如何在PreferenceScreen中显示单选按钮列表（不在对话框中）

Question

如何在PreferenceSecreen中而不是对话框中显示单选按钮列表？多次单击仅从此列表中选择一个项目真的很烦。

预期结果

当前结果

app_preferences.xml

<?xml version="1.0" encoding="utf-8"?>
<PreferenceScreen xmlns:android="http://schemas.android.com/apk/res/android">

    <ListPreference
            android:key="prefPhotoFilter"
            android:title="Photo filter"
            android:entries="@array/photoFilters" />

</PreferenceScreen>

strings.xml中

<string-array name="photoFilters">
    <item name="1">Natural</item>
    <item name="2">Boosted</item>
    <item name="3">Saturated</item>
</string-array>

Answer 1

根据此Gist，您可以扩展CheckBoxPreference并使用单选按钮创建布局。

像这样：首先，创建一个仅包含单选按钮的新布局，让我们称之为[]

preference_widget_radiobutton.xml

<?xml version="1.0" encoding="utf-8"?>
<RadioButton xmlns:android="http://schemas.android.com/apk/res/android"
        android:id="@android:id/checkbox"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_gravity="center"
        android:clickable="false"
        android:focusable="false" />
然后创建CheckBoxPreference的子类：

class RadioButtonPreference : CheckBoxPreference {

    constructor(context: Context, attrs: AttributeSet, defStyle: Int) : super(context, attrs, defStyle) { setView() }

    constructor(context: Context, attrs: AttributeSet? = null) : super(context, attrs) { setView() }


    private fun setView(){
        widgetLayoutResource = R.layout.preference_widget_radiobutton
    }

    override fun onClick() {
        if (this.isChecked) 
            return

        super.onClick()
    }
}
在app_preferences.xml屏幕中：

    <PreferenceCategory android:title="Photo Filters">
        <Your_class_package_dirctory.RadioButtonPreference
                android:key="naturals"
                android:title="Natural" />
        <Your_class_package_dirctory.RadioButtonPreference
                android:key="boosted"
                android:title="Boosted" />
        <Your_class_package_dirctory.RadioButtonPreference
                android:key="saturated"
                android:title="Saturated" />
    </PreferenceCategory>
现在，您将看到它的行为类似于普通的CheckBox，它将不会取消选中以前的单选按钮来解决此问题：

在您的首选项屏幕代码中：

class SettingsFragment : PreferenceFragmentCompat(), Preference.OnPreferenceClickListener{
    private val sharedPreference = AppPreferences()


    private var oldCheckedPreference: RadioButtonPreference? = null

    override fun onCreatePreferences(savedInstanceState: Bundle?, rootKey: String?) {
        setPreferencesFromResource(R.xml.app_preferences, rootKey)

        findPreference<RadioButtonPreference>("naturals")?.apply {
            /*
            You can set the defualt button to be checked by:
              updateCheckedRadioButton(this)
            */
            onPreferenceClickListener = this@SettingsFragment
        }
        findPreference<RadioButtonPreference>("boosted")?.onPreferenceClickListener = this
        findPreference<RadioButtonPreference>("saturated")?.onPreferenceClickListener = this

    }

    private fun updateCheckedRadioButton(radioButtonPreference: RadioButtonPreference) {

        //Uncheck the previous selected button if there is.
        oldCheckedPreference?.isChecked = false
        radioButtonPreference.isChecked = true
        oldCheckedPreference = radioButtonPreference

    }

    override fun onPreferenceClick(preference: Preference): Boolean {
        if (preference is RadioButtonPreference)
            updateCheckedRadioButton(preference)

        return true
    }

}

结果是：