安卓app，MediaPlayer播放本地音频 | 按钮控制播放和停止

import android.content.Context  
import android.media.MediaPlayer  
import androidx.lifecycle.MutableLiveData  
import androidx.lifecycle.ViewModel  
  
class AudioPlayerViewModel : ViewModel() {  
    private var mediaPlayer: MediaPlayer? = null  
  
    // 播放状态  
    val isPlaying = MutableLiveData<Boolean>(false)  
  
    // 初始化MediaPlayer并准备播放  
    fun initPlayer(context: Context, audioResourceId: Int) {  
        mediaPlayer = MediaPlayer.create(context, audioResourceId)  
        mediaPlayer?.setOnPreparedListener {  
            isPlaying.value = false  
        }  
    }  
  
    // 播放音频  
    fun play() {  
        mediaPlayer?.start()  
        isPlaying.value = true  
    }  
  
    // 暂停音频  
    fun pause() {  
        mediaPlayer?.pause()  
        isPlaying.value = false  
    }  
  
    // 停止并释放MediaPlayer  
    fun stopAndRelease() {  
        mediaPlayer?.stop()  
        mediaPlayer?.release()  
        mediaPlayer = null  
        isPlaying.value = false  
    }  
  
    // 检查是否正在播放  
    fun isCurrentlyPlaying(): Boolean {  
        return mediaPlayer?.isPlaying ?: false  
    }  
}

import android.content.Context  
import androidx.activity.ComponentActivity  
import androidx.activity.compose.setContent  
import androidx.compose.foundation.layout.*  
import androidx.compose.runtime.*  
import androidx.compose.ui.Modifier  
import androidx.compose.ui.tooling.preview.Preview  
import androidx.lifecycle.ViewModelProvider  
import androidx.lifecycle.viewmodel.compose.viewModel  
import com.google.accompanist.insets.navigationBarsPadding  
import com.google.accompanist.insets.statusBarsPadding  
  
@Composable  
fun AudioPlayerScreen(context: Context) {  
    val viewModel: AudioPlayerViewModel = viewModel()  
  
    viewModel.initPlayer(context, R.raw.your_audio_file) // 替换为你的音频文件资源ID  
  
    BoxWithConstraints(  
        modifier = Modifier  
            .fillMaxSize()  
            .statusBarsPadding()  
            .navigationBarsPadding()  
    ) {  
        Column(  
            modifier = Modifier  
                .fillMaxSize()  
                .padding(16.dp),  
            verticalArrangement = Arrangement.Center,  
            horizontalAlignment = Alignment.CenterHorizontally  
        ) {  
            Button(  
                onClick = {  
                    if (viewModel.isCurrentlyPlaying()) {  
                        viewModel.pause()  
                    } else {  
                        viewModel.play()  
                    }  
                }  
            ) {  
                Text(  
                    if (viewModel.isPlaying.value == true) "Pause" else "Play",  
                    style = MaterialTheme.typography.button  
                )  
            }  
  
            // 这里可以添加更多UI元素，如播放进度条等  
        }  
    }  
  
    // 清理MediaPlayer资源  
    DisposableEffect(Unit) {  
        onDispose {  
            viewModel.stopAndRelease()  
        }  
    }  
}  
  
@Preview(showBackground = true)  
@Composable  
fun DefaultPreview() {  
    AudioPlayerScreen(LocalContext.current)  
}  
  
// 在你的Activity中设置Compose UI  
class MainActivity : ComponentActivity() {  
    override fun onCreate(savedInstanceState: Bundle?) {  
        super.onCreate(savedInstanceState)  
        setContent {  
            AudioPlayerScreen(this)  
        }  
    }  
}

import android.media.MediaPlayer
import androidx.compose.foundation.layout.Column
import androidx.compose.foundation.layout.fillMaxSize
import androidx.compose.material.Button
import androidx.compose.material.Text
import androidx.compose.runtime.Composable
import androidx.compose.runtime.LaunchedEffect
import androidx.compose.runtime.getValue
import androidx.compose.runtime.mutableStateOf
import androidx.compose.runtime.remember
import androidx.compose.runtime.setValue
import androidx.compose.ui.Modifier
import kotlinx.coroutines.delay

@Composable
fun MediaPlayerDemo() {
    var mediaPlayer by remember { mutableStateOf<MediaPlayer?>(null) }
    var isPlaying by remember { mutableStateOf(false) }

    LaunchedEffect(key1 = true) {
        mediaPlayer = MediaPlayer.create(LocalContext.current, R.raw.your_audio_file)
        mediaPlayer?.setOnCompletionListener {
            isPlaying = false
        }
    }

    Column(modifier = Modifier.fillMaxSize()) {
        Button(
            onClick = {
                if (!isPlaying && mediaPlayer != null) {
                    mediaPlayer?.start()
                    isPlaying = true
                }
            },
            enabled = !isPlaying
        ) {
            Text(text = "Play")
        }
        Button(
            onClick = {
                if (isPlaying && mediaPlayer != null) {
                    mediaPlayer?.pause()
                    isPlaying = false
                }
            },
            enabled = isPlaying
        ) {
            Text(text = "Stop")
        }
    }
}