看不见的无限循环

Question

我的代码中有一个无限循环。在我完全关闭程序之前，它一直在向我的 Firebase 数据库写入数据......我真的需要帮助，请帮忙。我希望我的函数 MemberAdding 在单击按钮后仅执行一次...

override fun MemberAdding(accountKey: String) {
    DBdatabaseName!!.reference!!.child(user!!.currentUser!!.uid).child("Group-List").addValueEventListener(object : ValueEventListener{
        override fun onDataChange(dataSnapshot: DataSnapshot) {
            groupKey = intent.getStringExtra("GroupKey")
            val flag = dataSnapshot.child("Groups").child(groupKey).child("members").value.toString()
            val newpath = "member" + flag

            DBdatabaseName!!.reference!!.child(user!!.currentUser!!.uid).child("Group-List").child("Groups").child(groupKey).child(newpath).setValue(accountKey)

        }


        override fun onCancelled(databaseError: DatabaseError) {

        }
    })

    DBdatabaseName!!.reference!!.child(user!!.currentUser!!.uid).child("Group-List").addValueEventListener(object : ValueEventListener{
        override fun onDataChange(dataSnapshot: DataSnapshot) {
            val groupKey = intent.getStringExtra("GroupKey")
            var flag = dataSnapshot.child("Groups").child(groupKey).child("members").value.toString()
            val flag2 = flag.toInt()
            val flag3 = flag2 + 1


            DBdatabaseName!!.reference!!.child(user!!.currentUser!!.uid).child("Group-List").child("Groups").child(groupKey).child("members").setValue(flag3)

        }


        override fun onCancelled(databaseError: DatabaseError) {

        }
    })



    refresh()

}

private fun refresh() {
    groupKey = intent.getStringExtra("GroupKey")
    val intent = Intent(this@GroupMemberAddingActivity, GroupMemberAddingActivity::class.java)
    intent.putExtra("GroupKey", groupKey)
    startActivity(intent)
}

}

在下面，我还将发送我正在使用的适配器 class

class GroupMemberAddingItemAdapter (context: Context, friendItemList: MutableList<FriendItem>) : BaseAdapter() {
private class  ListRowHolder (row: View? ) {
    val label: TextView = row!!.findViewById(R.id.friendName_textview) as TextView
    val addMember: Button? = row!!.findViewById(R.id.addMember_button) as Button

}

private val mInflater: LayoutInflater = LayoutInflater.from(context)
private var itemList = friendItemList
private var mView: View? = null
private var rowListener: GroupMemberAddingRowListener = context as GroupMemberAddingRowListener

override fun getView(position: Int, convertView: View?, parent: ViewGroup?): View {

    val friendName: String = itemList.get(position).friendName as String
    val friendLastName: String = itemList.get(position).friendLastName as String
    val friendemail: String = itemList.get(position).accountKey as String

    val vh: ListRowHolder
    if (convertView == null) {
        mView = mInflater.inflate(R.layout.groupmemberadding_row, parent, false)

        vh = ListRowHolder(mView)
        mView!!.tag = vh
    } else {
        mView = convertView
        vh = mView!!.tag as ListRowHolder
    }

    vh.label.text = "$friendName $friendLastName"
    vh.addMember!!.setOnClickListener{rowListener.MemberAdding(friendemail)}

    return mView!!

}

override fun getItem(index: Int): Any {
    return itemList[index]
}

override fun getItemId(index: Int): Long {
    return index.toLong()
}

override fun getCount(): Int {
    return itemList.size
}
}

我的初始行监听器是......

interface GroupMemberAddingRowListener {
    fun MemberAdding (accountKey:String)
}

如果您需要更多代码部分，请告诉我....感谢您的帮助

Answer 1

首先，你必须调试并查看它发生的位置，无论如何我认为它在 onDataChanged 实现中自从你开火：

 DBdatabaseName!!.reference!!.child(user!!.currentUser!!.uid).child("Group-List").child("Groups").child(groupKey).child("members").setValue(flag3)

setValue 会再次触发 onDataChanged。

Answer 2

我找到问题了

DBdatabaseName!!.reference!!.child(user!!.currentUser!!.uid).child("Group-List").addValueEventListener(object : ValueEventListener{
    override fun onDataChange(dataSnapshot: DataSnapshot) {

Line make onDataChange 每次数据更改时都会回调...（罪魁祸首是 addValueEventListener）所以我将其更改为

BdatabaseName!!.reference!!.child(user!!.currentUser!!.uid).child("Group-List").addListenerForSingleValueEvent(object : ValueEventListener{
        override fun onDataChange(dataSnapshot: DataSnapshot) {

addListenerForSingleValueEvent 仅调用一次 onDataChange，然后销毁所有回调

看不见的无限循环

Invisible infinite loop

android

infinite-loop

kotlin