我想在Android WebView的PWA中使用QR码扫描仪。

PWA在chrome浏览器上可以正常工作。

我确实有在“应用程序”->“应用程序名称”->“权限”下设置摄像机的权限

minSdkVersion 26和targetSdkVersion 28

在装有Android 9的华为手机上测试

问题是似乎没有授予该权限。 另外，许可请求被重复多次。

Android代码

表现

android:name="android.hardware.camera"

android:required="true" />

根据上一个问题的答案，我在WebViewHelper类中有此代码

lateinit var webkitPermissionRequest : PermissionRequest

...

webView.webChromeClient = object : WebChromeClient() {

override fun onPermissionRequest(request: PermissionRequest) {

webkitPermissionRequest = request

val requestedResources = request.resources

for (r in requestedResources) {

if (r == PermissionRequest.RESOURCE_VIDEO_CAPTURE) {

// In this sample, we only accept video capture request.

val alertDialogBuilder = AlertDialog.Builder(activity)

.setTitle("Allow Permission to camera")

.setPositiveButton("Allow") { dialog, which ->

dialog.dismiss()

webkitPermissionRequest.grant(arrayOf(PermissionRequest.RESOURCE_VIDEO_CAPTURE))

Log.d(TAG, "Granted")

}

.setNegativeButton("Deny") { dialog, which ->

dialog.dismiss()

webkitPermissionRequest.deny()

Log.d(TAG, "Denied")

}

val alertDialog = alertDialogBuilder.create()

alertDialog.show()

break

}

}

}

...

}

日志：授予权限后，将再次请求(多次)

D/WebViewHelper: Granted

V/InputMethodManager: Reporting focus gain, without startInput

I/PermissionManager: camera remind result:true

I/CameraManager: open camera: 1, package name: "myApp"

I/BackgroundPermManager: pkgName: "myApp", pid: 31365 ,uidOf3RdApk: 10197 ,permType: 0 ,permCfg: 1

I/HwCameraUtil: notifySurfaceFlingerCameraStatus : isFront = true , isOpend = true

I/HwCameraUtil: notifySurfaceFlingerFrontCameraStatus 8011 transact success!

E/cr_VideoCapture: CameraDevice.StateCallback onOpened

I/WebViewHelper: onPermissionRequest

onPermissionRequest

这似乎是问题所在

I/GRALLOC: LockFlexLayout: baseFormat: 11, yStride: 640, ySize: 307200, uOffset: 307200, uStride: 640

E/ion: ioctl c0044901 failed with code -1: Invalid argument

I/chromium: "Unhandled rejection", source: "PWA

"Uncaught (in promise) NotAllowedError: play() can only be initiated by a user gesture.", source: "PWA"

最后，此错误重复出现(无限期)

I/GRALLOC: LockFlexLayout: baseFormat: 11, yStride: 640, ySize: 307200, uOffset: 307200, uStride: 640

JavaScript代码

JS端的代码可以很好地工作，直到在WebView中打开为止。

app.ports.scanQR.subscribe(() => {

// Delay until page loaded

setTimeout(function(){

const video = document.getElementById('media-video');

function returnResult(result) {

app.ports.onGotQR.send(result);

scanner.destroy();

}

const scanner = new QrScanner(video, result => returnResult(result));

scanner.start();

}, 50);

});

}

如果我直接致电getUserMedia，问题仍然存在

if (navigator.mediaDevices.getUserMedia) {

navigator.mediaDevices.getUserMedia({ video: true })

.then(function (stream) {

video.srcObject = stream;

})

.catch(function (err0r) {

console.log("Something went wrong!");

});

}

取得相机的「应用程式」权限：

在WebviewHelper.kt中

webView.webChromeClient = object : WebChromeClient() {

override fun onPermissionRequest(request: PermissionRequest) {

Log.i(TAG, "onPermissionRequest")

// grants permission for app. video not showing

if (ContextCompat.checkSelfPermission(activity, Manifest.permission.CAMERA)

!= PackageManager.PERMISSION_GRANTED

) {

Log.i(TAG, "Request Permission")

requestPermissions(activity, arrayOf(Manifest.permission.CAMERA), 1010)

} else {

Log.i(TAG, "Permission already granted")

}

...

}

在MainActivity.kt中

override fun onRequestPermissionsResult(requestCode: Int, permissions: Array, grantResults: IntArray) {

when (requestCode) {

cameraRequestCode -> {

Log.d("MainActivity", "onRequestPermissionsResult: Camera Request")

if ((grantResults.isNotEmpty() && grantResults[0] == PackageManager.PERMISSION_GRANTED)) {

Log.d("MainActivity", "Camera Request: Permission granted")

// permission was granted, yay!

} else {

// permission denied, boo!

Log.d("MainActivity", "Camera Request: Permission denied")

}

return

}

...

授予相机的“应用程序”权限后，将按预期结果显示以下日志：

D/MainActivity: onRequestPermissionsResult: Camera Request

Camera Request: Permission granted