surfaceview

SurfaceView 的优点 使用双缓冲技术 自带画布，支持在子线程中更新画布内容 View 和 SurfaceView 各自使用场景 界面需要被动更新：使用View 。 画面更新是依赖于onTouch 来完成的，所以可以直接使用 invalidate() 函数。这种情况下，两次onTouch()间隔时间较长，不会产生影响 界面需要主动更新：使用SurfaceView。如一个动画需要一直移动或变化，这时需要一个单独的线程不停绘制人的状态，避免阻塞主线程。 界面需要频繁刷新，或刷新时数据处理量较大：使用SurfaceView。如视频播放、camera SurfaceView继承于View，因此SurfaceView 可使用View中的所有方法，但：：由于View中所有方法在主线程完成，当SurfaceView重写View的方法，那么也在主线程中完成。 总结： 原本能通过派生自View实现的控件，依然可以通过SurfaceView 实现，因为SurfaceView派生自View 当SurfaceView需要使用View的onDraw（）来重绘控件时，需要在初始化的时候调用setWillNotDraw(false)【surfaceview默认为true，也就是不推荐这样】，否则onDraw（）函数不会被调用 View中的所有方法都在主线程中执行

I have subclassed the SurfaceView and instantiating it in onCreate of the Activity. The preview is generated but the control never enters onDraw() which is overriden in the subclass of SurfaceView. Why is that? class ActivityClass extends Activity{ onCreate(){ mPreview = new Preview(this); setContentView(mPreview); } public void startPreview(){ rec = new MediaRecorder(); rec.setVideoSource();....... rec.setPreviewDisplay(mPreview.getSurfaceHolder.getSurface()); } } class Preview extends SurfaceView implements SurfaceHolder.Callback{ SurfaceHolder mHolder; public Preview(Context context){ super

I am creating a Barcode Scanner app and I want to use Zxing to read barcodes, my app has a surfaceview and showing camera into that, but now I want to scan barcode from my SurfaceView camera , the reason that I use it, is that I have two Edittexts under the surface view in my layout to show content of barcode. How should I create an app like, the main problem is that how can I set zxing into surface. If there's any way I would appreciate. Layout screenshot: Customize your zxing layout with below codes. I took here a RelativeLayout for zxing Scanner. Or, Go with this references : https://github

In simple words, all I need to do is display a live stream of video frames in Android (each frame is YUV420 format). I have a callback function where I receieve individual frames as a byte array. Something that looks like this : public void onFrameReceived(byte[] frame, int height, int width, int format) { // display this frame to surfaceview/textureview. } A feasible but slow option is to convert the byte array to a Bitmap and draw to canvas on SurfaceView. In the future, I would ideally like to be able to alter brightness, contrast etc of this frame, and hence am hoping I can use OpenGL-ES

I have created a custom camera preview view CameraView which extends SurfaceView , and it also implements SurfaceHolder.Callback interface. The view operates with the camera. When you open the view it shows a camera preview. On the same screen there is also overlay with two buttons - 'Take picture', 'Choose from gallery'. The activity that holds the CameraView releases and reopens the camera in onPause() and onResume() methods. If I click the 'Choose from gallery' button, the following intent is created: Intent intent = new Intent(Intent.ACTION_GET_CONTENT); intent.setType("image/*");

I have a Tab Activity with 2 tabs (activities). Each tab has a 3d Open GL scene drawn on top of a SurfaceView with camera preview. Yet, depending on device orientation, tabs are being switched. The problem is that when the other activity starts, it calls camera.open(), which generates exception, saying that camera service is unavailable. In fact, the problem is that camera is not stopped when activity is paused, in other words onSurfaceDestroyed() is not called for the SurfaceView. I tried to stop camera when onPause() for activities is called, but get the same error still. Anyone had same

I have a quick question. I'm using Android's SurfaceView to take a picture and save it. However, the preview size and the picture quality itself is both terrible; as in, it is very blurry. There's no sharpness to the picture quality at all. Here's where I initialize my surfaceView: camera.setDisplayOrientation(90); Parameters parameters = camera.getParameters(); parameters.setWhiteBalance(Camera.Parameters.WHITE_BALANCE_AUTO); parameters.setExposureCompensation(0); parameters.setPictureFormat(ImageFormat.JPEG); parameters.setJpegQuality(100); Camera.Size picSize = getOptimalPreviewSize