Accessing multiple PictureBoxes (or any form control) in Visual Basic? - vb.net

So I'm making a game in VB for learning purposes and now I'm struggling with this problem:
I'm trying to do a For loop that draws the level map. However, I just can't seem to figure out it. This is an example of what I'm trying to do:
For index as integer = 1 to 192
PictureBox(index).Image = bg(map(x,y)) 'this is causing me problems
x=x+1
if x=16 then
x=0
y=y+1
End If
Next
But since PictureBox(index).Image doesn't seem to be the correct answer, it simply throws me an error.
Is there any way to do this?
EDIT:
Shortly, I need to set PictureBox.Image's from 1 to 192 like this without having 192 lines of code:
PictureBox1.Image = bg(map(0,0))
PictureBox2.Image = bg(map(1,0))
PictureBox3.Image = bg(map(2,0))
PictureBox4.Image = bg(map(3,0))
'etc....
Instead I wan't to set them in a For loop. I don't want to have extra lines of code.
EDIT2:
The PictureBoxes are added in the editor.

In the designer set the property Tag of each PictureBox to the string value composed by the x and y required to pass to the map function
For example:
PictureBox1 should have the Tag property set to "0,0"
PictureBox2 set the Tag property to "1,0",
....
PictureBox17 will have the Tag property set to "0,1"
and so on until you have mapped all your pictureboxes with the correct values.
Then your code could be changed to
' Assuming the PictureBox are all childs of the Form
For Each pic in Me.Controls.OfType(Of PictureBox)()
Dim tag = pic.Tag
' You could omit this check if you have only the pictureboxes
' set with a valid Tag property
if Not string.IsNullOrEmpty(tag) Then
Dim xyCoords = tag.ToString().Split(","c)
pic.Image = bg(map(Convert.ToInt32(xyCoords(0),
Convert.ToInt32(xyCoords(1))))
End if
Next

I'm going to make a huge assumption here and assume that you already have the PictureBox's on the form prior to reaching this code and they have Id's PictureBox1 through PictureBox192. The code would look like the following. You need to:
1. Retrieve the element by its ID
2. Cast/convert it from an object to a PictureBox
3. Set it's Image property appropriately.
Dim pBox As PictureBox ' To store each pic box in
For index as integer = 1 to 192
pBox = Me.Controls.Find(PictureBox&&index) ' Try to find pic box by ID
If Not pBox Is Nothing Then ' If able to find element by this ID
DirectCast(pBox, PictureBox).Image = bg(map(x,y))
End If
x=x+1
if x=16 then
x=0
y=y+1
End If
Next

Related

Image won't change in picturebox, vb.net

I'm trying to code it so that i can create a picture box from a method in a class. However when my picture box is drawn it doesn't display any image, it only shows a white square of the specified dimensions in the specified location.
Here is the code which i am using to create said picture box:
Public Sub DrawEnemy(ByRef formInstance)
Dim enemypic As New PictureBox
enemypic.Image = Image.FromFile("C:\fboi1\Enemy.Png")
enemypic.Width = 64
enemypic.Height = 64
enemypic.Location = New Point(Me.EnemyPosX, EnemyPosY)
enemypic.Visible = True
formInstance.Controls.Add(enemypic)
End Sub
And here is where i am calling the method from:
Dim Enemy1 As New computerControlled(1, 1)
Enemy1.DrawEnemy(Me)
Please add the following code in your DrawEnemy() method:
enemypic.SizeMode = PictureBoxSizeMode.StretchImage
When i drag the console window suddenly the white box turns into the image i wanted.
Aha! This means the code is not causing the form to be repainted. We can trigger that by calling the Invalidate() function.
Public Sub DrawEnemy(formInstance As Form)
Dim enemypic As New PictureBox
enemypic.Image = Image.FromFile("C:\fboi1\Enemy.Png")
enemypic.Width = 64
enemypic.Height = 64
enemypic.Location = New Point(Me.EnemyPosX, EnemyPosY)
enemypic.Visible = True
formInstance.Controls.Add(enemypic)
formInstance.Invalidate()
End Sub
If you're calling this several times in a loop, you would instead handle this after the loop, where you also block repainting (to prevent flickering) until the loop is finished.
form.SuspendLayout()
For Each enemy In ...
'...
DrawEnemy(form)
Next
form.Invalidate()
form.ResumeLayout()
It's also possible you only need to Invalidate() the picturebox.

For each getting all picture boxes

Building a space invaders game framework and having some issues getting each bullet that's on screen.
The bullet is defined/created using the below :
Dim Bullet As PictureBox
Bullet = New PictureBox()
Controls.Add(Bullet)
For Each Bullet As Control In Me.Controls
If TypeOf Bullet Is PictureBox Then
If Bullet.Visible = True Then
BulletTimer.Enabled = True
Bullet.Top = Bullet.Top - 10
End If
End If
Next
The problem I've got is that this gets every picture box on screen, including the player and enemies and sends the whole lot flying upwards rather than just the bullets.
You can use the Tag property present in every control. Set the Tag property of the PictureBox to something that identify your PictureBox as a bullet. For example you can set it to the string "BULLET".
Then your loop checks if the PictureBox has the Tag set and if the Tag property has the value "BULLET"
Dim Bullet As PictureBox
Bullet = New PictureBox()
Bullet.Tag = "BULLET"
Controls.Add(Bullet)
....
For Each Bullet As PictureBox In Me.Controls.OfType(Of PictureBox)
If Bullet.Tag IsNot Nothing AndAlso Bullet.Tag.ToString = "BULLET" Then
If Bullet.Visible = True Then
BulletTimer.Enabled = True
Bullet.Top = Bullet.Top - 10
End If
End If
Next
Notice that you can simplify your loop using the OfType(T) extension to retrieve only PictureBox from the controls collection. This remove the need to check if the control is a PictureBox.

Change Font Style on All Instances of a String in a RichTextBox

I'm working on a VB.NET 4.5 project in VS2013.
I have a richtextbox on a form and when a button is clicked I need to toggle the BOLD setting on all instances of a specific string found in the richtextbox.
I put together some code based on this question.
Private Sub ToggleBold()
rtxtOutputText.SelectionStart = rtxtOutputText.Find("##$%", RichTextBoxFinds.None)
rtxtOutputText.SelectionFont = New Font(rtxtOutputText.Font, FontStyle.Bold)
End Sub
However when the toggle bold button is clicked it only bolds the first instance of the string "##$%".
How can I set all instances of the string to bold? There can also be several of them strung together ("##$%##$%##$%"), so each of those would need to be bolded too.
(I know I mentioned toggling bold, but I'll set up the toggle portion later, right now I'm just trying to get the bold on all instances working right...)
Just add a loop to it and use the RichTextBox.Find(String, Int32, RichTextBoxFinds) overload to specify from where to start looking. Look from the current index + 1 so that it doesn't return the same again.
You also ought to actually select the word as well, so that you're sure the bold applies to the current instance only and not the text around it.
Private Sub ToggleBold()
'Stop the control from redrawing itself while we process it.
rtxtOutputText.SuspendLayout()
Dim LookFor As String = "##$%"
Dim PreviousPosition As Integer = rtxtOutputText.SelectionStart
Dim PreviousSelection As Integer = rtxtOutputText.SelectionLength
Dim SelectionIndex As Integer = -1
Using BoldFont As New Font(rtxtOutputText.Font, FontStyle.Bold)
While True
SelectionIndex = rtxtOutputText.Find(LookFor, SelectionIndex + 1, RichTextBoxFinds.None)
If SelectionIndex < 0 Then Exit While 'No more matches found.
rtxtOutputText.SelectionStart = SelectionIndex
rtxtOutputText.SelectionLength = LookFor.Length
rtxtOutputText.SelectionFont = BoldFont
End While
End Using
'Allow the control to redraw itself again.
rtxtOutputText.ResumeLayout()
'Restore the previous selection.
rtxtOutputText.SelectionStart = PreviousPosition
rtxtOutputText.SelectionLength = PreviousSelection
End Sub
Credit to Plutonix for telling me to dispose the font.

WP use string as name of control

Please, can anyone help me with this problem:
I have a name(s) of control(s) in string format (str) and I want to set property (in code) of that controls using that string-name.
I try something like this but it doesn't work. Actually, I have a problem with expression. When I put exactly the name it works but when i use variable in string format it doesn't.
Dim str as String
str="k3"
Dim g As Image = CType(str, Image)
g.Source = New BitmapImage(New Uri("/APP;component/Icons/hero.png", UriKind.Relative))
This works:
Dim g As Image = CType(k3, Image)
While this does not:
Dim g As Image = CType(str, Image)
I think I understand what you are trying to do, to declare an object by a string...
Essentially for this to work you will need a custom function that returns the Object Type that you are seeking...
You will need to loop through each control and check the name of the control as a comparison, e.g. If oControl.Name.ToString = sString then Return oControl
Example
' A function to return a Control by the Control's name...
Public Function GetControlByName(ByVal oForm As Form, ByVal sName As String) As Control
Dim cReturn As New Control
Dim ctrl As Control
For Each ctrl In oForm.Controls
cReturn = ctrl
If ctrl.Name.ToString = sName Then
Return ctrl ' this is what we want!
End If
Next
Return cReturn
End Function
' Example Usage
Dim oButton As Button = GetControlByName(Me, "Button44")
If oButton.Name.ToString = "Button44" Then
MessageBox.Show("I have found your Button!")
Else
MessageBox.Show("Your button was NOT Found!")
End If
Obviously there is room for error with this function, because if sName is NOT found, then it will return the last ctrl found, therefore, you will need to ensure that the control you seek is indeed found, via the If statement as provided in the example above...
Furthermore, it may not loop through controls inside of containers, menus, etc, but I'm not sure on that, so you will need to check to ensure it's not having that problem...
(The Me in the statement will most likely be used more often than not, though Me could be the name of the form you are searching if you are running the code outside of the form you are searching the form with the function.)
FINALLY, to answer your question, you will need to change Control to Image, and Set CReturn as a New Image, and then use Return ctrl.BackgroundImage (etc) to return the image..

Looping through Controls in VB.NET

I am creating a chess program. And it is composed of sixty four picture boxes with alternating black and white background colours.
I have named them pba1, pba2, pbb1, pbb2, pbc1 and so on.
Now, I want to loop through only the black ones, for example, I want to loop through only, pba1, pbb2, pbc3 and so on.
How do I create a loop for this in VB.NET?
I know of the way to loop through similarly named controls, but I am not able to adapt that method for my problem. Can you tell me a solution?
EDIT: In pba1, pb stands for picture box, and a1 stands for the square. Just in case, you wonder why such a name.
EDIT: Check out this answer
Loop through the PictureBox's in your ControlCollection and test for BackColor. I used the Form's ControlCollection, if they are in some other type of container control use that.
For Each cntrl As Control In Me.Controls
If TypeOf cntrl Is PictureBox Then
If cntrl.BackColor = Color.Black Then
'Do Something
End If
End If
Next
Base on the additional information that you gave in your answer, the reason your example is not working is that the Controls Name is a String and you are comparing it to the PictureBox Control not the Name of the Control.
You can try using the Tag Property instead of the Name of the Control, it will be cleaner and easier to read. I just put a 1 in the PictureBox's Tag Property for Black and a 0 for White.
Private Sub OriginalColour()
For Each cntrl As Control In Me.Controls
Dim result As Integer
If TypeOf cntrl Is PictureBox Then
If Integer.TryParse(cntrl.Tag.ToString, result) Then
If result = 1 Then
cntrl.BackColor = Color.Gray
Else
cntrl.BackColor = Color.White
End If
End If
End If
Next
End Sub
Generating controls at design time via the Forms Designer only makes sense for layouts which benefit from the forms designer.
In your case, you just have 64 uniform boxes in 8 rows of 8. Don’t use the Forms Designer for this, create the controls at runtime, and don’t give them names like pba1, just put them into an appropriate data structure (such as an 8x8 array):
Private chessFields As PictureBox(8, 8)
' In Form_Load:
For i = 0 To 7
For j = 0 To 7
chessFields(i, j) = New PictureBox
' Set size, position … then, finally,
Controls.Add(chessFields(i, j))
Next
Next
That way, you can access the fields in an orderly fashion without having to go via the Form.Controls collection.
Put all the pictureboxes in an 8x8 tableLayoutPanel (also useful for scaling etc). Then
For Each pb As PictureBox In TableLayoutPanel1.Controls
Dim col As Integer = TableLayoutPanel1.GetCellPosition(pb).Column
Dim row As Integer = TableLayoutPanel1.GetCellPosition(pb).Row
If col Mod 2 = 0 Xor row Mod 2 = 0 Then
pb.BackColor = Color.Black
Else
pb.BackColor = Color.White
End If
Next
Of course you could also use an array of the squares if you have that available.
This will not affect the events (pba1.click etc).
This is fairly simple and it may be resource heavy, but it works. I have a form with 36 CheckBoxes. This takes advantage of the fact that when you copy a checkbox it just increases the number of the name. I ended up with 36 checkboxes named CheckBox1 thru Checkbox36. The Function returns a checkbox, which may be used to set or read any property.
Private Function GetCheckBox(ByVal Index As Integer) As CheckBox
Dim CKBox As checkbox
For Each cntrl As Control In Me.Controls
If TypeOf cntrl Is CheckBox Then
CKBox = cntrl
If CKBox.Name = "CheckBox" & Index Then
Exit For
End If
End If
Next
Return ckbox
End Function