Android Question Lack of Memory (multiple bitmaps and images)

[Scott Heywood]

Hello,

I'm putting together a simple flashcard app where I'm loading multiple bitmaps and images and receiving the lack of memory error as the app crashes. From what I can gather from the forums there seems to be a consensus that using multiple bitmaps and images often yields this result. In the app I have a different activity for each topic. As I move through the activities I think loaded bitmaps from previous activities remain stored in the memory, so it doesn't take long for the app to crash. I'm not sure how to solve this problem or if that is even the issue.

I've posted the code from one the activities to illustrate how I've set up my code. I'm sure there is a more eloquent and efficient way to write the below code that will solve the lack of memory problem, so I welcome any tips and suggestions.

Sub Globals
    Private svp As StdViewPager   
   
    Private BearImage As ImageView
    Private BirdImage As ImageView
    Private CatImage As ImageView
    Private ChickenImage As ImageView
    Private CowImage As ImageView
    Private DogImage As ImageView
    Private ElephantImage As ImageView
    Private FishImage As ImageView
    Private HorseImage As ImageView
    Private LionImage As ImageView
    Private MonkeyImage As ImageView
    Private SheepImage As ImageView
    Private PigImage As ImageView
End Sub

Sub Activity_Create(FirstTime As Boolean)
    svp.Initialize("svp",13,100%x,100%y)
    Activity.AddView(svp.AsView,0,0,100%x,100%y)
   
    svp.Panels(0).LoadLayout("Bear.bal")
    svp.Panels(1).LoadLayout("Bird.bal")
    svp.Panels(2).LoadLayout("Cat.bal")
    svp.Panels(3).LoadLayout("Chicken.bal")
    svp.Panels(4).LoadLayout("Cow.bal")
    svp.Panels(5).LoadLayout("Dog.bal")
    svp.Panels(6).LoadLayout("Elephant.bal")
    svp.Panels(7).LoadLayout("Fish.bal")
    svp.Panels(8).LoadLayout("Horse.bal")
    svp.Panels(9).LoadLayout("Lion.bal")
    svp.Panels(10).LoadLayout("Monkey.bal")
    svp.Panels(11).LoadLayout("Sheep.bal")
    svp.Panels(12).LoadLayout("Pig.bal")
       
    Dim bmp1 As Bitmap = ResizeImage(LoadBitmapSample(File.DirAssets, "Bear.jpg",Activity.Width,Activity.Height), 100%x, 100%y)
      Dim bmp2 As Bitmap = ResizeImage(LoadBitmapSample(File.DirAssets, "Bird.jpg",Activity.Width,activity.Height), 100%x, 100%y)
    Dim bmp3 As Bitmap = ResizeImage(LoadBitmapSample(File.DirAssets, "Cat.jpg",Activity.Width,activity.Height), 100%x, 100%y)
    Dim bmp4 As Bitmap = ResizeImage(LoadBitmapSample(File.DirAssets, "Chicken.jpg",Activity.Width,activity.Height), 100%x, 100%y)
    Dim bmp5 As Bitmap = ResizeImage(LoadBitmapSample(File.DirAssets, "Cow.jpg",Activity.Width,activity.Height), 100%x, 100%y)
    Dim bmp6 As Bitmap = ResizeImage(LoadBitmapSample(File.DirAssets, "Dog.jpg",Activity.Width,activity.Height), 100%x, 100%y)
    Dim bmp7 As Bitmap = ResizeImage(LoadBitmapSample(File.DirAssets, "Elephant.jpg",Activity.Width,activity.Height), 100%x, 100%y)
    Dim bmp8 As Bitmap = ResizeImage(LoadBitmapSample(File.DirAssets, "Fish.jpg",Activity.Width,activity.Height), 100%x, 100%y)
    Dim bmp9 As Bitmap = ResizeImage(LoadBitmapSample(File.DirAssets, "Horse.jpg",Activity.Width,activity.Height), 100%x, 100%y)
    Dim bmp10 As Bitmap = ResizeImage(LoadBitmapSample(File.DirAssets, "Lion.jpg",Activity.Width,activity.Height), 100%x, 100%y)
    Dim bmp11 As Bitmap = ResizeImage(LoadBitmapSample(File.DirAssets, "Monkey.jpg",Activity.Width,activity.Height), 100%x, 100%y)
    Dim bmp12 As Bitmap = ResizeImage(LoadBitmapSample(File.DirAssets, "Sheep.jpg",Activity.Width,activity.Height), 100%x, 100%y)
    Dim bmp13 As Bitmap = ResizeImage(LoadBitmapSample(File.DirAssets, "Pig.jpg",Activity.Width,activity.Height), 100%x, 100%y)
   
   
    BearImage.Bitmap = bmp1
    BirdImage.Bitmap = bmp2
    CatImage.Bitmap = bmp3
    ChickenImage.Bitmap = bmp4
    CowImage.Bitmap = bmp5
    DogImage.Bitmap = bmp6
    ElephantImage.Bitmap = bmp7
    FishImage.Bitmap = bmp8
    HorseImage.Bitmap = bmp9
    LionImage.Bitmap = bmp10
    MonkeyImage.Bitmap = bmp11
    SheepImage.Bitmap = bmp12
    PigImage.Bitmap = bmp13
   
End Sub
Sub ResizeImage(original As Bitmap, TargetX As Int, TargetY As Int) As Bitmap
   Dim origRatio As Float = original.Width / original.Height
   Dim targetRatio As Float = TargetX / TargetY
   Dim scale As Float
  
   If targetRatio > origRatio Then
      scale = TargetY / original.Height
   Else
      scale = TargetX / original.Width
   End If
  
   Dim c As Canvas
   Dim b As Bitmap
   b.InitializeMutable(TargetX, TargetY)
   c.Initialize2(b)
   'set the background
   c.DrawColor(Colors.LightGray)
   Dim r As Rect
   Dim w = original.Width * scale, h = original.Height * scale As Int
   r.Initialize(TargetX / 2 - w / 2, TargetY / 2 - h / 2, TargetX / 2 + w / 2, TargetY / 2+ h / 2)
   c.DrawBitmap(original, Null, r)
   Return b
End Sub

 

[sorex]

why don't you load the image only when it gets show?

 

[Scott Heywood]

why don't you load the image only when it gets show?

Thank you for your reply sorex. I think that would definitely solve the issue, although I'm not sure how to approach it. What would be the best way to load the images only when they are shown and does that conflict with the StdViewPager? Could you possibly provide a short example?

 

[sorex]

Well, I don't know exactly what you are trying to do but you seem to have multiple panels with bitmaps.

more ideal would be 1 panel with 1 bitmap where you load the required/requested image in based on the selection.

that might reduce memory by 12/13th already if the images all are the same size.

 

[Scott Heywood]

I ended up reducing the images size to prevent the lack of memory error. This seems to be working for now, but if I run into the same problem down the road I'll have to explore using 1 panel with 1 bitmap as you suggested.

Thanks,