android - Kotlin - Unresolved 常量引用

Question

我正在尝试为我的 Android 应用程序使用新相机硬件 API (android.hardware.camera2) 的示例代码。首先，我通过 Android Studio 的 Kotlin 插件的自动转换功能将 Java 代码转换为 Kotlin 代码。下面是一段转换后的代码:

private val mCaptureCallback = object : CameraCaptureSession.CaptureCallback() {

    private fun process(result: CaptureResult) {
        when (mState) {
            STATE_PREVIEW -> {
            }// We have nothing to do when the camera preview is working normally.
            STATE_WAITING_LOCK -> {
                val afState = result.get(CaptureResult.CONTROL_AF_STATE)
                if (CaptureResult.CONTROL_AF_STATE_FOCUSED_LOCKED == afState || CaptureResult.CONTROL_AF_STATE_NOT_FOCUSED_LOCKED == afState) {
                    // CONTROL_AE_STATE can be null on some devices
                    val aeState = result.get<Int>(CaptureResult.CONTROL_AE_STATE)
                    if (aeState == null || aeState == CaptureResult.CONTROL_AE_STATE_CONVERGED) {
                        mState = STATE_WAITING_NON_PRECAPTURE
                        captureStillPicture()
                    } else {
                        runPrecaptureSequence()
                    }
                }
            }
            STATE_WAITING_PRECAPTURE -> {
                // CONTROL_AE_STATE can be null on some devices
                val aeState = result.get<Int>(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
                }
            }
            STATE_WAITING_NON_PRECAPTURE -> {
                // CONTROL_AE_STATE can be null on some devices
                val aeState = result.get<Int>(CaptureResult.CONTROL_AE_STATE)
                if (aeState == null || aeState != CaptureResult.CONTROL_AE_STATE_PRECAPTURE) {
                    mState = STATE_PICTURE_TAKEN
                    captureStillPicture()
                }
            }
        }
    }

我收到 Unresolved 引用错误:

CaptureResult.CONTROL_AF_STATE_FOCUSED_LOCKED
CaptureResult.CONTROL_AF_STATE_NOT_FOCUSED_LOCKED
CaptureResult.CONTROL_AE_STATE_CONVERGED
CaptureResult.CONTROL_AE_STATE_PRECAPTURE
CaptureRequest.CONTROL_AE_STATE_FLASH_REQUIRED

但是这些常量在原始Java代码中是可以识别的。这些错误有什么解决方案吗？

Answer 1

这些变量在 CameraMetadata 中声明。在 Kotlin 中，静态变量和方法不能在子类上调用。