android-如何在Kotlin的设置活动首选项中使用侦听器

如何解决android-如何在Kotlin的设置活动首选项中使用侦听器

我没有java / kotlin / android背景，已经尝试了一周。我停留在设置活动监听器

我使用新建>活动>设置活动创建了设置活动，并添加了SeekBar

但是无论我如何尝试，我都无法使println("triggered")零件正常工作

我在做什么错？请不要忘记我是新手，而

谢谢

PS：API级别为21

SettingsActivity.kt

import android.os.Bundle
import android.text.InputType
import android.view.inputmethod.EditorInfo
import android.widget.EditText
import android.widget.SeekBar
import androidx.appcompat.app.AppCompatActivity
import androidx.preference.EditTextPreference
import androidx.preference.PreferenceFragmentCompat


class SettingsActivity2 : AppCompatActivity(),SeekBar.OnSeekBarchangelistener,EditTextPreference.OnBindEditTextListener {

    override fun onCreate(savedInstanceState: Bundle?) {
        super.onCreate(savedInstanceState)
        setContentView(R.layout.settings_activity)
        if (savedInstanceState == null) {
            supportFragmentManager
                .beginTransaction()
                .replace(R.id.settings,SettingsFragment())
                .commit()
        }
        supportActionBar?.setdisplayHomeAsUpEnabled(true)
    }

    class SettingsFragment : PreferenceFragmentCompat() {
        override fun onCreatePreferences(savedInstanceState: Bundle?,rootKey: String?) {
            setPreferencesFromresource(R.xml.root_preferences,rootKey)
        }
    }

    override fun onProgressChanged(seekBar: SeekBar?,progress: Int,fromUser: Boolean) {
        println("triggered1")
    }

    override fun onStartTrackingTouch(seekBar: SeekBar?) {
        println("triggered2")
    }

    override fun onStopTrackingTouch(seekBar: SeekBar?) {
        println("triggered3")
    }

    override fun onBindEditText(editText: EditText) {
        println("triggered4")
    }
}

root_preferences.xml

<PreferenceScreen xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto">

    <PreferenceCategory app:title="@string/messages_header">

        <EditTextPreference
            app:key="signature"
            app:title="@string/signature_title"
            app:useSimpleSummaryProvider="true" />

        <ListPreference
            app:defaultValue="reply"
            app:entries="@array/reply_entries"
            app:entryValues="@array/reply_values"
            app:key="reply"
            app:title="@string/reply_title"
            app:useSimpleSummaryProvider="true" />
        <SeekBarPreference
            android:key="seekbar_preference"
            android:title="Brightness"
            android:summary="@string/value_percentage"
            android:progress="0"
            app:showSeekBarValue="true" />

    </PreferenceCategory>

    <PreferenceCategory app:title="@string/sync_header">

        <SwitchPreferenceCompat
            app:key="sync"
            app:title="@string/sync_title" />

        <SwitchPreferenceCompat
            app:dependency="sync"
            app:key="attachment"
            app:summaryOff="@string/attachment_summary_off"
            app:summaryOn="@string/attachment_summary_on"
            app:title="@string/attachment_title" />

    </PreferenceCategory>

</PreferenceScreen>

解决方法

您必须使用OnPreferenceChangeListener

示例

val seekbarPreference: SeekBarPreference? = findPreference("seekbar_preference")
seekbarPreference!!.onPreferenceChangeListener =
    Preference.OnPreferenceChangeListener { preference,newValue ->
         println("triggered1")
        true
    }