I have a collection of buttons on a panel, I want to be able to build a collection of those buttons and then sort the buttons by the text on the button. However, I am stuck. This is what I have so far, but I can't figure out how to sort.
Private Sub Button4_Click(sender As Object, e As EventArgs) Handles Button4.Click
Dim btn1 As Control
Dim btnArray(0 To 3) As Button
btnArray(0) = btnAll
btnArray(1) = btnWine
btnArray(2) = btnBeer
btnArray(3) = btnNonAlcoholic
For Each btn1 In btnArray
Next
End Sub
You can use a simple manual bubble sort:
Dim Changed as Boolean = False
Do
Changed = False
For i = 0 to btnArray.Count - 2
If btnArray(i).Text > btnArray(i+1).Text Then '< > work for strings as well and they check 'position' in the alphabet. So "A" < "B" and so on
'If order is wrong, switch the two buttons
Dim temp as Button = btnArray(i+1)
btnArray(i + 1) = btnArray(i)
btnArray(i) = temp
Changed = True
End If
Next
'Do this until no more switches are necessary
Loop Until Changed = False
This will order your buttons and is reasonably fast for low numbers of buttons. You could use a list and a custom IComparer object as well and simply call List.Sort with the custom comparer.
See here for example implementations of this approach for a similar problem: http://msdn.microsoft.com/en-us/library/cfttsh47%28v=vs.110%29.aspx
Using LINQ:
btnArray = btnArray.OrderBy(Function(btn) btn.Text).ToArray
Related
This is my first question in this community and I'd like some help with a school project I am doing.
I am implementing a turn system where every time you select a method to score a variable called turn increases by one so that the appropriate label is changed to the points you got that turn.
This is an example of the Ones option to score which checks all the dice and adds up all the dice which have the value one, when the Ones button is pressed it should update the current turn with the points gained. At the moment it only updates the first turns score. The second and third images are of the changes I tried making which don't work.
[Ones][1]
[Ones changed][2]
[Ones error][3]
```
Private Sub btnOnes_Click(sender As Object, e As EventArgs) Handles btnOnes.Click
Dim Nums(4) As Integer
Nums(0) = RandomNum1
Nums(1) = RandomNum2
Nums(2) = RandomNum3
Nums(3) = RandomNum4
Nums(4) = RandomNum5
For i = 0 To 4
If Nums(i) = 1 Then
OnesScore += 1
End If
Next
lblTurnValue1.Text = OnesScore
Turn += 1
btnOnes.Enabled = False
End Sub
Private Sub btnOnes_Click(sender As Object, e As EventArgs) Handles btnOnes.Click
Dim Nums(4) As Integer
Nums(0) = RandomNum1
Nums(1) = RandomNum2
Nums(2) = RandomNum3
Nums(3) = RandomNum4
Nums(4) = RandomNum5
For i = 0 To 4
If Nums(i) = 1 Then
OnesScore += 1
End If
Next
lblTurnValue1(Turn).Text = OnesScore
Turn += 1
btnOnes.Enabled = False
End Sub
Another problem I have been having is automatically updating labels as I want to make a Newbie mode for my Yahtzee game which displays the numbers beside each option to score so you know what score you are going to get before you choose.
I can't use the Ones button for clicking to represent the score because it's used for scoring the points and whenever I try double click on the label to show its code in Visual Studio it only updates in game when the person clicks the number to show their score which is not what I desire.
[Ones label][4]
Private Sub lblOnes_Click(sender As Object, e As EventArgs) Handles lblOnes.Click
lblOnes.Text = OnesScore
End Sub
In short I want to learn how to use variables within names of objects to allow for the right one to be chosen and how to update labels automatically instead of having to click them. Any resources you can provide to further my understanding of VB.NET is really helpful.
Thanks.
[1]: https://i.stack.imgur.com/zUQM6.png
[2]: https://i.stack.imgur.com/c5nJe.png
[3]: https://i.stack.imgur.com/Y3gUE.png
[4]: https://i.stack.imgur.com/BnwZ8.png
In visual basic I want to be able to access a button's name using the number stored in a variable.
For example if I have 24 buttons that are all named 'Button' with the numbers 1, 2, 3... 22, 23, 24 after it. If I want to then change the text in the first eight buttons how would I do that.
Here's my example to help show what I mean:
For i = 1 to 8
Button(i).text = "Hello"
Next
The proposed solutions so far will fail if the Buttons are not directly contained by the Form itself. What if they are in a different container? You could simple change "Me" to "Panel1", for instance, but that doesn't help if the Buttons are spread across multiple containers.
To make it work, regardless of the Buttons locations, use the Controls.Find() method with the "searchAllChildren" option:
Private Sub Button1_Click(sender As Object, e As EventArgs) Handles Button1.Click
Dim ctlName As String
Dim matches() As Control
For i As Integer = 1 To 8
ctlName = "Button" & i
matches = Me.Controls.Find(ctlName, True)
If matches.Length > 0 AndAlso TypeOf matches(0) Is Button Then
Dim btn As Button = DirectCast(matches(0), Button)
btn.Text = "Hello #" & i
End If
Next
End Sub
For index As Integer = 1 To 8
CType(Me.Controls("Button" & index.ToString().Trim()),Button).Text = "Hello"
Next
Use LINQ and you're good to go:
Dim yourButtonArray = yourForm.Controls.OfType(of Button).ToArray
' takes all controls whose Type is Button
For each button in yourButtonArray.Take(8)
button.Text = "Hello"
Next
Or
Dim yourButtonArray = yourForm.Controls.Cast(of Control).Where(
Function(b) b.Name.StartsWith("Button")
).ToArray
' takes all controls whose name starts with "Button" regardless of its type
For each button in yourButtonArray.Take(8)
button.Text = "Hello"
Next
In any case, .Take(8) will iterate on the first 8 items stored inside yourButtonArray
I have a setup in my code where there is a datagridview. For each row I have a combo box cell that I have a separate combo box cell since I want a different selection of items for each cell.
Problem : The cell only drops down when the arrow is double clicked. How can I change the cell formatting, or possibly a cell click event, so that the cell response to just one click?
Here's my cell creation code. Frankly, I didn't start any other code since I didn't know what event to touch or call. Is there a property I can edit?
Code:
'add items to combobox list
Dim comboCell As New DataGridViewComboBoxCell
comboCell.FlatStyle = FlatStyle.Flat
Dim resolutionList As New List(Of cmbStruct)
Dim currentResIndex As Integer = 0
'create list of resolutions
For j As Integer = 0 To resolutions.Length - 1
Dim resClass As New cmbStruct
resClass.Name = resolutions(j)
resClass.ID = resolutions(j)
resolutionList.Add(resClass)
comboCell.Items.Add(resolutions(j))
Next
'set combocell values
comboCell.DisplayMember = "Name"
comboCell.ValueMember = "ID"
'set the default value to the current resolution index
Try
comboCell.Value = resolutions(currentResIndex)
Catch ex As Exception
End Try
comboCell.ValueType = GetType(cmbStruct)
comboCell.DataSource = resolutionList
editCameraTable("Resolution", i) = comboCell
Next
Change the EditMode property:
DataGridView1.EditMode = DataGridViewEditMode.EditOnEnter
There seems to be a nearly identical question and a very good answer. It involves using the click_event. Here is the link:
How to manually drop down a DataGridViewComboBoxColumn?
In the link:
Private Sub cell_Click(ByVal sender As System.Object, ByVal e As DataGridViewCellEventArgs) Handles DataGridView1.CellClick
DataGridView1.BeginEdit(True)
If DataGridView1.Rows(e.RowIndex).Cells(ddl.Name).Selected = True Then
DirectCast(DataGridView1.EditingControl, DataGridViewComboBoxEditingControl).DroppedDown = True
End If
End Sub
i am trying to draw sort arrows on list view column header along with the default visual styles
so far i have got this
Private Sub List_DrawColumnHeader(sender As Object, e As DrawListViewColumnHeaderEventArgs) Handles List.DrawColumnHeader
e.DrawDefault = True
If e.ColumnIndex = selectedIndex Then
e.Graphics.DrawImage(ImageList1.Images(1), CType(e.Bounds.Left + e.Bounds.Width / 2, Single) - 5, -2)
End If
End Sub
but the visual style is drawn over the arrow somehow
so i figured i could try this :
Private Sub List_DrawColumnHeader(sender As Object, e As DrawListViewColumnHeaderEventArgs) Handles List.DrawColumnHeader
e.DrawDefault = True
If lastDrawn.ColumnIndex = selectedIndex Then
e.Graphics.DrawImage(ImageList1.Images(1), CType(lastDrawn.Bounds.Left + lastDrawn.Bounds.Width / 2, Single) - 5, -2)
End If
lastDrawn=e
End Sub
and it draws the arrow when the next corresponding column is being drawn
but with this i cant get it to draw for the last column
Screenshots:
In order to use the .NET build in solution for showing a custom icon for a list view column header you need to:
create an ImageList
add three images (up / down arrow and empty) to it
bind the image list to the ListView control
bind to the ColumnClick event of the ListView control
when sorting the columns set the ImageKey property of the currently sorted column depending on the sorting direction
This example class (a simple form) shows how to set the images correctly not using custom drawing for the ListView header columns.
It does not implement any sort! (how to implement a ListViewSorter is shown in this MSDN article)
You need to implement a custom ListView-Sorter class and retrieve the image or the image key from it, after a column is sorted.
Public Class SimpleForm
Inherits Form
Private sortItems = New ImageList()
Dim lv As ListView = New ListView()
Dim so = System.Windows.Forms.SortOrder.Ascending
Public Sub New()
' create columns, items and ListView
Dim columns = New List(Of ColumnHeader)
Dim c1 = New ColumnHeader()
c1.Name = "c1"
c1.Text = "Name"
Dim c2 = New ColumnHeader()
c2.Name = "c2"
c2.Text = "Type"
columns.Add(c1)
columns.Add(c2)
Dim items = New List(Of ListViewItem)
Dim i1 = New ListViewItem("Terminator")
i1.SubItems.Add("T1000")
Dim i2 = New ListViewItem("Terminator")
i2.SubItems.Add("T10")
Dim i3 = New ListViewItem("J.C.")
i3.SubItems.Add("Human")
items.Add(i1)
items.Add(i2)
items.Add(i3)
' init and bind column click
lv.Columns.AddRange(columns.ToArray())
lv.Items.AddRange(items.ToArray())
lv.SmallImageList = sortItems
lv.View = View.Details
lv.Dock = DockStyle.Fill
Controls.Add(lv)
AddHandler lv.ColumnClick, AddressOf clickEventHandler
' init images list
sortItems.TransparentColor = System.Drawing.Color.Transparent
sortItems.Images.Add("up", Image.FromFile("d:\temp\32\arrow_up.gif"))
sortItems.Images.Add("down", Image.FromFile("d:\temp\32\arrow_down.gif"))
sortItems.Images.Add("empty", Image.FromFile("d:\temp\32\check.gif"))
End Sub
Private Sub clickEventHandler(ByVal o As Object, ByVal e As ColumnClickEventArgs)
' Implement a custom ListViewItemSorter and fetch the icon from it!
' Set the ListViewItemSorter property to a new ListViewItemComparer
' object. Setting this property immediately sorts the
' ListView using the ListViewItemComparer object.
' THIS CODE SHOWS ONLY HOW TO SET THE SORT ICON!
For i As Integer = 0 To lv.Columns.Count - 1
If (i = e.Column) Then
Select Case (so)
Case System.Windows.Forms.SortOrder.Ascending
lv.Columns(i).ImageKey = "up"
so = System.Windows.Forms.SortOrder.Descending
Case System.Windows.Forms.SortOrder.Descending
lv.Columns(i).ImageKey = "down"
so = System.Windows.Forms.SortOrder.Ascending
Case Else
lv.Columns(i).ImageKey = "empty"
so = System.Windows.Forms.SortOrder.None
End Select
Else
lv.Columns(i).ImageKey = "empty"
End If
Next i
End Sub
End Class
The output looks like this:
I have managed to filter my combobox so it filters and displays the correct records ie when A is typed all A records show, B is typed all B records show and so on. However it would it be possible to have a message box to display when no records is found in the combobox?
The coding i have so far is :-
Private Sub cmblogged_KeyPress(sender As Object, e As KeyPressEventArgs) Handles cmblogged.KeyPress
If Char.IsControl(e.KeyChar) Then Return
With Me.cmblogged
Dim ToFind As String = .Text.Substring(0, .SelectionStart) & e.KeyChar
Dim Index As Integer = .FindStringExact(ToFind)
If Index = -1 Then Index = .FindString(ToFind)
If Index = -1 Then Return
.SelectedIndex = Index
.SelectionStart = ToFind.Length
.SelectionLength = .Text.Length - .SelectionStart
e.Handled = True
End With
End Sub
Achieving what you want with your code is straightforward, just convert If Index = -1 Then Return into:
If Index = -1 Then
MessageBox.Show("Not Found.")
Return
End If
In any case, note that there is an in-built functionality in ComboBox performing the same action which your code does right now: AutoCompleteMode different than None and AutoCompleteSource set to ListItems. Logically, you can evolve your code to perform much more complex actions (what I guess that is the case), but I preferred to highlight this issue just in case.