Android Question CustomListview Gradient background colors at runtime ?

[Addo]

can i set the customlistview background color to gradient colors at run time ?

i cannot find any property to do that

 

[Erel]

Are you asking about the full list background or the background of each item?

Both can be changed at runtime.

Dim sv As ScrollView = CLV.sv
'create a GradientDrawable and set it to sv.Background

 

[Addo]

Thank you very much

 

[Addo]

i have did like following

Dim sv As ScrollView = clv.sv
Dim gd(2) As Int
gd(0) = Colors.RGB(0, 95, 170)
gd(1) = Colors.RGB(0, 190, 255)
Dim gdContent As GradientDrawable
gdContent.Initialize("LEFT_RIGHT", gd)

sv.Background = gdContent

the clv background changed but the items inside the clv have a diffrent color any idea why ?

 

[Addo]

should i loop through clv items and set each item panel background as gradient as well or there is more simple way ?

 

[mangojack]

should i loop through clv items and set each item panel background as gradient as well or there is more simple way ?

You could do that ... Or

In your CLV Item layout place views on a Panel and set the background tp GradientDrawable ... Or

Color the Item Panel when loading items to the CLV.

Sub CreateListItem(Text As String, Width As Int, Height As Int) As Panel
    Dim p As Panel
    p.Initialize("")
    'set panel color gradient  ... Not tested.!

 

[Addo]

I think its better to use a timer in my case sense I will change the clv colors each 1 minute.

Also timer could be a good choice sense each time I put the application to background or open the keyboard the clv gradient background cleared and had to be re drawed.

 

[Addo]

@mangojack i have also tried to do the same method you have posted

like following

Sub CreateListItem(Text As String, Width As Int, Height As Int) As Panel
Dim itempnl As Panel

itempnl.Initialize("")
itempnl.LoadLayout("itemlayout")


Dim gd(2) As Int
gd(0) = Colors.White
gd(1) = Colors.Blue
Dim gdContent As GradientDrawable
gdContent.Initialize("LEFT_RIGHT", gd)
itempnl.Background = gdContent


Return itempnl
  
  
End Sub

i got this exception when ever i try to set background

java.lang.NullPointerException: Attempt to invoke virtual method 'int android.content.res.ColorStateList.getDefaultColor()' on a null object reference

what iam doing wrong ?

 

[Erel]

1. Never call LoadLayout on a zero sized panel.

Dim itempnl As B4XView = XUI.CreatePanel("")
itempnl.SetLayoutAnimated(0, 0, 0, Width, Height)

2. xCLV expects the root panel color to be a solid color. Add another panel in the layout that is anchored to BOTH sides and then change its background.