CODEWITHSUNDEEP
androidlistview
Eugene
Eugene

Reputation: 60184

ListView custom background colors

I need to have even rows as white and odd rows sd grey in my ListView (using ArrayAdapter to populate it). I can't use different layouts with different background color because if I do the selection doesn't work. What I do is just use this piece of code in my getView() to check if row is odd or even and apply background depending on condition: 

if (position % 2 == 0) {
convertView.setBackgroundDrawable(getResources().getDrawable(R.drawable.dark_item_background));}

But this doesn't work as expected because the only first visible rows are of correct background color. After scrolling to the bottom (I assume because of recycling mechanism) I have very weird behavior and don't understand why. Here is what I have for the first items (correct case):

enter image description here

Here is what I have after scrolling:

enter image description here

Upvotes: 3

Views: 347

Answers (4)

Lazy Ninja
Lazy Ninja

Reputation: 22527

In getView() objects are reused for better performance.Thats why you get this weird behavior. To solve your problem just add if - else

if (position % 2 == 0) {
   convertView.setBackgroundDrawable(getResources().getDrawable(R.drawable.dark_item_background));
} else {
   convertView.setBackgroundDrawable(getResources().getDrawable(R.drawable.light_item_background));
}

Upvotes: 4

GrIsHu
GrIsHu

Reputation: 23638

I think you need to set the background of the listview rows as below: 

if (position % 2 == 0) {

convertView.setBackgroundDrawable(getResources().getDrawable(R.drawable.dark_item_background));
}
else
{ convertView.setBackgroundDrawable(getResources().getDrawable(R.drawable.light_item_background));
}

Upvotes: 1

Alexandru Cristescu
Alexandru Cristescu

Reputation: 3948

You need to set the ELSE cause as well otherwise all the backgrounds will become black because of the reusing mechanism.

if (position % 2 == 0) {
   convertView.setBackgroundDrawable(getResources().getDrawable(R.drawable.dark_item_background));
} else {
   convertView.setBackgroundDrawable(getResources().getDrawable(R.drawable.light_item_background));
}

Upvotes: 1

Evos
Evos

Reputation: 3915

I think you need to set default color for any reused convert view first, because convert view already can have dark background. So it would be something like this:

convertView.setBackgroundDrawable(getResources().getDrawable(R.drawable.light_item_background));
if (position % 2 == 0) {
    convertView.setBackgroundDrawable(getResources().getDrawable(R.drawable.dark_item_background));
}

Upvotes: 1

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