View must have a tag error in android data binding

Question

I\'ve two layouts for a screen. Activity works fine while setting a layout for Mobile device but it\'s causing error while setting layout for tablet device. The main issue is:

Answer 1

I was having this problem when using an array adapter, having a crash due to a missing tag on convertView. In my getView(), I was doing:

override fun getView(position: Int, convertView: View?, parent: ViewGroup): View {
    if (convertView == null) {
        DataBindingUtil.inflate<ItemSpinnerDropDownWorkPackageFilterBinding>(
            LayoutInflater.from(parent.context),
            R.layout.item_spinner_drop_down_work_package_filter,
            parent,
            false
        )
    } else {
        binding = ItemSpinnerDropDownWorkPackageFilterBinding.bind(convertView) 
        binding.text1.setText(getItem(position))
        setDividerVisibility(binding.divider, position)
        return convertView
    }    

}

Which was crashing. The solution was to set the tag on the first run through getView:

 override fun getView(position: Int, convertView: View?, parent: ViewGroup): View {
    val binding = if (convertView == null) {
        DataBindingUtil.inflate<ItemSpinnerDropDownWorkPackageFilterBinding>(
            LayoutInflater.from(parent.context),
            R.layout.item_spinner_drop_down_work_package_filter,
            parent,
            false
        )
    } else {
        convertView.tag as ItemSpinnerDropDownWorkPackageFilterBinding
    }
    binding.text1.setText(getItem(position))
    setDividerVisibility(binding.divider, position)
    binding.root.tag = binding
    return binding.root

}

Answer 2

You need to add layout tag at start of your app_toolbar_layout layout file

Answer 3

You must have <layout> tag into your all XML views (portrait, landscape, tablet, etc.). Even you have to include <layout> tag into included views ("@layout/app_toolbar_layout").

Answer 4

I just needed to clean and rebuild after deleting a resource file.

Answer 5

Keeping two layouts, one with layout tag of data-binding and another without it, is the common cause of this issue.

I got stuck when I renamed my two normal layout files with same name (/layout and /layout-sw720dp) and used tag. Then, it worked for mobile device but not for tablet. So, after cleaning project, it all started working.

Answer 6

I ran into this when I had:

• A library module defining a layout resource
• An app module that depended upon that library module defining the same layout resource
• The library layout resource was set up for data binding (e.g., root <layout> element), but the app module's edition of that layout resource was not

In my case, the app module's layout was left over from when I created the project. Removing it cleared up the problem.