I have a form on which in the Paint event some labels with some information are drawn inside a panel - this works fine. However I would like to have the text on the labels being changed depending on the value of a Trackbar that is placed on the same form. This is the Trackbar-Scroll Event which should refresh the whole form:
Private Sub TrackBar1_Scroll(sender As Object, e As EventArgs) Handles TrackBar1.Scroll
Me.Refresh()
End Sub
And this is the code that draws the labels on the form:
Public Sub Form_Paint(sender As Object, e As PaintEventArgs)
For i = 0 To 10
Dim tb As New Label
tb.Name = "tb" & CStr(i)
If Me.TrackBar1.Value = 1 Then tb.Text = "sometext"
If Me.TrackBar1.Value = 0 Then tb.Text = "anothertext"
tb.Location = New Point(i, i * 2)
Me.Panel1.Controls.Add(tb)
Next
End Sub
However no matter in what state the trackbar is the text displayed in the labels is alaways "anothertext". The Paint event is triggered as far as I can tell when I change the value of the trackbar but how can I also force the labels to update?
Just add the labels once. Separate the creating and changing logic into two methods
Private prefix As String = "tb"
Private factor As Integer = 10
Private Sub Form1_Load(sender As Object, e As EventArgs) Handles MyBase.Load
addLabels()
changeLabels()
End Sub
Private Sub addLabels()
For i = 0 To 10
Dim tb As New Label()
tb.Name = prefix & CStr(i)
tb.Location = New Point(factor * i, factor * i * 2)
Me.Panel1.Controls.Add(tb)
Next
End Sub
Private Sub changeLabels()
For i = 0 To 10
Dim tb As Label = CType(Panel1.Controls(prefix & CStr(i)), Label)
If Me.TrackBar1.Value = 1 Then tb.Text = "sometext"
If Me.TrackBar1.Value = 0 Then tb.Text = "anothertext"
Next
End Sub
Now, in TrackBar1_Scroll, you can just change them (instead of recreating them)
Private Sub TrackBar1_Scroll(sender As Object, e As EventArgs) Handles TrackBar1.Scroll
changeLabels()
End Sub
Since the label value depends on the TrackBar value, there is no reason to update them in Paint, which happens more frequently than the TrackBar is updated.
Adding new Labels and removing old Labels in Paint seems like a lot of extra processing.
I believe you need to set the LargeChange property of the TrackBar as a Scroll Event is considered a large change, but LargeChange defaults to 0, thus when you scroll the Value is only increasing/decreasing by 0, Leaving it at 0
Related
I am looking for a way to draw multiple custom lines in my checkbox. I have the following code:
Private Sub Form1_Load(sender As Object, e As EventArgs) Handles MyBase.Load
ComboBox1.DrawMode = System.Windows.Forms.DrawMode.OwnerDrawFixed
ComboBox1.Size = New System.Drawing.Size(100, 20)
ComboBox1.DropDownWidth = 100
ComboBox1.TabIndex = 0
ComboBox1.DropDownStyle = System.Windows.Forms.ComboBoxStyle.DropDownList
ComboBox1.Items.Add("test1")
ComboBox1.Items.Add("test2")
ComboBox1.Items.Add("test3")
AddHandler ComboBox1.DrawItem, AddressOf ComboBox1_DrawItem
End Sub
Private Sub ComboBox1_DrawItem(sender As Object, e As System.Windows.Forms.DrawItemEventArgs)
e.DrawBackground()
Dim black_pen As System.Drawing.Pen = New System.Drawing.Pen(System.Drawing.Color.Black, 2)
black_pen.DashStyle = System.Drawing.Drawing2D.DashStyle.DashDotDot
black_pen.Width = 2
Dim point1 As System.Drawing.Point = New System.Drawing.Point(10, 10)
Dim point2 As System.Drawing.Point = New System.Drawing.Point(90, 10)
e.Graphics.DrawLine(black_pen, point1, point2)
End Sub
I am looking for a way to show three different styled lines in my checkbox, which would be selected by the user. My current result is that I can only see one line so far (it's drawn on the top one combobox item) and other combobox items are empty. I see no values there.
How can I add additional lines/drawn graphics into my checkbox and make them "selectable"?
I have 20 checkboxes, with 20 picture boxes above them.
I want to change the back color of those picture boxes whose corresponding checkbox is set to checked = true in form load.
I have used code:
CheckBox1.CheckedChanged
PictureBox1.BackColor = Color.brown
For 20 checkboxes, it will be lengthy process is there any shorter solution so that it changes back color of only those picture boxes whose corresponding checkbox is checked = true in form load
You only want this to be checked in form load that makes it even simpler..
Private Sub Form1_Load(sender As Object, e As EventArgs) Handles MyBase.Load
For i = 1 To 20
Dim cbx As CheckBox = Me.Controls.Find("CheckBox" & i, True).FirstOrDefault
Dim pbx As PictureBox = Me.Controls.Find("PictureBox" & i, True).FirstOrDefault
If cbx.Checked = True Then
pbx.BackColor = Color.Brown
End If
Next
End Sub
Im trying to make a Connect 4 game just to practice some windows forms which im new to. What my code does is creates a grid of 7 x 6 regularly spaces blank PictureBox's. But since im creating them in the script and not using the form1 design windows i dont know how i would add Handles to them, especially since the PictureBox's are in an array. Any ideas?
Public Class Form1
Dim Grid(6, 5) As PictureBox
Private Sub Button1_Click(sender As Object, e As EventArgs) Handles Button1.Click
Button1.Visible = False
Me.FormBorderStyle = FormBorderStyle.FixedSingle
For i As Integer = 0 To 6
For j As Integer = 0 To 5
Grid(i, j) = New PictureBox
Grid(i, j).BackColor = Color.LightGray
Grid(i, j).Size = New Size(90, 90)
Grid(i, j).Location = New Point((i * 100) + 10, (j * 100) + 10)
Grid(i, j).Visible = True
Controls.Add(Grid(i, j))
Next
Next
End Sub
Private Sub Grid_MouseHover(sender As Object, e As EventArgs) Handles Grid(x, y).MouseHover 'Doesnt work
'Run depending on which picturebox in array
End Sub
End Class
I can get an error which is "Handles clause requires a WithEvents variable defined in the containing type or one of its base types."
One possible way would be to set the .Tag property using the coordinates -
add something like into your For..Next loop
Grid(i, j).Tag = i.ToString & j.ToString
and use
AddHandler Grid(i, j).MouseHover, AddressOf Grid_MouseHover
and add this after the one above.
Then, change the first line of your MouseHover Sub to
Private Sub Grid_MouseHover(sender As Object, e As EventArgs)
with no handler on the end.
Finally, change the type of the sender to a PictureBox
Private Sub Grid_MouseHover(sender As Object, e As EventArgs)
Dim Pbox As PictureBox = CType(sender, PictureBox)
Dim i As Integer = Integer.Parse(Pbox.Tag.ToString(0))
Dim j As Integer = Integer.Parse(Pbox.Tag.ToString(1))
End Sub
To access the Picturebox and its properties, just use PBox and if you need the coordinates, use i and j
EDIT:
So now my form location is established as per ZackRyan's answer but I still can't get it to move back to original location after it slides left.
This is the code I expect to move the form to original location
Private Sub Label7_Click(sender As Object, e As EventArgs) Handles Label7.Click
Me.Close()
'Testing.StartPosition.CenterScreen
For MoveLeft = Form2.Location.X To 30 Step 1
Form2.Left = MoveLeft
Form2.Refresh()
Threading.Thread.Sleep(0)
Next
End Sub
This is the original location:
Private Sub Form2_Load(sender As Object, e As EventArgs) Handles MyBase.Load
Dim xLoc = Me.Location.X
Dim yLoc = Me.Location.Y
Me.Location = New Point(xLoc, yLoc)
End Sub
------------------------------------------//--------------------------------------------------
I'm creating a windows app where a form moves to the left smoothly, all ok with this. My problem is bringing it back to it's initial position.
The form is loaded with default position set to CenterScreen I then use the following to move it to the left:
Private Sub Label3_Click(sender As Object, e As EventArgs) Handles Label3.Click
For MoveLeft = FormStartPosition.CenterScreen To 18 Step 1
Me.Left -= MoveLeft
Me.Refresh()
Threading.Thread.Sleep(1)
Next
To make it go back I'm trying the inverse:
Private Sub Label9_Click(sender As Object, e As EventArgs) Handles Label9.Click
For MoveLeft = FormStartPosition.CenterScreen To 18 Step 1
Me.Left = MoveLeft
Me.Refresh()
Threading.Thread.Sleep(1)
Next
This only works partially. The form moves to the right which is what is required, but instead of moving from the current position to CenterScreen, if moves completely at the bottom of the page.
I basically need it to return to its original center screen position smoothly.
Simply store the form's position(on form load) in some variables...
E.g.
Dim xLoc = MyForm.Location.X
Dim yLoc = MyForm.Location.Y
'Or
Dim xLoc = MyForm.Bounds.Left
Dim yLoc = MyForm.Bounds.Top
'or
Dim loc As Point = MyForm.Location
then use it as follows :
MyForm.Location = New Point(xLoc,yLoc)
'or
MyForm.Location = New Point(loc)
And one last thing , i really don't find your code fascinating enough to slide in a form .. You can easily use a Timer for that :
Dim Withevents tmr As New Forms.Timer
Dim myXLocation as integr
Private sub Btn_Click()
Tmr.start()
Private sub tmr_Tick()
myXloc= myXloc+ 1
MyForm.Location=New Point(myXloc,yloc)
If myXloc>= 190 Then 'change 190 to whatever u want :)
Tmr.Stop()
End if
I'm a new programmer to vb.net, so apologise for what is likely to be ignorance.
I’m building a simple gui for a database interface, with many parent and child items within it. Upon a form I create buttons depending on how many items (parents/children). I've got the creation of the buttons thus:
For RowNumber As Integer = 0 To NoOfRows
Dim Buttoni As New Button
Buttoni.Location = New Point(LocationX, LocationY)
Buttoni.Width = 100
Buttoni.Height = 40
Buttoni.Visible = True
Buttoni.Text = DatasetA.Tables(0).Rows(RowNumber).Item("Name")
ButtonName = "Button" + RowNumber.ToString
If LocationX < FormWidth - (SpacePerButtonX * 2) Then
LocationX = LocationX + SpacePerButtonX
Else
LocationX = 50
LocationY = LocationY + SpacePerButtonY
End If
AddHandler Buttoni.Click, AddressOf DynamicButtonClick
Me.Controls.Add(Buttoni)
Buttoni.BringToFront() 'brings newest buttons to front!
Next
But I’m struggling with a way to delete the buttons to make way for a new set to replace them... I can delete a single one upon its click, but I’d like to delete all of the buttons that have been created in this way before re-creating them.
I hope that makes sense and there is a fairly simple way to accomplish this..?
I will add, in your creation loop, some value to the Tag property.
This will help to differentiate the buttons created dinamically from the buttons created statically in your form.
Buttoni.Tag = 1
Then, to delete a button, loop in reverse order on the Me.Controls collection,
check if you get a button and if the Tag property IsNot Nothing
For x as Integer = Me.Controls.Count - 1 to 0 step -1)
Dim b as Button = TryCast(Me.Controls(x), Button)
If b IsNot Nothing AndAlso b.Tag IsNot Nothing then
b.Dispose() '' NOTE: disposing the button also removes it
End If
Next
It's hard to know exactly what you want to do. I guess you could just use the same technique in reverse, something like
For i As Integer = Me.Controls.Count - 1 To 0 Step -1
Dim ctrl = Me.Controls(i)
If TypeOf (ctrl) Is Button Then
ctrl.Dispose() '' NOTE: disposing the control also removes it
End If
Next
Create a button and delete it with double click!
Easy Code :
Dim b As New Button
Private btn As Button ' this is a reference object
Private ptX, ptY As Integer
Private drag As Boolean
Private Sub nodebtn_MouseDown(ByVal sender As Object, ByVal e As System.Windows.Forms.MouseEventArgs)
If e.Clicks = 2 Then
b.Dispose()
End If
If e.Button = MouseButtons.Left Then
drag = True
btn = CType(sender, Button)
ptX = e.X : ptY = e.Y
End If
End Sub
Private Sub nodebtn_MouseMove(ByVal sender As Object, ByVal e As System.Windows.Forms.MouseEventArgs)
If drag Then
btn.Location = New Point(btn.Location.X + e.X - ptX, btn.Location.Y + e.Y - ptY)
Me.Refresh()
End If
End Sub
Private Sub nodebtn_MouseUp(ByVal sender As Object, ByVal e As System.Windows.Forms.MouseEventArgs)
drag = False
End Sub
Private Sub Button1_Click(sender As System.Object, e As System.EventArgs) Handles Button1.Click
b.Location = New Point(10, 10)
b.Size = New Size(110, 29)
b.BringToFront()
b.Text = "Button"
AddHandler b.MouseDown, AddressOf nodebtn_MouseDown
AddHandler b.MouseMove, AddressOf nodebtn_MouseMove
AddHandler b.MouseUp, AddressOf nodebtn_MouseUp
Me.Controls.Add(b)
End Sub