<?xml version="1.0" encoding="utf-8"?>

      
  
    
    
  

public class TakephotoActivity extends AppCompatActivity {

  private SurfaceView sv_takephoto;
  private Button b_OK;
  private Button b_qh;
  private Camera camera;

  @Override
  protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.activity_takephoto);
    //获得SurfaceView的ID
    sv_takephoto =(SurfaceView) findViewById(R.id.sv_takephoto);
    //获得拍照的ID
    b_OK =(Button)findViewById(R.id.b_OK);
    //获得切换镜头的ID
    b_qh =(Button)findViewById(R.id.b_qh);

    sv_takephoto.getHolder().addCallback(new SurfaceHolder.Callback() {
      @Override
      public void surfaceCreated(SurfaceHolder surfaceHolder) {
      //打开相机
        camera = Camera.open();
        //给相机设置参数
        Camera.Parameters parameters= camera.getParameters();
        //设置保存的格式
        parameters.setPictureFormat(PixelFormat.JPEG);
        parameters.set("jpeg-quality",85);
        camera.setParameters(parameters);

        //将画面展示到SurfaceView中
        try {
          camera.setPreviewDisplay(sv_takephoto.getHolder());
          //开启预览
          camera.startPreview();
        } catch (IOException e) {
          e.printStackTrace();
        }

      }

      @Override
      public void surfaceChanged(SurfaceHolder surfaceHolder, int i, int i1, int i2) {

      }

      @Override
      public void surfaceDestroyed(SurfaceHolder surfaceHolder) {

      }
    });

    //拍照的点击事件
    b_OK.setOnClickListener(new View.OnClickListener() {
      @Override
      public void onClick(View view) {
        //拍照
        camera.takePicture(null, null, new Camera.PictureCallback() {
          @Override
          public void onPictureTaken(byte[] bytes, Camera camera) {
            //将字节数组转成图片
            Bitmap bitmap= BitmapFactory.decodeByteArray(bytes,0,bytes.length);
            try {
              FileOutputStream fos=new FileOutputStream("/mnt/sdcard/DCIM/"+System.currentTimeMillis()+".jpg");
              bitmap.compress(Bitmap.CompressFormat.PNG,85,fos);
              camera.stopPreview();
              camera.startPreview();
            } catch (FileNotFoundException e) {
              e.printStackTrace();
            }
          }
        });

    }
    });

  }
}