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.
Related
I am running into an issue where I am attempting to add some blank rows to a datagridview before printing the form for use.
I am having an issue trying to understand where I need to put the code to add the rows to the data gridview so they are added and captured before the user hits print. My concern is that I am not adding the rows in the right spot before the screen is captured however the code to add the rows is run before the code to hide the buttons is implemented however the buttons are removed and the rows are not added in the actual printed image.
If that is not clear hopefully these images will make more sense. At this point I am not sure why the buttons being hidden are being captured but the added rows are not when based on the code it looks like the rows are being added before the buttons are hidden.
Thank you.
Here is the Image before the user hits print
Here is the Image after the user hits Print
And here is what actually printed
And here is the code in question that captures the screen
Private Sub CaptureScreen()
Dim myGraphics As Graphics = Me.CreateGraphics()
Dim s As Size = Me.Size
If dgvReceive.Rows.Count < 27 Then
Dim rowstoadd As Integer = 0
rowstoadd = 27 - dgvReceive.Rows.Count
dgvReceive.Rows.Add(rowstoadd)
End If
If MemoryImage IsNot Nothing Then
MemoryImage.Dispose()
End If
MemoryImage = New Bitmap(s.Width, s.Height, myGraphics)
For Each btn As Button In Me.Controls.OfType(Of Button)
btn.Visible = False
Next
dgvReceive.ClearSelection()
lblTitle.Select()
Me.FormBorderStyle = FormBorderStyle.None
Dim memoryGraphics As Graphics = Graphics.FromImage(MemoryImage)
memoryGraphics.CopyFromScreen(Me.Location.X, Me.Location.Y, 0, 0, s)
Me.FormBorderStyle = FormBorderStyle.Sizable
For Each btn As Button In Me.Controls.OfType(Of Button)
btn.Visible = True
Next
End Sub
I have many labels. When a label is clicked, I change the BackColor to aqua. When I click on another label, both of them are aqua, but I want the color of the first label to go back to normal. It there a way to do that?
Here is my code:
Dim clickedLabel = TryCast(sender, Label)
If clickedLabel IsNot Nothing Then
clickedLabel.BackColor = Color.Aqua
TextBox1.Text = clickedLabel.Text
Else
End If
Put them all in a collection so that you can apply the default-color on all others or - if they are all in the same container-control like a Panel - use this code:
For Each lbl In LabelPanel.Controls.OfType(Of Label)()
clickedLabel.BackColor = If(lbl Is clickedLabel, Color.Aqua, DefaultColor)
Next
TextBox1.Text = clickedLabel.Text
Instead of LabelPanel.Controls you could also use Me.Controls, but then all labels on the form are used even if it's not related. Labels that are in other container controls won't be find in this way anyway, so no recursive search.
DefaultColor is a System.Drawing.Color that you store as class/member variable(shared or as instance-variable).
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
I imagine this is probably an easy to answer question but for some reason I can't get it to work
Sub New(ByVal Sess As AudioSessionControl2)
S_Session = Sess
'Create the panel and position it.
S_Panel.BackColor = Color.AliceBlue
S_Panel.Width = 200
S_Panel.Height = 40
Dim Position As New Point(6, 19)
If G_AppSessions.Count > 0 Then
Position = Point.Add(G_AppSessions.Item(G_AppSessions.Count - 1).SessionPanel.Location, New Point(0, 45))
End If
S_Panel.Location = Position
'Create a label which has the name of the process
Dim S_PName As New Label
S_PName.Text = "Test"
S_PName.Dock = DockStyle.Left
S_Panel.Controls.Add(S_PName)
'Create a button to change volume
Dim S_Save As New Button()
S_Save.Text = "Save"
AddHandler S_Save.Click, AddressOf Save_Click
S_Save.Parent = S_Panel
S_Panel.Controls.Add(S_Save)
S_Volume.Parent = S_Panel
S_PName.Parent = S_Panel
MainForm.Controls.Add(S_Panel)
S_Panel.Parent = MainForm.gb_Applications
End Sub
The problem is that, the label will show because its docked, but the button won't. It will only show if its docked as well, and thats just not what I want. This is part of a class for creating a dynamic UI, where I can create a number of this class to create a bunch of panels for various things.
I don't see anywhere where you are setting the label or button position. You probably have them both at 0,0 and the label is on top of the button, obscuring it. Did you try setting the position of both the controls, making sure they don't overlap?
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