Android--多媒体
a、加载大图片
public class MainActivity extends Activity {
private ImageView iv;
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout. activity_main);
iv = (ImageView) findViewById(R.id. iv);
}
public void loadbigpic(View v){
File file = new File(Environment.getExternalStorageDirectory(), "22.jpg");
Options opts= new Options();
opts. inJustDecodeBounds = true ;
BitmapFactory. decodeFile(file.getAbsolutePath(), opts);
//获取到图片的宽高
int outWidth = opts. outWidth;
int outHeigth = opts. outHeight;
Display display = getWindow().getWindowManager().getDefaultDisplay();
//获取手机屏幕的大小
int width = display. getWidth();
int height = display. getHeight();
int scaleX= outWidth/width;
int scaleY = outHeigth/height;
int scale = scaleX>scaleY?scaleX:scaleY;
if(scale<=0){
scale = 1;
}
opts. inSampleSize = scale;
opts. inJustDecodeBounds = false ;
Bitmap bitmap = BitmapFactory. decodeFile(file.getAbsolutePath(), opts);
iv.setImageBitmap(bitmap);
}
}
b、mp3播放
//一种方式
privatebooleanisplaying = false;
public void playMusic() {
if (isplaying ) {
return;
}
isplaying = true ;
mMp = MediaPlayer.create(getApplicationContext(), R.raw.qqqg);
mMp.start();
mMp.setOnCompletionListener(new MediaPlayer.OnCompletionListener() {
@Override
public void onCompletion(MediaPlayer mp) {
isplaying = false ;
}
});
}
//另一种方式
public class MainActivity extends Activity {
private MediaPlayer mp;
private EditText et_path ;
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout. activity_main);
et_path = (EditText) findViewById(R.id.et_path);
mp = new MediaPlayer();//媒体播放器
}
public void start(View v){
String path = et_path.getText().toString();
if(TextUtils. isEmpty(path)){
Toast. makeText(this, "歌曲路径不能为空", Toast.LENGTH_SHORT).show();
return;
}
mp.reset(); //重置
try {
mp.setDataSource(path);
prepareAsync();
} catch (Exception e) {
e.printStackTrace();
}
}
private void prepareAsync() {
mp.prepareAsync(); //异步准备
//从开始的位置开始播放
mp.seekTo(0);
//设置准备完成监听
mp.setOnPreparedListener( new MediaPlayer.OnPreparedListener() {
//准备完成
@Override
public void onPrepared(MediaPlayer mp) {
mp.start();
}
});
}
public void pausemoveon(View v){
Button bt = (Button)v;
if(mp .isPlaying()){//判断文件是否正在播放
//暂停 文字变成继续
mp.pause();
bt.setText( "继续");
} else{
//继续播放
mp.start();
bt.setText( "暂停");
}
}
public void stop(View v){
mp.stop();
}
public void replay(View v){
mp.stop();
prepareAsync();
}
@Override
protected void onDestroy() {
super.onDestroy();
mp.release(); //释放资源
mp = null;
}
}
c、mp4播放
public class MainActivity extends Activity {
private SurfaceView surfaceView;
private MediaPlayer mp ;
private EditText et_path ;
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout. activity_main);
et_path = (EditText) findViewById(R.id.et_path);
//找到视频播放的控件
surfaceView = (SurfaceView) findViewById(R.id.sv);
//进行初始化
surfaceView.getHolder().setType(SurfaceHolder.SURFACE_TYPE_PUSH_BUFFERS);//把视频直接显示出来
//保证手机的屏幕一直高亮（任何的控件都可以）
surfaceView.setKeepScreenOn(true);
mp = new MediaPlayer();
}
public void play(View v){
String path = et_path.getText().toString();
if(TextUtils. isEmpty(path)){
Toast. makeText(this, "播放文件的路径不能为空" , Toast.LENGTH_SHORT ).show();
return;
}
mp.reset();
try {
mp.setDataSource(path);
prepareAsync();
} catch (Exception e) {
e.printStackTrace();
}
}
private void prepareAsync() {
//把媒体播放器和SurfaceView关联起来
mp.setDisplay( surfaceView.getHolder());//设置显示
mp.prepareAsync();
mp.seekTo(0);
mp.setOnPreparedListener( new MediaPlayer.OnPreparedListener() {
@Override
public void onPrepared(MediaPlayer mp) {
mp.start();
}
});
}
public void pausemove(View v){
Button bt = (Button)v;
if(mp .isPlaying()){
mp.pause();
bt.setText( "继续");
} else{
mp.start();
bt.setText( "暂停");
}
}
public void stop(View v){
mp.stop();
}
public void replay(View v){
mp.stop();
prepareAsync();
}
@Override
protected void onDestroy() {
super.onDestroy();
mp.release();
mp = null;
}
}
d、拍照
public class MainActivity extends Activity {
private SurfaceView surfaceView ;
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout. activity_main);
surfaceView = (SurfaceView) findViewById(R.id.surfaceView);
surfaceView.setKeepScreenOn(true);// 保持屏幕高亮
// 获取SurfaceHolder
SurfaceHolder holder = surfaceView.getHolder();
// 让数据直接输出
holder. setType(SurfaceHolder.SURFACE_TYPE_PUSH_BUFFERS);
// 给SurfaceView 添加创建监听
holder.addCallback( new MyCallBack());
}
private Camera camera ;
private class MyCallBack implements Callback {
@Override
public void surfaceCreated(SurfaceHolder holder) {
/**
* 步骤： 1 打开相机 2 设置预览显示 3 开始预览
*/
try {
camera = Camera.open();
// 2 设置预览显示
camera.setPreviewDisplay(holder);
// 3 开始预览
camera.startPreview();
} catch (Exception e) {
e.printStackTrace();
}
}
@Override
public void surfaceChanged(SurfaceHolder holder, int format, int width,
int height) {}
@Override
public void surfaceDestroyed(SurfaceHolder holder) {
camera.release();// 释放硬件资源
camera = null ;
}
}
public void focus(View v) {
// 对焦
camera.autoFocus(null);// 自动对焦都是硬件来完成
}
public void takepictrue(View v) {
// 拍照
// shutter 快门, raw 相机捕获的原始数据, jpeg 相机处理后的数据 其实这三个参数都是接口
camera.takePicture(null, null, new MyPictureCallback());
}
// 相机处理完成照片后的监听类
private class MyPictureCallback implements PictureCallback {
// 处理完成照片后 自动调用该方法 相机只能同时干一件事件 在处理照片的时候 相机是被占用的
@Override
public void onPictureTaken(byte[] data, Camera camera) {
try {
// 把相机的数据保存在 sdcard 权限
File file = new File(Environment.getExternalStorageDirectory(),
"sz08.jpg");
FileOutputStream fos = new FileOutputStream(file);
fos.write(data);
fos.close();
// 重新预览
camera.startPreview();
} catch (Exception e) {
e.printStackTrace();
}
}
}
}