java - Camera2 - 更改 fragment 时为 "Must be called from main thread of fragment host"

Question

我试图使用以下代码在拍摄图像后更改 fragment Google Sample - Camera2Basic 。

我在上述示例的第 839 行实现了对 MainActivity 的回调。但是，当我尝试从该回调遍历到不同的 Activity 时，我收到以下异常:

java.lang.IllegalStateException: Must be called from main thread of fragment host

有人知道这件事吗？

Answer 1

我有 Kotlin 中的工作代码您必须将此回调替换为:

  val captureCallback = object : CameraCaptureSession.CaptureCallback() {

            override fun onCaptureCompleted(session: CameraCaptureSession,
                                            request: CaptureRequest,
                                            result: TotalCaptureResult) {
                sendBackResult(mFile)
            }
        }

        mCaptureSession!!.capture(captureBuilder.build(), captureCallback, mBackgroundHandler)
    } catch (e: CameraAccessException) {
        e.printStackTrace()
    }

sendBackResult方法如下:

private fun sendBackResult(resultFile: File?) {
    val fileUri = Uri.fromFile(resultFile)
    val dataIntent = Intent()
    dataIntent.data = fileUri
    dataIntent.putExtra("isFront", isFrontCamera)
    activity!!.setResult(Activity.RESULT_OK, dataIntent)
    activity!!.finish()
}