Firebase 修饰符'；覆盖'；不适用于'；局部函数'；

在android中使用firebase realtime datqabase时，我遇到以下错误

 val catListener =  object : ValueEventListener {
        override fun onDataChange(dataSnapshot: DataSnapshot) {
            if (dataSnapshot.exists()) {
                // Get Post object and use the values to update the UI
                for (eventSnapshot in dataSnapshot.children) {
                    val name = eventSnapshot.child("name").getValue() as String
                    list.add(Category(name));
                }

                var adp = CategoryAdapter(list);
                cat_rv.adapter = adp

                adp.onItemClick = { pos, view ->

                    i.putExtra("category", list[pos].name)
                    startActivity(i)
                }
            }

            override fun onCancelled(databaseError: DatabaseError) {
                // Getting Post failed, log a message
                Log.w("Category", "loadCat:onCancelled", databaseError.toException())

            }
        }

错误--

修饰符“覆盖”不适用于“本地函数”（指对象：ValueListener

对象不是抽象的，并且不实现抽象成员public 抽象fun onCancelled（@NonNull p0:DatabaseError）：中定义的单位 com.google.firebase.database.ValueEventListener

---

您缺少所有类型的语法-主要是右大括号。这是使您获得有效Kotlin语法的最低限度

    val catListener =  object : ValueEventListener {
        override fun onDataChange(dataSnapshot: DataSnapshot) {
            if (dataSnapshot.exists()) {
                // Get Post object and use the values to update the UI
                for (eventSnapshot in dataSnapshot.children) {
                }
            }
        }

        override fun onCancelled(databaseError: DatabaseError) {
            // Getting Post failed, log a message
            Log.w("Category", "loadCat:onCancelled", databaseError.toException())

        }

---

您缺少所有类型的语法-主要是右大括号。这是使您获得有效Kotlin语法的最低限度

    val catListener =  object : ValueEventListener {
        override fun onDataChange(dataSnapshot: DataSnapshot) {
            if (dataSnapshot.exists()) {
                // Get Post object and use the values to update the UI
                for (eventSnapshot in dataSnapshot.children) {
                }
            }
        }

        override fun onCancelled(databaseError: DatabaseError) {
            // Getting Post failed, log a message
            Log.w("Category", "loadCat:onCancelled", databaseError.toException())

        }

更改此项：

 val catListener =  object : ValueEventListener {
        override fun onDataChange(dataSnapshot: DataSnapshot) {
            if (dataSnapshot.exists()) {
                // Get Post object and use the values to update the UI
                for (eventSnapshot in dataSnapshot.children) {
                    val name = eventSnapshot.child("name").getValue() as String
                    list.add(Category(name));
                }

                var adp = CategoryAdapter(list);
                cat_rv.adapter = adp

                adp.onItemClick = { pos, view ->

                    i.putExtra("category", list[pos].name)
                    startActivity(i)
                }
            }

            override fun onCancelled(databaseError: DatabaseError) {
                // Getting Post failed, log a message
                Log.w("Category", "loadCat:onCancelled", databaseError.toException())

            }
        }

为此：

 val catListener =  object : ValueEventListener {
        override fun onDataChange(dataSnapshot: DataSnapshot) {
            if (dataSnapshot.exists()) {
                // Get Post object and use the values to update the UI
                for (eventSnapshot in dataSnapshot.children) {
                    val name = eventSnapshot.child("name").getValue() as String
                    list.add(Category(name));
                }

                var adp = CategoryAdapter(list);
                cat_rv.adapter = adp

                adp.onItemClick = { pos, view ->

                    i.putExtra("category", list[pos].name)
                    startActivity(i)
                }
              }
           }

            override fun onCancelled(databaseError: DatabaseError) {
                // Getting Post failed, log a message
                Log.w("Category", "loadCat:onCancelled", databaseError.toException())

            }
        }

您缺少一个括号，请更改以下内容：

 val catListener =  object : ValueEventListener {
        override fun onDataChange(dataSnapshot: DataSnapshot) {
            if (dataSnapshot.exists()) {
                // Get Post object and use the values to update the UI
                for (eventSnapshot in dataSnapshot.children) {
                    val name = eventSnapshot.child("name").getValue() as String
                    list.add(Category(name));
                }

                var adp = CategoryAdapter(list);
                cat_rv.adapter = adp

                adp.onItemClick = { pos, view ->

                    i.putExtra("category", list[pos].name)
                    startActivity(i)
                }
            }

            override fun onCancelled(databaseError: DatabaseError) {
                // Getting Post failed, log a message
                Log.w("Category", "loadCat:onCancelled", databaseError.toException())

            }
        }

为此：

 val catListener =  object : ValueEventListener {
        override fun onDataChange(dataSnapshot: DataSnapshot) {
            if (dataSnapshot.exists()) {
                // Get Post object and use the values to update the UI
                for (eventSnapshot in dataSnapshot.children) {
                    val name = eventSnapshot.child("name").getValue() as String
                    list.add(Category(name));
                }

                var adp = CategoryAdapter(list);
                cat_rv.adapter = adp

                adp.onItemClick = { pos, view ->

                    i.putExtra("category", list[pos].name)
                    startActivity(i)
                }
              }
           }

            override fun onCancelled(databaseError: DatabaseError) {
                // Getting Post failed, log a message
                Log.w("Category", "loadCat:onCancelled", databaseError.toException())

            }
        }

---

你缺少一个括号

是的，很抱歉我给出了部分代码。上面的代码给了我一个错误。我编辑了我的问题。仍然得到相同的错误。你仍然有语法错误。这里没有足够的信息来了解你要表达的意思。请尝试自己解决语法问题-堆栈溢出不是问题一个非常好的编译器错误迭代论坛。是的，很抱歉我给出了部分代码。上面的代码给了我一个错误。我编辑了我的问题。仍然得到相同的错误。您仍然有语法错误。这里没有足够的信息来了解您要表达的意思。请尝试在您自己的堆栈中解决语法问题对于编译器错误的迭代，Overflow不是一个很好的论坛。