小编use*_*770的帖子

我正在寻找android中camera2手动对焦的一个例子.我试图获得下面显示的最小焦距和可用焦距,但它没有帮助.如何控制焦距？

float minimumLens = characteristics.get(CameraCharacteristics.LENS_INFO_MINIMUM_FOCUS_DISTANCE);

float[] lensDistances = characteristics.get(CameraCharacteristics.LENS_INFO_AVAILABLE_FOCAL_LENGTHS); 

我需要用seekbar来控制它.提前致谢.

我正在阅读有关此的许多报告，但仍然找不到适合我的答案。有时，在使用camera2捕获后，会引发异常：java.lang.IllegalStateException：会话已关闭；进一步的更改是非法的。我尝试检查所有会话在执行某项操作时是否不为空，但仍然可以得到。有什么建议吗？我还应该处理其他什么？=，我不知道吗？

 private CameraCaptureSession.CaptureCallback mCaptureCallback
            = new CameraCaptureSession.CaptureCallback() {

        private void process(CaptureResult result) {
            switch (mState) {
                case STATE_PREVIEW: {

                    if(touchFocusEnabled) {
                        letSetCaptureSessionOnce = true;
                        mState = STATE_WAITING_LOCK;
                        try {
                            // Reset the auto-focus trigger
                            mPreviewRequestBuilder.set(CaptureRequest.CONTROL_AF_TRIGGER,
                                    CameraMetadata.CONTROL_AF_TRIGGER_CANCEL);
                            mPreviewRequestBuilder.set(CaptureRequest.CONTROL_AF_TRIGGER,
                                    CameraMetadata.CONTROL_AF_MODE_CONTINUOUS_PICTURE);

                            mCaptureSession.capture(mPreviewRequestBuilder.build(), mCaptureCallback,
                                    mHandler);
                        } catch (CameraAccessException e) {
                            L.e("CameraLolipop --- CameraCaptureSession.CaptureCallback " + e);
                        }
                    } else {
                        if(letSetCaptureSessionOnce) {
                            try {
                                if ((null != mCaptureSession) && (isCameraOpen)) {
                                    mState = STATE_PREVIEW;
                                    mCaptureSession.capture(mPreviewRequestBuilder.build(), mCaptureCallback,
                                            mHandler);
                                    letSetCaptureSessionOnce = true;
                                }

                            } catch (CameraAccessException …