Android - 无需预览即可拍照

Question

我正在尝试在没有预览的情况下拍照，当我的应用程序开始运行时立即拍照，然后将照片保存在根文件夹中的新文件夹 - “pictures123”中。有人可以告诉我我的代码有什么问题吗？

@Override
protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.activity_main);
    File directory = new File(Environment.getExternalStorageDirectory() + "/pictures123/");

    if (!directory.exists()) {
        directory.mkdir();
    }

    Camera camera = Camera.open(0);
    Camera.Parameters parameters = camera.getParameters();
    parameters.setPictureFormat(ImageFormat.JPEG);
    camera.setParameters(parameters);
    SurfaceView mview = new SurfaceView(getBaseContext());
    camera.setPreviewDisplay(mview.getHolder());
    camera.setPreviewDisplay(null);
    camera.startPreview();
    camera.takePicture(null,null,photoCallback);
    camera.stopPreview();
}

Camera.PictureCallback photoCallback=new Camera.PictureCallback() {
    public void onPictureTaken(byte[] data, Camera camera) {

        try {
            String root = Environment.getExternalStorageDirectory().toString();
            File myDir = new File(root + "/pictures123");
            File file = new File (myDir, "pic1.jpeg");
            FileOutputStream out = new FileOutputStream(file);
            out.write(data);
            out.flush();
            out.close();
        } catch (FileNotFoundException e) {
            e.printStackTrace();

        } catch (IOException e) {
            e.printStackTrace();

        } catch (Exception e)
        {
            e.printStackTrace();
        }
        finish();

    }
};

权限:

<uses-permission android:name="android.permission.WRITE_EXTERNAL_STORAGE"/>
<uses-permission android:name="android.permission.READ_EXTERNAL_STORAGE"/>
<uses-permission android:name="android.permission.CAMERA" />
<uses-feature android:name="android.hardware.camera" />

Answer 1

您不能在没有预览的情况下拍照，但您不必在屏幕上显示预览。您可以将输出定向到 SurfaceTexture(API 11+)。

参见 this answer了解更多详情。