Android Question CreateBitmapWithAlpha with android 8.1 (SOLVED)

[BeneBarros]

My Samsung J7 Neo phone updated the android to 8.1.
Now the "CreateBitmapWithAlpha" routine does not work right. It's locking.
Can someone help me?

Private Sub CreateBitmapWithAlpha(myOriginalBitmap As Bitmap, newAlpha As Int) As Bitmap
  Dim canvas1 As Canvas
  Dim myNewBitmap As Bitmap
  myNewBitmap.initializeMutable(myOriginalBitmap.Width,myOriginalBitmap.Height)
  canvas1.initialize2(myNewBitmap)
  Dim CanvJO As JavaObject = canvas1
  CanvJO = CanvJO.GetField("canvas") 
  Dim J As JavaObject
  J.initializeContext()
  J.Runmethod("alphatize",Array(CanvJO, myOriginalBitmap, newAlpha))
  Return(myNewBitmap)
End Sub

 

[JordiCP]

What do the logs say?

 

[BeneBarros]

What do the logs say?

does not generate errors, only takes approximately 5 seconds for each execution

 

[Peter Simpson]

Have you tried in debug mode to single step through each line of code until the code hangs for a while, you can see exactly where it hangs then?

Are you sure that it's hanging in the CreateBitmapWithAlpha sub?

You could also try using

Try
   
Catch
    Log(LastException)
End Try

 

[BeneBarros]

does not generate errors, only takes approximately 5 seconds for each execution

If you have android 8.1 installed, try this little example on it and then on any other version

 

[JordiCP]

Tested. If you add some measurements to your code you will find that the time is not lost in "CreateBitmapWithalpha", but on "DrawFirework"
Modify your TimeR_Tick routine

Private Sub Timer_Tick
    Dim t0 As Long = DateTime.now    '<--- Added
    For fIdx = 0  To nFires - 1
        DrawFireWork(fIdx) 
    Next
    Dim t1 As Long =DateTime.now
    Dim bmp As Bitmap = CreateBitmapWithAlpha(ivFireW.Bitmap, 245) 

    Dim tFinal As Long = DateTime.now     '<--- Added   
    Log("DrawFirework took "&(t1-t0)&"msec.  CreateBitmapWithAlpha took:"&(tFinal -t1)&"msec")   '<--- Added

    ivFireW.Bitmap = bmp
    gv.Invalidate
End Sub

When the fires start, the logs say

...
DrawFirework took 0msec.  CreateBitmapWithAlpha took:6msec
DrawFirework took 0msec.  CreateBitmapWithAlpha took:6msec
DrawFirework took 0msec.  CreateBitmapWithAlpha took:6msec
...

But after some time, perhaps when the fireworks do Booommmmm!!!!!, these are the logs

...
DrawFirework took 33msec.  CreateBitmapWithAlpha took:5msec
DrawFirework took 288msec.  CreateBitmapWithAlpha took:6msec
DrawFirework took 281msec.  CreateBitmapWithAlpha took:5msec
DrawFirework took 567msec.  CreateBitmapWithAlpha took:7msec
DrawFirework took 571msec.  CreateBitmapWithAlpha took:5msec
DrawFirework took 599msec.  CreateBitmapWithAlpha took:6msec
... 
...(and increasing)

 

[BeneBarros]

Ok, I got it. Thanks for the tip.

I just do not understand why in the other versions it works perfectly.

 

[BeneBarros]

Very strange.
The problem is happening in Canvas.DrawBitmap

If lines 107 and 117 have been replaced

from
cvs.DrawBitmap (imgSparks, RtSrc, RtDest)

to
cvs.DrawCircle (nFW.X, nFW.Y, 1, Colors.White, True, 0)


it works perfectly

 

[Erel]

I haven't tried your project. Make sure that imgSparks is not too large. The smaller it will be the faster the drawing will be.

 

[BeneBarros]

I haven't tried your project. Make sure that imgSparks is not too large. The smaller it will be the faster the drawing will be.

hi Erel,
Image sparks is small, 300x300px.
Application runs on all versions of android, except on 8.1.
The problem only happens in Canvas.DrawBitmap ().
If I change to Canvas.DrawCircle () it works perfectly.

 

[BeneBarros]

hi Erel,
Image sparks is small, 300x300px.
Application runs on all versions of android, except on 8.1.
The problem only happens in Canvas.DrawBitmap ().
If I change to Canvas.DrawCircle () it works perfectly.

Ok, Erel, you're right. decreasing the image size improves performance.

Is this a problem with version 8.1?

 

[Erel]

I don't think that it is a general issue with Android 8.1.