相机Camera

Camera需与SurfaceView配合使用

Camera类常用方法：

Camera.open() 创建Camera实例，打开相机
getParameters() 获取相机参数
release() 释放相机资源
setParameters(Camera.Parameters parameters) 设置相机参数
setPreviewDisplay(SurfaceHolder holder) 设置用于预览的SurfaceView
setDisplayOrientation(int i) 设置默认角度，值为度数，如值为90即90°
startPreview() 开始预览
stopPreview() 停止预览
takePicture(Camera.ShutterCallback shutter,Camera.PictureCallback raw, Camera.PictureCallback jepg) 用于拍摄，参数shutter为快门回调函数常用于音效等；参数raw为拍摄后回调提供照片数据；参数jpeg为拍摄后回调提供无损照片数据

相机参数常用方法

setPictureSize(int width,int height)  设置图片尺寸
setPictureFormat(int pixelFormat)  设置图片格式，如PixelFormat.JPEG
set("jpeg-quality",int quality)  设置图片质量，quality值标准为65，一般为75左右，不超过100
setFocusMode(String focusMode) 设置对焦模式，如FOCUS_MODE_CONTINUOUS_PICTURE为连续图片对焦

        //设置相机camera= Camera.open();Camera.Parameters parameters =camera.getParameters();parameters.setPictureSize(640*3,480*3);parameters.setPictureFormat(PixelFormat.JPEG);parameters.set("jpeg-quality",80);parameters.setFocusMode(FOCUS_MODE_CONTINUOUS_PICTURE);camera.setParameters(parameters);camera.setDisplayOrientation(90);

        //绑定SurfaceViewSurfaceHolder surfaceHolder=surfaceView.getHolder();surfaceHolder.addCallback(new SurfaceHolder.Callback() {public void surfaceCreated(@NonNull SurfaceHolder surfaceHolder) {try {camera.setPreviewDisplay(surfaceHolder);//启动预览camera.startPreview();} catch (IOException e) {throw new RuntimeException(e);}}public void surfaceChanged(@NonNull SurfaceHolder surfaceHolder, int i, int i1, int i2) {try {camera.setPreviewDisplay(surfaceHolder);//启动预览camera.startPreview();} catch (IOException e) {throw new RuntimeException(e);}}public void surfaceDestroyed(@NonNull SurfaceHolder surfaceHolder) {try {camera.setPreviewDisplay(surfaceHolder);//启动预览camera.startPreview();} catch (IOException e) {throw new RuntimeException(e);}}});//设置拍摄按钮监听器putButton.setOnClickListener(new View.OnClickListener() {public void onClick(View view) {camera.takePicture(null, null, new Camera.PictureCallback() {public void onPictureTaken(byte[] bytes, Camera camera) {camera.stopPreview();Bitmap bitmap_base=BitmapFactory.decodeByteArray(bytes,0,bytes.length);String sdPath= String.valueOf(Environment.getExternalStorageDirectory());//API29以上已不允许在SD卡目录下创建文件夹或文件，需在已有（自带）文件夹下创建文件夹或文件File file=new File(sdPath+"/DCIM/myCamera");boolean fileExists=false;if(!file.exists()){fileExists=file.mkdirs();}else {fileExists=true;}Log.d("OK","文件夹是否存在"+fileExists);int num=1;while (true){String imageName="image"+num+".jpeg";File imageFile=new File(file.getAbsolutePath()+"/"+imageName);if(!imageFile.exists()){//不存在，进行创建imageFile.getParentFile().mkdirs();try {imageFile.createNewFile();} catch (IOException e) {throw new RuntimeException(e+"地址"+imageFile.getAbsolutePath());}try {FileOutputStream outputStream = new FileOutputStream(imageFile);bitmap_base.compress(Bitmap.CompressFormat.JPEG,100,outputStream);Log.d("OK","保存完成"+imageFile.getAbsolutePath());outputStream.flush();outputStream.close();} catch (FileNotFoundException e) {throw new RuntimeException(e);} catch (IOException e) {throw new RuntimeException(e);}camera.startPreview();break;}else {num++;}}}});}});

    //要记得释放相机资源protected void onDestroy() {super.onDestroy();if(camera!=null){camera.release();}}protected void onPause() {super.onPause();camera.stopPreview();}protected void onRestart() {super.onRestart();camera.startPreview();}