android - 使用 Android Camera2，应用会无限期地卡在 STATE_WAITING_PRECAPTURE 或 STATE_WAITING_NON_PRECAPTURE

Question

我正在使用 Android Camera2 API .我想知道什么时候是合适的时间:

1. 最初显示TakePicture 按钮(即相机已准备好拍摄一张照片)。
2. 再次显示此按钮(如果拍照过程失败，当然还有完成时)，因为我在单击它(拍摄照片)时将其隐藏。

我在 lockFocus() 中尝试了 takePicture.setVisibility(View.GONE) ，在 中尝试了 takePicture.setVisibility(View.VISIBLE) >解锁焦点()。虽然这在大多数情况下都有效，但有时按钮会消失并且再也不会出现(我猜是在拍照过程失败时)，尤其是在非常快速地单击它时(只要它出现在屏幕上)。此时没有错误，也没有发生崩溃。

代码取自googlesamples/android-Camera2Basic .

更新:

我在 onCaptureSequenceCompleted 中尝试了 takePicture.setVisibility(View.VISIBLE)。该按钮确实出现，但在单击它时不会重新启动捕获图片的过程(参见 this seven-second video )。发生这种情况时，不会调用 onCaptureFailed。但是，它会无限期地卡在 STATE_WAITING_PRECAPTURE 或 STATE_WAITING_NON_PRECAPTURE 因为 aeState 这不会'满足if条件。

           case STATE_WAITING_PRECAPTURE: {
                // CONTROL_AE_STATE can be null on some devices
                Integer aeState = result.get(CaptureResult.CONTROL_AE_STATE);
                if (aeState == null ||
                        aeState == CaptureResult.CONTROL_AE_STATE_PRECAPTURE ||
                        aeState == CaptureRequest.CONTROL_AE_STATE_FLASH_REQUIRED) {
                    mState = STATE_WAITING_NON_PRECAPTURE;
                }
                break;
            }
            case STATE_WAITING_NON_PRECAPTURE: {
                // CONTROL_AE_STATE can be null on some devices
                Integer aeState = result.get(CaptureResult.CONTROL_AE_STATE);
                if (aeState == null || aeState != CaptureResult.CONTROL_AE_STATE_PRECAPTURE) {
                    mState = STATE_PICTURE_TAKEN;
                    captureStillPicture();
                }
                break;
            }

Answer 1

我觉得应该是这样的

 case STATE_WAITING_PRECAPTURE:
              {
                JQLog.d(TAG, "STATE_WAITING_PRECAPTURE");
                // CONTROL_AE_STATE can be null on some devices
                Integer aeState = result.get(CaptureResult.CONTROL_AE_STATE);
                if (aeState == null
                    || aeState == CaptureResult.CONTROL_AE_STATE_PRECAPTURE
                    || aeState == CaptureRequest.CONTROL_AE_STATE_FLASH_REQUIRED
                    || aeState == CaptureResult.CONTROL_AE_STATE_CONVERGED) {
                  state = STATE_WAITING_NON_PRECAPTURE;
                }
                break;
              }