I have a Fragment_A on Activity_1 and whenever a Button is clicked in the Fragment_A I have to start Activity_2 witch have a Fragment_B

So i need to send a user_Id from the Fragment_A in Activity 1 to the Fragment_B in activity_2. Is there any way to send the data directly from Frament_A in Activity_1 to Fragment_B in Activity_2?

I am a student , so i am a beginner and i did found this question here but i didn't understand what to do to solve this I did find some solution about interface but i didn't know how to do it

i keep getting class_id null

Language : Kotlin

Class : ClassesAdapter

class ClassesAdapter(val c:Fragment,val l:android.content.Context? ,val classeslist: ArrayList<Classes>) : RecyclerView.Adapter <ClassesAdapter.ClassesViewHolder> (){
    lateinit var auth: FirebaseAuth
    lateinit var DataBase : DatabaseReference
    lateinit var DataBase2 : DatabaseReference
    lateinit var clipboardManager: ClipboardManager


    private lateinit var mListener :onItemClickListener

    interface onItemClickListener {

        fun onItemClick(position :Int)

    }

    /*fun setOnItemClickListener(listener : onItemClickListener){

       // mListener=listener

    }*/

    override fun onCreateViewHolder(parent: ViewGroup, viewType: Int): ClassesViewHolder {
        val itemView = LayoutInflater.from(parent.context).inflate(R.layout.class_items2,parent,false)
        //return ClassesViewHolder(itemView,mListener)
        return ClassesViewHolder(itemView,)
    }


  
    
        override fun onBindViewHolder(holder: ClassesViewHolder, position: Int) {
            val currentitem = classeslist[position]
            holder.classname.text = currentitem.name
            holder.classrole.text = currentitem.role
    
            holder.itemView.setOnClickListener {
    
    
                val intent = Intent(l, DetailedClassActivity::class.java)
                intent.putExtra("classId", currentitem.class_id)
                l!!.startActivity(intent)
    
            }

Class : Acttivity2 who has the fragment iwant to send it the class_id`

val intent=getIntent()
        var classId= intent.getStringExtra("classId")
        val bundle=Bundle()
        bundle.putString("classId",classId)
        val fragment=DocumentsFragment()
        fragment.setArguments(bundle)
   

class : fragment B

enter code here
 btnAddcourse.setOnClickListener {
            var nameofthecourse = Coursename.text.toString().trim()
            var course_id :String?=DataBase3.push().key
            
            var classId = arguments?.getString("classId")
           
            
            val dateofthecourse: String = formatTimeStamp()

            if (TextUtils.isEmpty(nameofthecourse)) {
                // No name added
                Coursename.error = "No name added !! Please enter the name of the class"
            }
            else{
                courseList.add(Course(course_id,nameofthecourse,dateofthecourse,classId))
                coursesAdapter.notifyDataSetChanged()
                Toast.makeText(activity,"Adding Course Success", Toast.LENGTH_SHORT).show()
                //Toast.makeText(activity,"class_id is null ", Toast.LENGTH_SHORT).show()
                if (classId != null) {
                    addCourseToDataBase(course_id!!,nameofthecourse,dateofthecourse,classId)
                }else{
                    Toast.makeText(activity,"class_id is null ", Toast.LENGTH_SHORT).show()
                }
            }
        }

CodePudding user response：

fragmentA

button.setOnClickListener { 
    val intent = Intent(requireContext(), Activity2::class.java)
                intent.putExtra("user_Id", user_Id)
                startActivity(intent)
 }

activity2

val intent = getIntent()
val message = intent.getStringExtra("user_Id")

val bundle = Bundle()
bundle.putString("user_Id", message) //the part i updated
val fragmet= fragment_B()   
fragmet.setArguments(bundle)

fragmentB

override fun onCreateView(
    inflater: LayoutInflater, container: ViewGroup?,
    savedInstanceState: Bundle?
): View? {
    return inflater.inflate(R.layout.fragment_B, container, false)
    val bundle = this.arguments //the part i updated
    val myString = bundle!!.getString("user_Id", "defaultValue") //the part i updated
}

CodePudding user response：

1-Read About Singleton Design Pattern for make user id global in all app

1. read it to understand

2-Shared Preference :save user id to can using for all app

1. Shared Preferences

3-you can try Navigation Args : better choose for performance and can use it for movement through you app

1. Navigation