setTargetFragment() 现在已被弃用，如何替换它

Question

setTargetFragment() 在 Java 中被弃用，我不明白它的正确替代品，因为 android 文档使用它并且已经过时。我相信 FragmentManager 是它的正确替代品。我在设置首选项中使用已弃用的 setTargetFragment 函数来创建多个首选项屏幕。为此，我最初遵循指南 here，该指南在示例中混淆地使用了 setTargetFragment。下面是我的代码：

build.gradle (Module: app)
...
implementation 'androidx.appcompat:appcompat:1.2.0'
implementation 'androidx.constraintlayout:constraintlayout:2.0.4'
implementation 'androidx.preference:preference:1.1.1'
...

MainActivity.kt

class MainActivity : AppCompatActivity() {
    private lateinit var settingsButton: ImageButton

    override fun onCreate(savedInstanceState: Bundle?) {
        ...
        settingsButton = findViewById(R.id.settingsButtonMain)
        settingsButton.setOnClickListener {
            settingsClicked()
        }
        ...
    }

    private fun settingsClicked() {
        val settingsIntent = Intent(this, SettingsActivity::class.java)
        startActivity(settingsIntent)
    }
}

SettingsActivity.kt

class SettingsActivity : AppCompatActivity(), PreferenceFragmentCompat.OnPreferenceStartFragmentCallback {
    override fun onCreate(savedInstanceState: Bundle?) {
        ...
        supportFragmentManager.beginTransaction().replace(R.id.settings, SettingsFragment(this)).commit()
        supportFragmentManager.addOnBackStackChangedListener {
            if(supportFragmentManager.backStackEntryCount == 0) {
                title = "App Settings"
            }
        }
        supportActionBar?.setDisplayHomeAsUpEnabled(true)
        ...
    }

    class SettingsFragment(cont: Context) : PreferenceFragmentCompat() {
        private var context1: Context = cont

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

    class Screen2PreferencesFragment : PreferenceFragmentCompat() {
        override fun onCreatePreferences(savedInstanceState: Bundle?, rootKey: String?) {
            setPreferencesFromResource(R.xml.screen2_preferences, null)
        }
    }

    override fun onPreferenceStartFragment(caller: PreferenceFragmentCompat?, pref: Preference): Boolean {
        val args: Bundle = pref.extras
        val fragment: Fragment = supportFragmentManager.fragmentFactory.instantiate(classLoader, pref.fragment)
        fragment.arguments = args
        fragment.setTargetFragment(caller, 0) //TROUBLE AREA. WHAT IS THE CORRECT REPLACEMENT HERE?
        supportFragmentManager.beginTransaction().replace(R.id.settings, fragment).addToBackStack(null).commit()
        return true
    }

    override fun onSupportNavigateUp(): Boolean {
        if(supportFragmentManager.popBackStackImmediate()) {
            return true
        }
        return super.onSupportNavigateUp()
    }
}

Answer 1

包括这个依赖项：

implementation 'androidx.fragment:fragment-ktx:1.3.0-beta01'

使用setFragmentResultListener代替setTargetFragment()：

override fun onPreferenceStartFragment(caller: PreferenceFragmentCompat?, pref: Preference): Boolean {
    val args: Bundle = pref.extras
    val fragment: Fragment = supportFragmentManager.fragmentFactory.instantiate(classLoader, pref.fragment)
    fragment.arguments = args
    supportFragmentManager.beginTransaction().replace(R.id.settings, fragment).addToBackStack(null).commit()
    
    supportFragmentManager.setFragmentResultListener("requestKey") { key, bundle ->
        if (key == "requestKey") {
            // Get result from bundle
        }
    }
    
    return true
}

在你的片段中 returns 结果是：

// Insert result in a bundle
setFragmentResult("requestKey", bundle)

Answer 2

参考上面的回答，尝试使用setFragmentResult时未解决的问题，您可以尝试使用fragmentManager如下。

这是 Xamarin 的：

ParentFragmentManager.SetFragmentResult("requestKey", bundle);

setTargetFragment() 现在已被弃用，如何替换它

How to replace setTargetFragment() now that it is deprecated

android

android-fragments

androidx

android-preferences