic_Transport_Corporation_Payroll].EmmeSubicEntities
Driverlist.db.UserDetails.Where(Function(c) c.isDeleted <> 1 And c.Id = user_id).Load()
UserDetailBindingSource.DataSource = Driverlist.db.UserDetails.Local
If Driverlist.tbxUser_id.Text.Count < 1 Then
MessageBox.Show("Please Select an Employee ID First", "Information", MessageBoxButtons.OK, MessageBoxIcon.Information)
Drivertest.Panelswitch(Driverlist)
Else
Me.Show()
End If
End Sub
Private Sub DriverLicense_Activated(sender As Object, e As EventArgs) Handles Me.Activated
Dim user_id As Integer = Driverlist.tbxUser_id.Text
Driverlist.db = New [Emme_Subic_Transport_Corporation_Payroll].EmmeSubicEntities
Driverlist.db.UserDetails.Where(Function(c) c.isDeleted <> 1 And c.Id = user_id).Load()
UserDetailBindingSource.DataSource = Driverlist.db.UserDetails.Local
End Sub
I binded the 2nd form through other resources of data binding from the properties but still on the same resources as the first form. Im pretty new to this so please stop putting negatives on my questions. If you think I am bad at this, I know and I am sorry. by the way this is the code from the buttons and panel if that helps. Thanks everyone.
Sub Panelswitch(Panel As Form)
PanelControl.Controls.Clear()
Panel.TopLevel = False
PanelControl.Controls.Add(Panel)
Panel.Show()
End Sub
Private Sub Btntest_Click(sender As Object, e As EventArgs) Handles Btntest.Click
Panelswitch(Driverlist)
End Sub
Private Sub Btntest2_Click(sender As Object, e As EventArgs) Handles btntest2.Click
Panelswitch(DriverLicense)
End Sub
There are number of things I would avoid, just looking at your pictures, but that goes beyond your question.
Secondly, agreed with the comment, you should revise your question further (I see you tried, but still, it's neither complete or clear).
If I understand correctly, you have container PanelControl, which you fill either with a form DriverList or DriverLicence. I just want to make sure - are you sure you have your instances corectly set? Because I would expect that the switch would act only for displaying correct form, but should behave differently for the [persistent] list DriverList and DriverLicence, which should be probably a new instance every time you want to add a licence. But this code is not shown, just guessing the problem might be along those lines. There are quite few design possibilities, I guess.
Simplified, the point is:
Private Sub Btntest2_Click(sender As Object, e As EventArgs) Handles btntest2.Click
Dim DriverLicenceInstance as new DriverLicence
Panelswitch(DriverLicenseInstance)
End Sub
I also think, that you might have your binding set incorrectly for the 2nd form, the DriverLicence. I'm not proficient in .NET binding, but it seems to me that you declare the bindings as two separate things (comes from the copying the code?). But what you probably need to do is to use the same binding source for both parts. See here: A-Detailed-Data-Binding-Tutorial.
I need to set a minimum length for a password that can be used in a textbox and then set a label which will say if it meets the minimum number of characters required. I know how to set the limit of characters, what I can't do is the part where it will show in a label as soon as I leave the textbox. I was thinking I need to use an event, like maybe Leave or LostFocus, but it's not working. Please help :(
Ok, There are plenty of ways to do what you want to achieve. I personally like to a separate subroutine; if you need to change one thing, you wont have to edit every single event that has the same codeFrom what I can understand, something like this should help get you on your way. Basically, we just setup a subroutine that will check to see if textbox1.text's length is more than five and we trigger the subroutine by using events such as a button click of if the textbox is clicked off.
Private Sub Button1_Click(sender As Object, e As EventArgs) Handles Button1.Click ''save button
checkPassword(TextBox1.Text)
End Sub
Private Sub TextBox1_Leave(sender As Object, e As EventArgs) Handles TextBox1.Leave
checkPassword(TextBox1.Text)
End Sub
Private Sub checkPassword(password As String)
If Not password.Length > 5 Then
Label1.Text = "The password must be more than 5 charcharacters"
TextBox1.Clear()
Else
Label1.Text = "Password accepted"
End If
End Sub
I'm migrating an application from VB6 to VB.Net and I found a change in the behavior of the ListBox and I'm not sure of how to make it equal to VB6.
The problem is this:
In the VB6 app, when the ListBox is focused and I type into it, the list selects the element that matches what I type. e.g. If the list contains a list of countries and I type "ita", "Italy" will be selected in the listbox.
The problem is that with the .Net version of the control if I type "ita" it will select the first element that starts with i, then the first element that starts with "t" and finally the first element that starts with "a".
So, any idea on how to get the original behavior? (I'm thinking in some property that I'm not seeing by some reason or something like that)
I really don't want to write an event handler for this (which btw, wouldn't be trivial).
Thanks a lot!
I shared willw's frustration. This is what I came up with. Add a class called ListBoxTypeAhead to your project and include this code. Then use this class as a control on your form. It traps keyboard input and moves the selected item they way the old VB6 listbox did. You can take out the timer if you wish. It mimics the behavior of keyboard input in Windows explorer.
Public Class ListBoxTypeAhead
Inherits ListBox
Dim Buffer As String
Dim WithEvents Timer1 As New Timer
Private Sub ListBoxTypeAhead_KeyDown(sender As Object, _
e As System.Windows.Forms.KeyEventArgs) Handles Me.KeyDown
Select Case e.KeyCode
Case Keys.A To Keys.Z, Keys.NumPad0 To Keys.NumPad9
e.SuppressKeyPress = True
Buffer &= Chr(e.KeyValue)
Me.SelectedIndex = Me.FindString(Buffer)
Timer1.Start()
Case Else
Timer1.Stop()
Buffer = ""
End Select
End Sub
Private Sub ListBoxTypeAhead_LostFocus(ByVal sender As Object, _
ByVal e As System.EventArgs) Handles Me.LostFocus
Timer1.Stop()
Buffer = ""
End Sub
Public Sub New()
Timer1.Interval = 2000
End Sub
Private Sub Timer1_Tick(sender As Object, e As System.EventArgs) Handles Timer1.Tick
Timer1.Stop()
Buffer = ""
End Sub
End Class
As you probably know, this feature is called 'type ahead,' and it's not built into the Winform ListBox (so you're not missing a property).
You can get the type-ahead functionality on the ListView control if you set its View property to List.
Public Function CheckIfExistInCombo(ByVal objCombo As Object, ByVal TextToFind As String) As Boolean
Dim NumOfItems As Object 'The Number Of Items In ComboBox
Dim IndexNum As Integer 'Index
NumOfItems = objCombo.ListCount
For IndexNum = 0 To NumOfItems - 1
If objCombo.List(IndexNum) = TextToFind Then
CheckIfExistInCombo = True
Exit Function
End If
Next IndexNum
CheckIfExistInCombo = False
End Function
I have a custom form, B. B is created by A, which has a handle to B.VisibleChanged.
B only has an OK and Cancel button on it, and I want to do some logic when OK is hit.
B's OK button is dealt with like this:
Me.Result = Windows.Forms.DialogResult.OK
Me.Hide()
The code in A is properly hit and run, but it never hides B. When I check the values of the properties on B, it shows me Visible = False.
Does anyone have any suggestions as to the possible cause of this issue?
Edit
This form was shown using the Show() command, as I'm making a later call to have the form flash using FlashWindow().
Not exactly sure about your question.
why not use me.Close() instead of me.Hide?
Is it OK to have multiple instances of B at a time? If not, go for ShowDialog.
If you can rephrase the question, someone can probably resolve your problem.
I suppose you want to display a messagebox with an ok & cancel button. Instead of using a form use a mesagebox.
eg:
DialogResult dgResult = MessageBox.Show("Click Yes or No", "Test App", MessageBoxButtons.OKCancel, MessageBoxIcon.Information);
if (DialogResult.OK == dgResult)
{
//Do what you want.
}
else
{
//Do nothing.
}
If you are going to use a form, to do that & wanted to modify the parent's form, it would be advisable to use delegates to prevent form B from modifying form A's variables.
Else: (Not recommended)
Declare form B as a member variable of form A.
when required instantiate form B.
do B.ShowDialog();
internally in OK & cancel do this.dispose();
Again when you need form B just instantiate. re - instantiation will not be too much of an overhead if you dont call it very often.
But if you only need OK Cancel, use message box instead.
The show/hide approach works for me:
Public Class frmViewChild ' your form A
Private WithEvents _edit As frmEdit
'code
Private Sub editCell()
Dim PKVal As String
Dim PKVal2 As String
Dim fieldOrdinalPos As Integer
Dim isLastField As Boolean
If _edit Is Nothing Then
_edit = New frmEdit
_edit.MdiParent = Me.MdiParent
End If
'code
_edit.init(<params>)
If Not _edit.isNothing Then
_edit.Show()
_edit.WindowState = FormWindowState.Maximized
_edit.BringToFront()
End If
End Sub
'code
Private Sub _edit_VisibleChanged(ByVal sender As Object, ByVal e As System.EventArgs) Handles _edit.VisibleChanged
If Not _edit.Visible Then
WindowState = FormWindowState.Maximized ' revert after closing edit form
End If
End Sub
Public Class frmEdit ' your form B
Private Sub btnOK_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles btnOK.Click
Dim ret As Integer
doOK(ret)
If ret > -1 Then ' no error
Me.Hide() ' close form, but didn't cancel
End If
End Sub
HTH