Moving an image

[EdTheGreat]

How would i make an image move across the screen so that when you hold down a certain button it moves in that direction.

Also if i take an image from a webpic how would I take out the background of that webpic, so It will match the background of the form, or the pic thats behind it...

Sorry im teaching myself how to program

[kedaman]

Not too hard to move the image with keys:

Private Sub Form_KeyDown(KeyCode As Integer, Shift As Integer)
With Image1
Select Case KeyCode
Case vbKeyUp
.Top = .Top - 100
Case vbKeyDown
.Top = .Top + 100
Case vbKeyLeft
.Left = .Left - 100
Case vbKeyRight
.Left = .Left + 100
End Select
End With
End Sub

if you have several controls on the form, set keypreview to true and it will always fire the forms keydown event even if the controls have focus

If you want support for multipule key presses then use GtAsyncKeyState API instead.

Add the following code to a Form with a Timer and a PictureBox.

Private Declare Function GetAsyncKeyState Lib "user32" (ByVal vKey As Long) As Integer

Private Sub Form_Load()
Timer1.Interval = 1
End Sub

Private Sub Timer1_Timer()
If GetAsyncKeyState(vbKeyLeft) Then Picture1.Left = Picture1.Left - 100
If GetAsyncKeyState(vbKeyRight) Then Picture1.Left = Picture1.Left + 100
If GetAsyncKeyState(vbKeyUp) Then Picture1.Top = Picture1.Top - 100
If GetAsyncKeyState(vbKeyDown) Then Picture1.Top = Picture1.Top + 100
End Sub

[kedaman]

Meg, the timer method won't execute more frequently than once in 53ms and Getasynckeystate could miss some of the keys, on the other hand you will catch all the keydown events.

[Mad Compie]

Meg and Keda, what's the thing about GetAsyncKeyState(). I'm looking forward to implement some code to create a software keyboard (for my touchscreen monitor).
I tried to use GetAsyncKeyState(), but I frequently receive strange chars, while opening i.e. Notepad, typing some text, and returning to my app.
Is there any given time table for this API, because chars are repeated while holding down a key...?

[kedaman]

Compie, have an array of all keys (I know i've done this with DirectInput) Then in the method you call frequently, compare all values in the array, this is a bit slow (maybe you could xor them with some apis) and then if an item has changed, then the button has been released or been pressed,check the original array.

[Mad Compie]

Yes, this is the code I had in mind.
I found it in the API guide on http://www.allapi.net.

TimerProc() does the equality comparison.

But when I run the code and goto the start menu, run, "notepad" and typing some chars then returning to VB,
some strange prefix chars are being displayed.


'In a module
Public Const DT_CENTER = &H1
Public Const DT_WORDBREAK = &H10
Type RECT
Left As Long
Top As Long
Right As Long
Bottom As Long
End Type
Declare Function DrawTextEx Lib "user32" Alias "DrawTextExA" (ByVal hDC As Long, ByVal lpsz As String, ByVal n As Long, lpRect As RECT, ByVal un As Long, ByVal lpDrawTextParams As Any) As Long
Declare Function SetTimer Lib "user32" (ByVal hwnd As Long, ByVal nIDEvent As Long, ByVal uElapse As Long, ByVal lpTimerFunc As Long) As Long
Declare Function KillTimer Lib "user32" (ByVal hwnd As Long, ByVal nIDEvent As Long) As Long
Declare Function GetAsyncKeyState Lib "user32" (ByVal vKey As Long) As Integer
Declare Function SetRect Lib "user32" (lpRect As RECT, ByVal X1 As Long, ByVal Y1 As Long, ByVal X2 As Long, ByVal Y2 As Long) As Long
Global Cnt As Long, sSave As String, sOld As String, Ret As String
Dim Tel As Long
Function GetPressedKey() As String
For Cnt = 32 To 128
'Get the keystate of a specified key
If GetAsyncKeyState(Cnt) <> 0 Then
GetPressedKey = Chr$(Cnt)
Exit For
End If
Next Cnt
End Function
Sub TimerProc(ByVal hwnd As Long, ByVal nIDEvent As Long, ByVal uElapse As Long, ByVal lpTimerFunc As Long)
Ret = GetPressedKey
If Ret <> sOld Then
sOld = Ret
sSave = sSave + sOld
End If
End Sub

'In a form
Private Sub Form_Load()
'KPD-Team 1999
'URL: http://www.allapi.net/
'E-Mail: KPDTeam@Allapi.net
Me.Caption = "Key Spy"
'Create an API-timer
SetTimer Me.hwnd, 0, 1, AddressOf TimerProc
End Sub
Private Sub Form_Paint()
Dim R As RECT
Const mStr = "Start this project, go to another application, type something, switch back to this application and unload the form. If you unload the form, a messagebox with all the typed keys will be shown."
'Clear the form
Me.Cls
'API uses pixels
Me.ScaleMode = vbPixels
'Set the rectangle's values
SetRect R, 0, 0, Me.ScaleWidth, Me.ScaleHeight
'Draw the text on the form
DrawTextEx Me.hDC, mStr, Len(mStr), R, DT_WORDBREAK Or DT_CENTER, ByVal 0&
End Sub
Private Sub Form_Resize()
Form_Paint
End Sub
Private Sub Form_Unload(Cancel As Integer)
'Kill our API-timer
KillTimer Me.hwnd, 0
'Show all the typed keys
MsgBox sSave
End Sub