Question

您好我正在使用SurfaceView开发具有相机功能的应用程序。我想在创建表面视图时拍照。

在我的片段onCreateView方法中，初始化了我需要的所有内容。

@Override
    public View onCreateView(LayoutInflater inflater, ViewGroup container,
                             Bundle savedInstanceState) {
        // Inflate the layout for this fragment
        view = inflater.inflate(R.layout.game_one_start_fragment, container, false);

        initWidgets(view);    
        return view;

    }

在initWidgets（）方法中初始化SurfaceView对象，如下所示

mSurfaceView = (SurfaceView) view.findViewById(R.id.game_action_surfaceview);
mSurfaceHolder = mSurfaceView.getHolder();

在OnResume（）方法中获取surfaceHolder对象。

@Override
    public void onResume() {
        super.onResume();
        mSurfaceHolder.addCallback(this);
        mSurfaceHolder.setType(SurfaceHolder.SURFACE_TYPE_PUSH_BUFFERS);
        safeCameraOpen(Camera.CameraInfo.CAMERA_FACING_BACK);

    }

safeCameraOpen（）我已关注Android Developer link。使用与上述相同的代码。

surfaceHolder.callback使用如下

@Override
    public void surfaceCreated(SurfaceHolder holder) {

        mCamera.startPreview();

    }


    @Override
    public void surfaceChanged(SurfaceHolder holder, int format, int width, int height) {

        try {
//to set the picture orientation
            setCameraDisplayOrientation(getActivity(), findFrontFacingCameraID(), mCamera);
            mCamera.startPreview();
            mCamera.setPreviewDisplay(holder);

        } catch (IOException e) {

            e.printStackTrace();

        }

        Camera.Parameters parameters = mCamera.getParameters();
        parameters.getSupportedPreviewSizes();

        mCamera.setParameters(parameters);


    }

    @Override
    public void surfaceDestroyed(SurfaceHolder holder) {
        mCamera.stopPreview();
        mCamera.release();
    }

我想在加载片段时拍照。

我尝试过OnViewCreated（），onResume（）和onStart（）生命周期方法。在其中我使用了以下行

 mCamera.takePicture(null,null,mPictureCallback);

（在safeCameraOpen（）方法中创建和初始化的mCamera对象）

如果我在提到的生命周期方法中尝试，我会收到以下崩溃错误。

java.lang.RuntimeException: takePicture failed
            at android.hardware.Camera.native_takePicture(Native Method)
            at android.hardware.Camera.takePicture(Camera.java:1266)
            at android.hardware.Camera.takePicture(Camera.java:1211)
            at com.gaming.fragment.GameOneStartFragment.snapPicture(GameOneStartFragment.java:76)
            at com.gaming.fragment.GameOneStartFragment.surfaceCreated(GameOneStartFragment.java:284)
            at android.view.SurfaceView.updateWindow(SurfaceView.java:572)
            at android.view.SurfaceView.access$000(SurfaceView.java:86)
            at android.view.SurfaceView$3.onPreDraw(SurfaceView.java:175)
            at android.view.ViewTreeObserver.dispatchOnPreDraw(ViewTreeObserver.java:847)
            at android.view.ViewRootImpl.performTraversals(ViewRootImpl.java:1897)
            at android.view.ViewRootImpl.doTraversal(ViewRootImpl.java:1019)
            at android.view.ViewRootImpl$TraversalRunnable.run(ViewRootImpl.java:5725)
            at android.view.Choreographer$CallbackRecord.run(Choreographer.java:761)
            at android.view.Choreographer.doCallbacks(Choreographer.java:574)
            at android.view.Choreographer.doFrame(Choreographer.java:544)
            at android.view.Choreographer$FrameDisplayEventReceiver.run(Choreographer.java:747)
            at android.os.Handler.handleCallback(Handler.java:733)
            at android.os.Handler.dispatchMessage(Handler.java:95)
            at android.os.Looper.loop(Looper.java:136)
            at android.app.ActivityThread.main(ActivityThread.java:5086)
            at java.lang.reflect.Method.invokeNative(Native Method)
            at java.lang.reflect.Method.invoke(Method.java:515)
            at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:785)
            at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:601)
            at dalvik.system.NativeStart.main(Native Method)

但是，当我在按钮内使用Camera对象的takePicture（）方法时，单击它会捕获图片。

如何在没有点击查看的情况下拍照？

Answer 1

您不会调用Camera对象的startPreview方法。我想你应该在拍照前打电话给startPreview。在这种情况下，您没有设置预览显示：

try {
   camera.setPreviewDisplay(surface.getHolder());
} catch (IOException e) {
   // TODO Auto-generated catch block
   e.printStackTrace();
}

检查此答案：How to take pictures from the camera without preview when my app starts?

在Android

1 个答案: