android - Unresolved 对 Kotlin Android 中函数的引用

Question

我的 MainActivity 中有以下 onCreate 函数。

override fun onCreate(savedInstanceState: Bundle?) {
    super.onCreate(savedInstanceState)
    setContentView(R.layout.activity_main)

    var selected_answer = 0

    val btn_list = mutableListOf<ToggleButton>(button1, button2, button3, button4)

    for(i in btn_list){
        i.setOnClickListener{
            toggle_rest(btn_list.indexOf(i), btn_list)
            selected_answer = btn_list.indexOf(i)+1

        }
    }


    fun toggle_rest(toCheck : Int, btn_list : List<ToggleButton>){


        for (i in btn_list) {
            i.setChecked(btn_list.indexOf(i) == toCheck)

        }
    }
    question_txt.setText("Quiz will begin shortly!")
}

当我调用 toggle_rest 时出现错误 toggle_rest:Unresolved reference。

Answer 1

在你的代码中使用之前你必须定义toggle_rest函数，否则你会得到unresolve reference编译错误:

override fun onCreate(savedInstanceState: Bundle?) {
    super.onCreate(savedInstanceState)
    setContentView(R.layout.activity_main)

    var selected_answer = 0

    //Declare your function before you use
    fun toggle_rest(toCheck : Int, btn_list : List<ToggleButton>){
        for (i in btn_list) {
            i.setChecked(btn_list.indexOf(i) == toCheck)
        }
    }

    val btn_list = mutableListOf<ToggleButton>(button1, button2, button3, button4)

    for(i in btn_list){
        i.setOnClickListener{
            toggle_rest(btn_list.indexOf(i), btn_list)
            selected_answer = btn_list.indexOf(i)+1
        }
    }

    question_txt.setText("Quiz will begin shortly!")
}