一、播放音频的API
1.1 MediaPlay
public void play(View v) {
String path = et_path.getText().toString();
//1.判空操作，2，判断是否真的存在这个文件，有可能用户输入的是非法的文件路径
try {
//1，创建一个多媒体播放器
mediaPlayer = new MediaPlayer();
//2.设置播放资源
mediaPlayer.setDataSource(path);
//设置播放错误监听--一般是音频文件损坏了。。
/* mediaPlayer.setOnErrorListener(new OnErrorListener() {
@Override
public boolean onError(MediaPlayer mp, int what, int extra) {
return false;
}
});*/
//3.准备一下
mediaPlayer.prepare();
//4. 开始播放
mediaPlayer.start();
//播放完毕的监听，如果已经播放完毕，那么可以播放下一首歌，或者继续播放当前的这首歌
mediaPlayer.setOnCompletionListener(new OnCompletionListener() {
@Override
public void onCompletion(MediaPlayer mp) {
mediaPlayer.seekTo(0);
mediaPlayer.start();
}
});
} catch (Exception e) {
e.printStackTrace();
}
}
public void pause(View v) {
if(mediaPlayer.isPlaying()){
mediaPlayer.pause();
}else{
mediaPlayer.start();
}
}1.2 SoundPool ---声音池
一般用来播放游戏的音效，大量密集的出现的时候
public class MainActivity extends Activity {
int id ;
SoundPool pool ;
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
pool = new SoundPool(
3, //最多能放多少道音频文件
AudioManager.STREAM_MUSIC, // 存储的流类型是什么类型
0); //没有生命影响，给0
//加载音频文件到池子里面。
id = pool.load(this, R.raw.shoot, 1);
}
public void shoot(View v){
pool.play(id, 1, 1, 0, 0, 1.0f);
}
}1.3 视频播放
public class MainActivity extends Activity {
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
//1.找到播放视频的控件
VideoView vv = (VideoView) findViewById(R.id.vv);
//2.指定播放的视频源
vv.setVideoPath("/mnt/sdcard/oppo.3gp");
MediaController controller = new MediaController(this);
controller.setAnchorView(vv);
//设置视频的控制器 暂停、播放、快进、快退
vv.setMediaController(controller);
//3.开始播放
vv.start();
}
}二、SurfaceView
（1）可以单位时间内大量的渲染、显示不同的画面
（2）内部使用的是双缓冲机制
（3）surfaceView是一个比较耗费内存的控件，系统不会一开始上来就渲染这个 控件，而是等界面能够看到的时候才去渲染这个控件，才去显示它。那由于一开始就在onCreate方法里面 ，所以画布是空的。
2.1 在子线程中更新UI
/**
* surfaceView使用的是双缓冲的机制，所以可以单位时间内更新大量的画面
*
* 线程0： 显示画面---计算数据 ---显示画面
* 线程1： 计算数据----显示画面---计算数据
*
* 可以在子线程里面更新UI ProgressBar 进度条
*
*/
public class MainActivity extends Activity {
SurfaceView sv ;
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
sv = (SurfaceView) findViewById(R.id.sv);
new Thread(){
public void run() {
SystemClock.sleep(1000);
//获取到surfaceview的控制器
SurfaceHolder holder = sv.getHolder();
int radius = 5;
for (int i = 0; i < 10; i++) {
//由于界面没显示，所以画布是空的。
Canvas canvas = holder.lockCanvas();
canvas.drawColor(Color.BLACK);
Paint paint = new Paint();
paint.setColor(Color.RED);
radius +=i;
canvas.drawCircle(100, 100, radius, paint);
//解锁画布
holder.unlockCanvasAndPost(canvas);
SystemClock.sleep(100);
}
};
}.start();
}
public void update(View v){
new Thread(){
public void run() {
//获取到surfaceview的控制器
SurfaceHolder holder = sv.getHolder();
int radius = 5;
for (int i = 0; i < 10; i++) {
Canvas canvas = holder.lockCanvas();
canvas.drawColor(Color.BLACK);
Paint paint = new Paint();
paint.setColor(Color.RED);
radius +=i;
canvas.drawCircle(100, 100, radius, paint);
//解锁画布
holder.unlockCanvasAndPost(canvas);
SystemClock.sleep(100);
}
};
}.start();
}
}2.2 SurfaceView的生命周期
SurfaceView可见的时候执行SurfaceCreate方法，不可见的时候调用SurfaceDestroy方法。
/**
* surfaceView使用的是双缓冲的机制，所以可以单位时间内更新大量的画面
*
* 线程0： 显示画面---计算数据 ---显示画面
* 线程1： 计算数据----显示画面---计算数据
*
* 可以在子线程里面更新UI ProgressBar 进度条
*
*/
public class MainActivity extends Activity {
SurfaceView sv ;
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
sv = (SurfaceView) findViewById(R.id.sv);
//1.得到surfaceView的控制器
SurfaceHolder holder = sv.getHolder();
holder.addCallback(new Callback() {
//当surfaceView销毁的时候调用
@Override
public void surfaceDestroyed(SurfaceHolder holder) {
System.out.println("---surfaceDestroyed--");
}
//当surfaceView创建的时候调用
@Override
public void surfaceCreated(final SurfaceHolder holder) {
System.out.println("---surfaceCreated--"+Thread.currentThread().getName());
//获取到surfaceview的控制器
//SurfaceHolder holder = sv.getHolder();
new Thread(){
public void run() {
int radius = 5;
for (int i = 0; i < 10; i++) {
//由于界面没显示，所以画布是空的。
Canvas canvas = holder.lockCanvas();
canvas.drawColor(Color.BLACK);
Paint paint = new Paint();
paint.setColor(Color.RED);
radius +=i;
canvas.drawCircle(100, 100, radius, paint);
//解锁画布
holder.unlockCanvasAndPost(canvas);
SystemClock.sleep(100);
}
};
}.start();
}
//当surfaceView发生改变的时候调用
@Override
public void surfaceChanged(SurfaceHolder holder, int format, int width,
int height) {
System.out.println("---surfaceChanged--");
}
});
/*
new Thread(){
public void run() {
SystemClock.sleep(1000);
//获取到surfaceview的控制器
SurfaceHolder holder = sv.getHolder();
int radius = 5;
for (int i = 0; i < 10; i++) {
//由于界面没显示，所以画布是空的。
Canvas canvas = holder.lockCanvas();
canvas.drawColor(Color.BLACK);
Paint paint = new Paint();
paint.setColor(Color.RED);
radius +=i;
canvas.drawCircle(100, 100, radius, paint);
//解锁画布
holder.unlockCanvasAndPost(canvas);
SystemClock.sleep(100);
}
};
}.start();*/
}
public void update(View v){
new Thread(){
public void run() {
//获取到surfaceview的控制器
SurfaceHolder holder = sv.getHolder();
int radius = 5;
for (int i = 0; i < 10; i++) {
Canvas canvas = holder.lockCanvas();
canvas.drawColor(Color.BLACK);
Paint paint = new Paint();
paint.setColor(Color.RED);
radius +=i;
canvas.drawCircle(100, 100, radius, paint);
//解锁画布
holder.unlockCanvasAndPost(canvas);
SystemClock.sleep(100);
}
};
}.start();
}
}2.3 SurfaceView播放视频
public class MainActivity extends Activity {
MediaPlayer mediaPlayer;
SharedPreferences sp ;
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
sp = getSharedPreferences("config", 0);
SurfaceView sv = (SurfaceView) findViewById(R.id.sv);
sv.getHolder().addCallback(new Callback() {
@Override
public void surfaceDestroyed(SurfaceHolder holder) {
if(mediaPlayer != null){
//获取到当前的播放位置
int position = mediaPlayer.getCurrentPosition();
Editor editor = sp.edit();
editor.putInt("position", position);
editor.commit();
mediaPlayer.release();
mediaPlayer = null;
}
}
@Override
public void surfaceCreated(SurfaceHolder holder) {
//应该在这个地方去播放视频了。
try {
int position = sp.getInt("position", 0);
mediaPlayer = new MediaPlayer();
mediaPlayer.setDataSource("/mnt/sdcard/oppo.3gp");
mediaPlayer.prepare();
//指定播放的画面显示到holder里面去，实际上就是显示到surfaceView里面去
mediaPlayer.setDisplay(holder);
mediaPlayer.seekTo(position);
mediaPlayer.start();
} catch (Exception e) {
e.printStackTrace();
}
}
@Override
public void surfaceChanged(SurfaceHolder holder, int format, int width,
int height) {
}
});
}
}三、拍照
public class MainActivity extends Activity {
File file ;
ImageView iv ;
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
iv = (ImageView)findViewById(R.id.iv);
}
public void click(View v){
// create Intent to take a picture and return control to the calling application
Intent intent = new Intent(MediaStore.ACTION_IMAGE_CAPTURE);
// fileUri = getOutputMediaFileUri(MEDIA_TYPE_IMAGE); // create a file to save the image
file = new File("/mnt/sdcard/"+System.currentTimeMillis()+".jpg");
Uri fileUri = Uri.fromFile(file);
//这个传递的数值代表的意思是：告诉系统照相机，拍完照片之后，把那张照片保存到给你的uri路径下
intent.putExtra(MediaStore.EXTRA_OUTPUT, fileUri); // set the image file name
// start the image capture Intent
startActivityForResult(intent, 1);
}
@Override
protected void onActivityResult(int requestCode, int resultCode, Intent data) {
//转化图片
if(file != null){
Bitmap bitmap = BitmapFactory.decodeFile(file.getAbsolutePath());
iv.setImageBitmap(bitmap);
}
}
}四、录制视频
public class MainActivity extends Activity {
File file ;
VideoView vv ;
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
vv = (VideoView)findViewById(R.id.vv);
}
public void click(View v){
// create Intent to take a picture and return control to the calling application
Intent intent = new Intent(MediaStore.ACTION_VIDEO_CAPTURE);
// fileUri = getOutputMediaFileUri(MEDIA_TYPE_IMAGE); // create a file to save the image
file = new File("/mnt/sdcard/"+System.currentTimeMillis()+".3gp");
Uri fileUri = Uri.fromFile(file);
//这个传递的数值代表的意思是：告诉系统照相机，拍完照片之后，把那张照片保存到给你的uri路径下
intent.putExtra(MediaStore.EXTRA_OUTPUT, fileUri); // set the image file name
intent.putExtra(MediaStore.EXTRA_VIDEO_QUALITY, 1); // set the video image quality to high
// start the image capture Intent
startActivityForResult(intent, 1);
}
@Override
protected void onActivityResult(int requestCode, int resultCode, Intent data) {
//转化图片
if(file != null){
vv.setVideoPath(file.getAbsolutePath());
MediaController controller = new MediaController(this);
controller.setAnchorView(vv);
vv.setMediaController(controller);
vv.start();
}
}
}
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