Android音乐播放声音淡入淡出的实现
思路： 调用如下API接口
MediaPlayer.setVolume(left, right);// 左右声道，值为0~1
比如，让音量从 0 增加到100%，分为10次增加，则可以调10次上面的接口（每次间隔0.2秒，一共2秒内音量增加到100%），如下所示：
MediaPlayer.setVolume(0.1, 0.1); MediaPlayer.setVolume(0.2, 0.2); MediaPlayer.setVolume(0.3, 0.3); ... MediaPlayer.setVolume(1.0, 1.0); // 音量100%
实现方式一，通过 android.os.Handler 发送 android.os.Message 消息，代码如下：
import android.os.Handler;
import android.os.Message;
public class MuteVolumeManager {
// action
private static final int ACTION_RESTORE_VALUE = 1000;
private static final int ACTION_STOP_VALUE = 1001;
// 淡出与淡出时间
private int restoreTime = 5000; // 恢复 淡入时间为5秒
private int stopTime = 1000; // 静音 淡出时间为1秒
private float muteCurVolume = 0f;
private float muteTargetVolume = 0f;
private float unMuteCurVolume = 0f;
private float unMuteTargetVolume = 0f;
private boolean isMuteing = false;
private boolean isUnMuteing = false;
// listenter
private VolumeListenter volumeListenter;
// handler control
private Handler handler = new Handler() {
@Override
public void handleMessage(Message msg) {
super.handleMessage(msg);
if (msg.what == ACTION_RESTORE_VALUE) {
if (muteCurVolume < muteTargetVolume) {
muteCurVolume += 0.1f;
if (muteCurVolume > 1) {
muteCurVolume = 1;
}
// Logger.d("siven","实时恢复音量 " + muteCurVolume);
if (muteCurVolume < muteTargetVolume) {
notifyVolumeChange(muteCurVolume);// 最大1.0,是个百分比
handler.sendEmptyMessageDelayed(ACTION_RESTORE_VALUE, restoreTime / 10);
} else {
muteCurVolume = muteTargetVolume;
notifyVolumeChange(muteCurVolume);// 最大1.0,是个百分比
if (volumeListenter != null &&
isUnMuteing) volumeListenter.onCompleteUnMute(muteCurVolume);
isUnMuteing = false;
}
} else if (muteCurVolume >= muteTargetVolume) {
notifyVolumeChange(muteTargetVolume); //最大1.0,是个百分比
// Logger.d("siven","实时恢复音量 " + muteTargetVolume);
if (volumeListenter != null &&
isUnMuteing) volumeListenter.onCompleteUnMute(muteCurVolume);
isUnMuteing = false;
}
} else if (msg.what == ACTION_STOP_VALUE) {
if (unMuteCurVolume > unMuteTargetVolume) {
unMuteCurVolume -= 0.1;
if (unMuteCurVolume < 0) {
unMuteCurVolume = 0;
}
notifyVolumeChange(unMuteCurVolume);
// Logger.d("siven","实时静音音量 " + unMuteCurVolume);
if (unMuteCurVolume > unMuteTargetVolume) {
handler.sendEmptyMessageDelayed(ACTION_STOP_VALUE, stopTime / 10);//0.5秒恢复音量100%音量
} else {
if (volumeListenter != null &&
isMuteing) volumeListenter.onCompleteMute(unMuteCurVolume);
isMuteing = false;
}
} else {
notifyVolumeChange(0f);//静音
if (volumeListenter != null &&
isMuteing) volumeListenter.onCompleteMute(unMuteCurVolume);
isMuteing = false;
}
}
}
};
public void setVolumeListenter(VolumeListenter volumeListenter) {
this.volumeListenter = volumeListenter;
}
/**
* 恢复音量,淡入效果
*/
public void unMute(float curVolume, float tagetVolume) {
if (isUnMuteing) return;
isUnMuteing = true;
this.muteTargetVolume = tagetVolume;
this.muteCurVolume = curVolume;
handler.sendEmptyMessage(ACTION_RESTORE_VALUE);
}
/**
* 静音,淡出效果
*/
public void mute(float curVolume) {
if (isMuteing) return;
isMuteing = true;
this.unMuteCurVolume = curVolume;
this.unMuteTargetVolume = 0f;
handler.sendEmptyMessage(ACTION_STOP_VALUE);
}
private void notifyVolumeChange(float volume) {
if (volumeListenter != null) {
volumeListenter.onVolumeChange(volume);
}
}
public interface VolumeListenter {
void onCompleteMute(float curVolume);
void onCompleteUnMute(float curVolume);
void onVolumeChange(float volume);
}
}调用方法示例如下：
mMediaPlayer.start();
setVolumeFade(mMediaPlayer);
mMediaPlayer.setVolume(0f, 0f);
volumeManager.unMute(0f, 1f);
private void setVolumeFade(final IjkMediaPlayer mediaPlayer) {
volumeManager.setVolumeListenter(new MuteVolumeManager.VolumeListenter() {
public void onCompleteMute(float curVolume) {
Log.i("siven", "静音完成,当前音量为: " + curVolume);
}
public void onCompleteUnMute(float curVolume) {
Log.i("siven", "恢复音量完成,当前音量为: " + curVolume);
}
public void onVolumeChange(float volume) {
if (mediaPlayer != null) {
// 动态设置音量
mediaPlayer.setVolume(volume, volume);
}
}
});
}实现方式二，使用 android.animation.ValueAnimator 淡入淡出工具类，如下：
import android.animation.Animator;
import android.animation.ValueAnimator;
import android.media.MediaPlayer;
import android.support.annotation.Nullable;
import android.view.animation.LinearInterpolator;
/**
* 音量淡入
*/
public class FadeIn {
public static void volumeGradient(final MediaPlayer mediaPlayer,
final float from, final float to) {
ValueAnimator animator = ValueAnimator.ofFloat(from, to);
animator.setDuration(6000); // 淡入时间
animator.setInterpolator(new LinearInterpolator());
animator.addUpdateListener(new ValueAnimator.AnimatorUpdateListener() {
public void onAnimationUpdate(ValueAnimator it) {
float volume = (float) it.getAnimatedValue();
try {
// 此时可能 mediaPlayer 状态发生了改变
//,所以用try catch包裹,一旦发生错误,立马取消
mediaPlayer.setVolume(volume, volume);
} catch (Exception e) {
it.cancel();
}
}
});
animator.addListener(new Animator.AnimatorListener() {
@Override
public void onAnimationStart(Animator animation) {
}
@Override
public void onAnimationEnd(Animator animation) {
// mediaPlayer.setVolume(from, from);
// if (doneCallBack != null) {
// doneCallBack.onComplete();
// }
}
@Override
public void onAnimationCancel(Animator animation) {
// try {
// mediaPlayer.setVolume(from, from);
// } catch (Exception e) {
// //忽略
// }
}
@Override
public void onAnimationRepeat(Animator animation) {
}
});
animator.start();
}
}调用方法如下：
FadeIn.volumeGradient(mMediaPlayer, 0f, 1f);
推荐使用第二种方式。