Android Question Populating an Endless Preoptimized CLV With Images and Text

[Mahares]

I have an endless Preoptimized CLV that works ok except for populating imageview1. The only way I got it to populate was to put this line:

ImageView1.Bitmap=LoadBitmapResize(File.DirAssets,ad.flagname,ImageView1.Width, ImageView1.Height, True)

in the: Sub clv_VisibleRangeChanged (FirstIndex As Int, LastIndex As Int) which means I am loading the bitmap file every record, not the proper way. Is there away to avoid loading the file for each image every scroll. I am having trouble with: ad.img. My relevant code in question is below:
Thank you

 Type AllData(img As Bitmap, flagname As String)  'in Globals

Sub Activity_Create(FirstTime As Boolean)
    Activity.LoadLayout("Main")  'has clv only
    PCLV.Initialize(Me, "PCLV", clv)
    l.Initialize
    MyList.Initialize
    l = File.ListFiles(File.DirAssets)
    For i=0 To l.Size -1
        Dim MyFile As String = l.Get(i)
        If MyFile.EndsWith(".png")  Then MyList.Add(MyFile)
    Next
    MyList.Sort(True)   
    NumberOfRealItems = MyList.Size
    For i = 0 To 1000
        Dim ad As AllData
        ad.flagname= MyList.Get(i Mod NumberOfRealItems)
        PCLV.AddItem(150dip, Rnd(0xff000000, -1),ad) 
    Next
    PCLV.Commit
    Sleep(0)
    clv.JumpToItem(500 - (500 Mod NumberOfRealItems))
End Sub

Sub clv_VisibleRangeChanged (FirstIndex As Int, LastIndex As Int)
    For Each i As Int In PCLV.VisibleRangeChanged(FirstIndex, LastIndex)
        Dim item As CLVItem = clv.GetRawListItem(i)
        Dim pnl As B4XView = xui.CreatePanel("")
'        item.Panel.AddView(pnl, 0, 0, item.Panel.Width, 100dip)
        item.Panel.AddView(pnl, 0, 0, item.Panel.Width-50dip, item.Panel.Height)
        'Create the item layout
        pnl.LoadLayout("cellitem")    'has imageview1 and Label1
        Dim ad As AllData
        ad=item.Value
       
        Label1.Text = ad.flagname
        Label1.TextColor = xui.Color_Yellow
        Label1.SetColorAndBorder(xui.Color_Red, 5dip, xui.Color_Yellow, 10dip)
'        ImageView1.Bitmap = Null       
        ImageView1.Bitmap=LoadBitmapResize(File.DirAssets,ad.flagname,ImageView1.Width, ImageView1.Height, True)
'        ImageView1.Bitmap= ad.img   
    Next
End Sub

EDIT 040920: I changed part of my code to this and it seems to work, but not sure if is the best approach

For i = 0 To 1000
        Dim ad As AllData
        ad.flagname= MyList.Get(i Mod NumberOfRealItems)
        ad.img = LoadBitmapResize(File.DirAssets, ad.flagname, 100dip, 75dip, True)
        PCLV.AddItem(150dip, Rnd(0xff000000, -1),ad)  '85dip vertical
    Next

I also commented the not needed line: ImageView1.Bitmap=.............. in Sub clv_VisibleRangeChanged (F

 

[Erel]

What is the total number of images?

 

[Mahares]

I am still experimenting with the total number now to make it work, but we are probably talking about 350 to 400 images for now. I just like to avoid having to reload images every time if I can. I can limit the number of images to whatever an endless PCLV can comfortably handle.

 

[Erel]

to whatever an endless PCLV can comfortably handle

No such thing.

The correct thing to do with many images is to load them when needed and discard them when not needed. Exactly like done in your current code.