Android : 片段中的 startActionMode 仅在 onActivityCreated 内部有效

Question

我有一个使用 RecyclerView 的片段。该片段从适配器 class.

实现 onClickListener

在片段中，我想在单击 recyclerView 项目时调用 startActionMode。

startActionMode 在 onActicityCreated 方法中有效，但在 onClickListener.

中无效

下面是代码：

SongsFrament.kt

package com.akshat.music

import android.content.ContentUris
import android.net.Uri
import android.os.Bundle
import android.provider.MediaStore
import android.view.*
import androidx.fragment.app.Fragment
import androidx.recyclerview.widget.LinearLayoutManager
import kotlinx.android.synthetic.main.fragment_songs.*
import java.io.File

class SongsFragment : Fragment(), SongListAdapter.OnItemClickListener, ActionMode.Callback {

    private val allSongs = ArrayList<Songs>()

    override fun onActivityCreated(savedInstanceState: Bundle?) {
        super.onActivityCreated(savedInstanceState)
        recyclerView.apply {
            layoutManager = LinearLayoutManager(activity)
            adapter = SongListAdapter(allSongs, SongsFragment())
        }
        activity?.startActionMode(this)   // this works 
    }

    override fun onCreate(savedInstanceState: Bundle?) {
        super.onCreate(savedInstanceState)
        getAudioDirectories()
    }

    override fun onCreateView(
        inflater: LayoutInflater,
        container: ViewGroup?,
        savedInstanceState: Bundle?
    ): View? {
        return inflater!!.inflate(R.layout.fragment_songs, container, false);
    }

    override fun onItemClicked(song: Songs, position: Int) {
        activity?.startActionMode(this@SongsFragment) // this doesn't work
    }

    override fun onActionItemClicked(p0: ActionMode?, p1: MenuItem?): Boolean {
        return false
    }

    override fun onCreateActionMode(p0: ActionMode?, p1: Menu?): Boolean {
        activity?.menuInflater?.inflate(R.menu.contextual_action_bar, p1)
        return true
    }

    override fun onPrepareActionMode(p0: ActionMode?, p1: Menu?): Boolean {
        return true
    }

    override fun onDestroyActionMode(p0: ActionMode?) {
    }

    private fun getAudioDirectories() {

        val uri = MediaStore.Audio.Media.EXTERNAL_CONTENT_URI
        val selection = MediaStore.Audio.Media.IS_MUSIC + "!=0"
        val order = MediaStore.Audio.Media.DISPLAY_NAME + " ASC"
        val cursor = activity?.contentResolver?.query(uri, null, selection, null, order)

        cursor?.let {
            it.moveToFirst()
            val pathIndex = it.getColumnIndex(MediaStore.Images.Media.DATA)
            do {
                val path = it.getString(pathIndex)

                val file = File(path)
                if (!file.exists()) {
                    continue
                }
                var songAuth = it.getString(it.getColumnIndex(MediaStore.Audio.Media.ARTIST))
                var songName = it.getString(it.getColumnIndex(MediaStore.Audio.Media.TITLE))
                val albumID = it.getLong(it.getColumnIndex(MediaStore.Audio.Albums.ALBUM_ID))
                val sArtworkUri = Uri.parse("content://media/external/audio/albumart")
                val albumArtUri = ContentUris.withAppendedId(sArtworkUri, albumID)

                var song = Songs(songName, songAuth, albumArtUri)
                allSongs.add(song)

            } while (it.moveToNext())

        }
    }
}

如何让 startActionMode 在 onItemClicked 中工作？

Answer 1

您可能忘记将片段作为 OnItemClickListener 传递到 adpter 中。尝试这样的事情：

override fun onActivityCreated(savedInstanceState: Bundle?) {
super.onActivityCreated(savedInstanceState)
recyclerView.apply {
    layoutManager = LinearLayoutManager(activity)
    adapter = SongListAdapter(allSongs, SongsFragment()).apply {
        onItemClickListener = this
    }
}
activity?.startActionMode(this)   // this works

Android : 片段中的 startActionMode 仅在 onActivityCreated 内部有效

Android : startActionMode in fragment only works inside onActivityCreated

android

android-fragments

kotlin

android-actionmode