用VB可以在屏幕上绘图吗?

[oksonic]

就象手写板中的功能一样,可以直接在屏幕上写字..

[ShaLongBus]

可以啊，只要取得DeskTop的HWND和HDC就可以了

[DemonLoveLizzy]

GETDC(0),然后画就可以了。取的的不是DESKTOP，而是除了已激活窗体外的背景DC。

[SafeF8]

'This Project needs
'- two timers, interval=100
'- a button

'in general section
Private Type POINTAPI
x As Long
y As Long
End Type

Private Declare Function GetActiveWindow Lib "user32" () As Long
Private Declare Function GetWindowDC Lib "user32" (ByVal hwnd As Long) As Long
Private Declare Function Ellipse Lib "gdi32" (ByVal hdc As Long, ByVal X1 As Long, ByVal Y1 As Long, ByVal X2 As Long, ByVal Y2 As Long) As Long

Private Declare Function TextOut Lib "gdi32" Alias "TextOutA" (ByVal hdc As Long, ByVal x As Long, ByVal y As Long, ByVal lpString As String, ByVal nCount As Long) As Long
Private Declare Function GetCursorPos Lib "user32" (lpPoint As POINTAPI) As Long
Private Sub Form_Load()
Timer1.Interval = 100
Timer1.Enabled = True
Timer2.Interval = 100
Timer2.Enabled = True
Command1.Caption = "Draw Text"
End Sub
'This will draw an Ellipse on the active window
Sub Timer1_Timer()
Dim Position As POINTAPI
'Get the cursor position
GetCursorPos Position
'Draw the Ellipse on the Screen's DC
Ellipse GetWindowDC(0), Position.x - 5, Position.y - 5, Position.x + 5, Position.y + 5
End Sub
Sub Command1_Click()
'KPD-Team 1998
'URL: http://www.allapi.net/
'E-Mail: [e-mail]

Dim intCount As Integer, strString As String
strString = "Cool, text on screen !"
For intCount = 0 To 30
'Draw the text on the screen
TextOut GetWindowDC(0), intCount * 20, intCount * 20, strString, Len(strString)
Next intCount
End Sub
Private Sub Timer2_Timer()
'Draw the text to the active window
TextOut GetWindowDC(GetActiveWindow), 50, 50, "This is a form", 14
End Sub

[chenghua]

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