How to pass data using bundle in fragment-CodePudding

Whenever I'm trying to pass data from one fragment to other, In next fragment it's returning null

CodePudding user response：

let's transfer data from Fragment A to Fragment B with a Bundle.

class FragmentB : Fragment() {
      companion object {
     const val KEY_DATA = "KEY_DATA"
        fun newInstance(data: String?) = FragmentB().apply{
            arguments = Bundle().apply {
                putString(KEY_DATA, data)
            }
        }
    }

Now let's send data from FragmentA to FragmentB.

getNavController().pushFragment(FragmentB.newInstance(data))

I gave string as an example, but you can send any value, you can also send data class.

So, how can we get the data in FragmentB?

val sampleData = arguments?.getString(KEY_DATA)

CodePudding user response：

class MyFragment: Fragment {

  ...

companion object {

        @JvmStatic
        fun newInstance(isMyBoolean: Boolean) 
        = MyFragment().apply {
            arguments = Bundle().apply {
                putBoolean("REPLACE WITH A STRING CONSTANT"
                ,isMyBoolean)
            }
        }
      }
   }

Here is the Android Studio proposed solution (= when you create a Blank-Fragment with File -> New -> Fragment -> Fragment(Blank) and you check "include fragment factory methods").

Put this in your Fragment:

companion object {

        @JvmStatic
        fun newInstance(isMyBoolean: Boolean) 
        =  MyFragment().apply {
            arguments = Bundle().apply {
                putBoolean("REPLACE WITH A STRING CONSTANT"
                , isMyBoolean)
            }
         }
        }
       }

.apply is a nice trick to set data when an object is created, or as they state here:

Calls the specified function [block] with this value as its receiver and returns this value.

Then in your Activity or Fragment do:

val fragment = MyFragment.newInstance(false)
... // transaction stuff happening here

and read the Arguments in your Fragment such as:

 private var isMyBoolean = false
 override fun onAttach(context: Context?) {
 super.onAttach(context)
 arguments?.getBoolean("REPLACE WITH A STRING CONSTANT")?
 .let {
    isMyBoolean = it
  }
}

for more info this should help.