闪光灯开/关相机 2 api Android

Question

我正在开发一个相机应用程序，我使用以下代码制作闪光灯，

private void setFlashMode(CaptureRequest.Builder builder) {
    switch (preferences.getInt("Flashmode", 0)) {
        case 1:
            builder.set(CaptureRequest.CONTROL_AE_MODE, CaptureRequest.CONTROL_AE_MODE_ON_ALWAYS_FLASH);
            builder.set(CaptureRequest.FLASH_MODE, CameraMetadata.FLASH_MODE_OFF);
            break;

        case 0:
            builder.set(CaptureRequest.CONTROL_AE_MODE, CaptureRequest.CONTROL_AE_MODE_ON);
            builder.set(CaptureRequest.FLASH_MODE, CameraMetadata.FLASH_MODE_OFF);
            break;

        case 2:
            builder.set(CaptureRequest.CONTROL_AE_MODE, CameraMetadata.CONTROL_AE_MODE_ON_AUTO_FLASH);
            builder.set(CaptureRequest.FLASH_MODE, CameraMetadata.FLASH_MODE_OFF);
            break;
        case 3:
            builder.set(CaptureRequest.CONTROL_AE_MODE, CaptureRequest.CONTROL_AE_MODE_ON);
            builder.set(CaptureRequest.FLASH_MODE, CaptureRequest.FLASH_MODE_TORCH);
    }
}

我参考了许多帖子并尝试了所有帖子。但我找不到解决方案。这就是为什么即使已经有人问过我也要发布它。

问题是，只有 Flash 模式不起作用

当我点击拍摄按钮时，闪光灯持续闪烁。