你如何找到没有点击的单选按钮？

Question

我有一个无线电组用于设置数据类的属性，特别是三明治。 到目前为止，我的方法是这样的：如果选中了三明治，我手动设置三明治可见，如果没有选择三明治，则手动设置三明治不可见。 我想通过使用一个函数来简化它，但我不确定如何找到未选择的单选按钮 ID。 我是 Kotlin 和 Android 的新手，所以任何帮助将不胜感激。

fun onSandwichRadioButtonClicked(view: View) {
        if (view is RadioButton) {
            // Is the button now checked?
            val checked = view.isChecked

            // Check which radio button was clicked
            when (view.getId()) {
                R.id.panini_button ->
                    if (checked) {
                        sandwich.sandwichCost = 7.0f
                        sandwich.name = "Panini"
                        binding.panini.visibility = View.VISIBLE
                        binding.hoagie.visibility = View.GONE
                        binding.sandwich.visibility = View.GONE
                    }
                R.id.hoagie_button ->
                    if (checked) {
                        sandwich.sandwichCost = 10.0f
                        sandwich.name = "Hoagie"
                        binding.panini.visibility = View.GONE
                        binding.hoagie.visibility = View.VISIBLE
                        binding.sandwich.visibility = View.GONE
                    }
                R.id.sandwich_button ->
                    if (checked) {
                        sandwich.sandwichCost = 5.0f
                        sandwich.name = "Sandwich"
                        binding.panini.visibility = View.GONE
                        binding.hoagie.visibility = View.GONE
                        binding.sandwich.visibility = View.VISIBLE
                    }
            }
            sandwich.totalCost = (sandwich.extraCost + sandwich.sandwichCost).toString()
            binding.invalidateAll()
            Toast.makeText(
                activity, "Total Cost :" +
                        " ${sandwich.totalCost}",
                Toast.LENGTH_SHORT
            ).show()
        }
    }

    fun setSandwich(sandwichName: String, sandwichCost: Float, sandwichImage: ImageView){
        sandwich.sandwichCost = sandwichCost
        sandwich.name = sandwichName
        sandwichImage.visibility = View.VISIBLE
        //set the remaining sandwiches to invisible. how do I find these sandwiches?

相关的xml代码：

 <ImageView
            android:id="@+id/panini"
            android:layout_width="192dp"
            android:layout_height="79dp"
            android:contentDescription="TODO"
            app:layout_constraintBottom_toBottomOf="parent"
            app:layout_constraintEnd_toEndOf="parent"
            app:layout_constraintHorizontal_bias="0.497"
            app:layout_constraintStart_toStartOf="parent"
            app:layout_constraintTop_toTopOf="parent"
            app:layout_constraintVertical_bias="0.411"
            app:srcCompat="@drawable/ic_food_obvious_panini"
            tools:visibility="visible" />

        <ImageView
            android:id="@+id/hoagie"
            android:layout_width="149dp"
            android:layout_height="153dp"
            app:layout_constraintBottom_toBottomOf="parent"
            app:layout_constraintEnd_toEndOf="parent"
            app:layout_constraintHorizontal_bias="0.503"
            app:layout_constraintStart_toStartOf="parent"
            app:layout_constraintTop_toTopOf="parent"
            app:layout_constraintVertical_bias="0.394"
            app:srcCompat="@drawable/hoagie"
            tools:visibility="gone" />

        <ImageView
            android:id="@+id/sandwich"
            android:layout_width="140dp"
            android:layout_height="311dp"
            app:layout_constraintBottom_toBottomOf="parent"
            app:layout_constraintEnd_toEndOf="parent"
            app:layout_constraintHorizontal_bias="0.498"
            app:layout_constraintStart_toStartOf="parent"
            app:layout_constraintTop_toTopOf="parent"
            app:layout_constraintVertical_bias="0.345"
            app:srcCompat="@drawable/ic_sandwhichanddrink"
            tools:visibility="visible" />


        <RadioGroup
            android:id="@+id/sandwichRadioGroup"
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:orientation="horizontal"
            app:layout_constraintBottom_toTopOf="@+id/tomatoes_check"
            app:layout_constraintEnd_toEndOf="parent"
            app:layout_constraintStart_toStartOf="parent"
            app:layout_constraintTop_toTopOf="parent"
            app:layout_constraintVertical_bias="0.88">

            <RadioButton
                android:id="@+id/sandwich_button"
                android:layout_width="wrap_content"
                android:layout_height="wrap_content"
                android:onClick="onSandwichRadioButtonClicked"
                android:text="@string/sandwich"
                android:textSize="24sp" />

            <RadioButton
                android:id="@+id/hoagie_button"
                android:layout_width="wrap_content"
                android:layout_height="wrap_content"
                android:onClick="onSandwichRadioButtonClicked"
                android:text="@string/hoagie"
                android:textSize="24sp" />

            <RadioButton
                android:id="@+id/panini_button"
                android:layout_width="wrap_content"
                android:layout_height="wrap_content"
                android:onClick="onSandwichRadioButtonClicked"
                android:text="@string/panini"
                android:textSize="24sp" />
        </RadioGroup>

更新：我已经简化了一点，但我觉得它仍然可以更好。 图像视图的 ArrayList 是我当前的解决方法：

fun onSandwichRadioButtonClicked(view: View) {

        var notChosenSandwiches: ArrayList<ImageView> = ArrayList()
        if (view is RadioButton) {
            // Is the button now checked?
            val checked = view.isChecked

            // Check which radio button was clicked
            when (view.getId()) {
                R.id.panini_button ->
                    if (checked) {
                        notChosenSandwiches.clear()
                        notChosenSandwiches.add(binding.hoagie)
                        notChosenSandwiches.add(binding.sandwich)
                        setSandwich("Panini", 7.0f, binding.panini, notChosenSandwiches)
                    }
                R.id.hoagie_button ->
                    if (checked) {
                        notChosenSandwiches.clear()
                        notChosenSandwiches.add(binding.panini)
                        notChosenSandwiches.add(binding.sandwich)
                        setSandwich("Hoagie", 10.0f, binding.hoagie, notChosenSandwiches)
                    }
                R.id.sandwich_button ->
                    if (checked) {
                        notChosenSandwiches.clear()
                        notChosenSandwiches.add(binding.hoagie)
                        notChosenSandwiches.add(binding.panini)
                        setSandwich("Melt", 5.0f, binding.sandwich, notChosenSandwiches)
                    }
            }
            sandwich.totalCost = (sandwich.extraCost + sandwich.sandwichCost).toString()
            binding.invalidateAll()
            Toast.makeText(
                activity, "Total Cost :" +
                        " ${sandwich.totalCost}",
                Toast.LENGTH_SHORT
            ).show()
        }
    }

    /**
     * update the sandwich and the views
     *
     * @param sandwichName the new name of the sandwich
     * @param sandwichCost the new cost of the sandwich
     * @param shownImage the image of the sandwich
     * @param hideThese the not chosen sandwiches
*/
    fun setSandwich(sandwichName: String, sandwichCost: Float, shownImage: ImageView, hideThese: ArrayList<ImageView>){
        sandwich.sandwichCost = sandwichCost
        sandwich.name = sandwichName
        shownImage.visibility = View.VISIBLE
        for (image in hideThese)
            image.visibility = View.GONE
    }

Answer 1

您的问题是您知道所选按钮的 ID，并且想要列出所有其他（未选择的）ID，以便您可以对它们做一些有用的事情吗？

看起来RadioGroup不会为您提供其按钮列表（只是当前选择了哪个），因此您可能必须自己生成。 它是LinearLayout的一个子类，所以它没有做任何复杂的事情，它只是将所有RadioButton作为直接子级，所以你可以这样做：

sandwichButtons = sandwichRadioGroup.children
    .filterIsInstance(RadioButton::class.java).toList()

这给你一个List<RadioButton> 。 或者，如果您只想要他们的 ID：

    sandwichButtonIds = sandwichRadioGroup.children
    .filterIsInstance(RadioButton::class.java)
    .map { it.id }
    .toList()

这是一个List<Int>及其所有 ID（ R.id.hoagie值）。 如果您将其设置为lateinit var字段，并在onCreate或onViewCreated或其他期间使用查找进行分配，您将拥有一个包含组中所有单选按钮的不错列表。 然后你可以做这样的事情：

val unselected = sandwichButtonIds.minus(selectedId)

可能有很多事情可以帮助您完成工作，但我现在只能猜测，所以希望这是一个开始！ “数据类，特别是三明治”也得到了我的支持