Android Question dotted crop

Sub Process_Globals
    'These global variables will be declared once when the application starts.
    'These variables can be accessed from all modules.

End Sub

Sub Globals
    'These global variables will be redeclared each time the activity is created.
    'These variables can only be accessed from this module.
    Dim iv As ImageView
    Dim c As Canvas
    Dim btn As Button
End Sub

Sub Activity_Create(FirstTime As Boolean)
    'Do not forget to load the layout file created with the visual designer. For example:
    'Activity.LoadLayout("Layout1")
    iv.Initialize("iv")
    btn.Initialize("btn")
    Activity.AddView(iv,0,0,100%x,100%y)
    Activity.AddView(btn,40%x,90%y,20%x,10%y)
    btn.Text="Draw"
End Sub

Sub Activity_Resume

End Sub

Sub Activity_Pause (UserClosed As Boolean)

End Sub

Sub btn_click
   
    drawdotline(10%x,10%y,80%x,80%y)
End Sub

Sub drawdotline(x1,y1,x2,y2 As Int)
    Dim lx,ly As Int
    Dim rect1 As Rect
    c.Initialize(iv)
    rect1.Initialize(0,0,100%x,100%y)
    c.DrawRect(rect1,Colors.Transparent,True,1)
    lx=x1
    ly=y1
    Do While lx<(x2-1%x)
        c.DrawLine(lx,y1,lx+1%x,y1,Colors.Blue,1)
        c.DrawLine(lx,y2,lx+1%x,y2,Colors.Blue,1)
        lx=lx+2%x
    Loop
    Do While ly<(y2-1%y)
        c.DrawLine(x1,ly,x1,ly+1%y,Colors.Blue,1)
        c.DrawLine(x2,ly,x2,ly+1%y,Colors.Blue,1)
        ly=ly+2%y
    Loop
End Sub