之前参与过一个项目，开发的是一个系统级别的软件，安装在定制的设备上，设备没有控制音量的按键，因此软件需要实现一个在任意页面都能控制音量的功能。
实现方案是在所有页面的顶部加上一个触发音量控制弹窗的按钮，用户点击该按钮后显示音量控制弹窗。
参与项目时，已经出了第一版了，包含的页面很多，因此一个个页面去加肯定不合适。项目中所有Activity都继承了一个自定义的BaseActivity，所以只能在这个BaseActivity中做文章。
Android中，每个Activity都包含一个DecorView，DecorView内部包含一个FrameLayout，可以通过android.R.id.content来获取，我们的布局包含在这个FrameLayout中。
因此如果需要在所有的页面都添加View，那么在BaseActivity中实现向android.R.id.content对应的FrameLayout添加View的逻辑，然后所有的Activity就都可以自动添加View了。
实现代码如下：
object DensityUtil {
@JvmStatic
fun dp2Px(dpValue: Int): Int {
return TypedValue.applyDimension(TypedValue.COMPLEX_UNIT_DIP, dpValue.toFloat(), Resources.getSystem().displayMetrics).toInt()
}
@JvmStatic
fun px2Dp(pxValue: Int): Int {
return TypedValue.applyDimension(TypedValue.COMPLEX_UNIT_PX, pxValue.toFloat(), Resources.getSystem().displayMetrics).toInt()
}
}
// Base类
open class BaseActivity : AppCompatActivity() {
override fun onResume() {
super.onResume()
// 在onResume中添加，确保在主布局添加完成后添加，避免被遮挡。
initVolumeControllerView()
}
private fun initVolumeControllerView() {
val controllerView = AppCompatImageView(this)
controllerView.layoutParams = FrameLayout.LayoutParams(DensityUtil.dp2Px(80), DensityUtil.dp2Px(12)).apply {
gravity = Gravity.START
marginStart = DensityUtil.dp2Px(20)
topMargin = DensityUtil.dp2Px(10)
}
controllerView.setImageResource(R.drawable.shape_vollume_controller)
controllerView.setOnClickListener {
runOnUiThread { Toast.makeText(this, "点击了全局按钮", Toast.LENGTH_SHORT).show() }
}
val rootView = findViewById<FrameLayout>(android.R.id.content)
rootView.addView(controllerView)
}
}
效果如图：
AudioManager类提供了控制音量的方法。
实现音量控制代码如下：
class VolumeControllerDialog : DialogFragment() {
private var binding: LayoutVolumeContollerDialogBinding? = null
private var currentVolume = 0
override fun onCreateView(inflater: LayoutInflater, container: ViewGroup?, savedInstanceState: Bundle?): View? {
dialog?.window?.run {
setBackgroundDrawable(ContextCompat.getDrawable(requireContext(), android.R.color.transparent))
decorView.setBackgroundResource(android.R.color.transparent)
val layoutParams = attributes
layoutParams.width = DensityUtil.dp2Px(360)
layoutParams.height = WindowManager.LayoutParams.WRAP_CONTENT
layoutParams.gravity = Gravity.CENTER
attributes = layoutParams
}
binding = DataBindingUtil.inflate(inflater, R.layout.layout_volume_contoller_dialog, container, false)
return binding?.root
}
override fun onViewCreated(view: View, savedInstanceState: Bundle?) {
super.onViewCreated(view, savedInstanceState)
val audioManager = requireContext().getSystemService(Context.AUDIO_SERVICE) as AudioManager
currentVolume = audioManager.getStreamVolume(AudioManager.STREAM_MUSIC)
val step = 1
binding?.run {
btnMute.text = getMuteButtonString(audioManager.isStreamMute(AudioManager.STREAM_MUSIC))
btnIncreaseVolume.setOnClickListener {
// 增加音量
currentVolume = audioManager.getStreamVolume(AudioManager.STREAM_MUSIC)
audioManager.setStreamVolume(AudioManager.STREAM_MUSIC, currentVolume + step, AudioManager.FLAG_SHOW_UI or AudioManager.FLAG_PLAY_SOUND)
btnMute.text = getMuteButtonString(audioManager.isStreamMute(AudioManager.STREAM_MUSIC))
}
btnReduceVolume.setOnClickListener {
//减少音量
currentVolume = audioManager.getStreamVolume(AudioManager.STREAM_MUSIC)
audioManager.setStreamVolume(AudioManager.STREAM_MUSIC, if (currentVolume - step < 0) 0 else currentVolume - step, AudioManager.FLAG_SHOW_UI or AudioManager.FLAG_PLAY_SOUND)
btnMute.text = getMuteButtonString(audioManager.isStreamMute(AudioManager.STREAM_MUSIC))
}
btnMute.setOnClickListener {
// 静音或取消静音
val currentMute = audioManager.isStreamMute(AudioManager.STREAM_MUSIC)
if (currentVolume == 0) {
btnMute.text = getMuteButtonString(true)
} else {
btnMute.text = getMuteButtonString(!currentMute)
}
val setVolume = if (currentMute) {
currentVolume
} else {
currentVolume = audioManager.getStreamVolume(AudioManager.STREAM_MUSIC)
0
}
audioManager.setStreamVolume(AudioManager.STREAM_MUSIC, setVolume, AudioManager.FLAG_SHOW_UI or AudioManager.FLAG_PLAY_SOUND)
}
}
}
private fun getMuteButtonString(mute: Boolean): String {
return if (mute) "UnMute" else "Mute"
}
}
open class BaseActivity : AppCompatActivity() {
override fun onResume() {
super.onResume()
// 在onResume中添加，确保在主布局添加完成后添加，避免被遮挡。
initVolumeControllerView()
}
private fun initVolumeControllerView() {
val controllerView = AppCompatImageView(this)
controllerView.layoutParams = FrameLayout.LayoutParams(DensityUtil.dp2Px(80), DensityUtil.dp2Px(12)).apply {
gravity = Gravity.START
marginStart = DensityUtil.dp2Px(20)
topMargin = DensityUtil.dp2Px(10)
}
controllerView.setImageResource(R.drawable.shape_vollume_controller)
controllerView.setOnClickListener {
VolumeControllerDialog().show(supportFragmentManager, null)
}
val rootView = findViewById<FrameLayout>(android.R.id.content)
rootView.addView(controllerView)
}
}
效果如图：
