问题
This time I need your help regarding the use of android navigation components with deeplink.
I have been following this documentation and the connection between fragment and deeplink is working fine.
The problem comes in regards to the activity that is receiving the deeplink. In my case, I set the android:launchMode="singleTask"
<activity android:name=".features.welcome.WelcomeActivity"
android:launchMode="singleTask">
<nav-graph android:value="@navigation/welcome_nav_graph" />
</activity>
override fun onNewIntent(intent: Intent?) {
super.onNewIntent(intent)
Timber.d("onNewIntent: $intent with activity: $this")
navController.handleDeepLink(intent)
}
With this configuration I noticed a couple of weird behaviours:
WelcomeActivity receives onNewIntent call two times every time I click the deeplink. Having even sometimes new instances of that activity created.. like
1_ object1-onNewIntent
2_ object1-onNewIntent
3_ object2-onCreate
Here you have some logs:
First launch
onCreate: Intent { flg=0x10000000 cmp={applicationId}/{package}.WelcomeActivity } with activity: {package}.WelcomeActivity@4adbef0
Open deep link
onNewIntent: Intent { act=android.intent.action.VIEW cat=[android.intent.category.BROWSABLE] dat=https://{depp_link}… flg=0x10010000 cmp={applicationId}/{package}.WelcomeActivity (has extras) } with activity: {package}.WelcomeActivity@4adbef0
onNewIntent: Intent { act=android.intent.action.VIEW cat=[android.intent.category.BROWSABLE] dat=https://{depp_link}... flg=0x1001c000 cmp={applicationId}/{package}.WelcomeActivity (has extras) } with activity: {package}.WelcomeActivity@4adbef0
onCreate: Intent { act=android.intent.action.VIEW cat=[android.intent.category.BROWSABLE] dat=https://{depp_link}... flg=0x1001c000 cmp={applicationId}/{package}.WelcomeActivity (has extras) } with activity: {package}.WelcomeActivity@b77c6b
Kill the app and open deep link
onCreate: Intent { act=android.intent.action.VIEW cat=[android.intent.category.BROWSABLE] dat=https://{depp_link}... flg=0x10018000 cmp={applicationId}/{package}.WelcomeActivity (has extras) } with activity: {package}.WelcomeActivity@b78f4df
onNewIntent: Intent { act=android.intent.action.VIEW cat=[android.intent.category.BROWSABLE] dat=https://{depp_link}... flg=0x1001c000 cmp={applicationId}/{package}.WelcomeActivity (has extras) } with activity: {package}.WelcomeActivity@b78f4df
onCreate: Intent { act=android.intent.action.VIEW cat=[android.intent.category.BROWSABLE] dat=https://{depp_link}... flg=0x1001c000 cmp={applicationId}/{package}.WelcomeActivity (has extras) } with {package}.WelcomeActivity@dfe87b2
UPDATE:
1 -It seems launch mode has nothing to with this issue. I noticed the same with default launch mode.
2- navController.navigate(intent.dataString.toUri()) seems to work fine. So I guess the problem is navController.handleDeepLink(intent).
回答1:
Testing different changes, I came to the conclusion that "navController.handleDeepLink(intent)" is causing this weird behaviour.
This is what I tried:
I removed the deepLink from the navigation, and the deep link was working just fine (I have added deepLink manually) with a normal behaviour: using singleTask, if the activity is already created, then onNewIntent is called only once. If the activity is not created, then onCreate is called.
An extra problem with this is that navController.handleDeepLink(intent) will be called automatically in onCreate (you can check that in the javadocs). When onNewIntent is called, you need to call navController.handleDeepLink(intent).
I decided to try "navigate(Uri deepLink)" from NavController and I see that is working as expected (behaviour described in the first paragraph). Having this alternative method, I decided to make some changes:
class WelcomeActivity : AppCompatActivity(){
private val navController by lazy { findNavController(R.id.nav_host_fragment) }
private var deepLinkData: Uri? = null
override fun onCreate(savedInstanceState: Bundle?) {
super.onCreate(savedInstanceState)
Timber.d("onCreate: $intent with activity: $this")
val data = intent.data
intent.data = null
setContentView(R.layout.activity_welcome)
handleDeepLink(data)
}
override fun onNewIntent(intent: Intent?) {
super.onNewIntent(intent)
Timber.d("onNewIntent: $intent with activity: $this")
setIntent(intent)
val data = intent?.data
handleDeepLink(data)
}
private fun handleDeepLink(uri: Uri?) {
//TODO: there is an issue that will cause onNewIntent to be called twice when the activity is already present.
if (uri != null && deepLinkData.toString() != uri.toString() && navController.graph.hasDeepLink(uri)) {
//possible deep link for LoginOTPFragment
deepLinkData = uri
navController.navigate(uri)
}
}
}
It is important to notice this block of code in onCreate:
val data = intent.data
intent.data = null
The reason for this is because if I need to prevent "navController.handleDeepLink(intent)" to be called as it will be called automatically if that information is present, causing the weird behaviour.
navController.graph.hasDeepLink(uri) will help you to see if you graph can handle that uri. If you do not use it, then "navigate(Uri deepLink)" will throw an exception.
Hope it can help you if you are running into the same problem. If you have more insights on this, feel free to leave some comments.
回答2:
It feels weird, but it actually seems to work as intended. The documentation regarding the implicit deep links says:
When triggering an implicit deep link, the state of the back stack depends on whether the implicit Intent was launched with the Intent.FLAG_ACTIVITY_NEW_TASK flag:
If the flag is set, the task back stack is cleared and replaced with the deep link destination....
If the flag is not set, you remain on the task stack of the previous app where the implicit deep link was triggered.
In your case I believe when you tap a link the intent has the flag Intent.FLAG_ACTIVITY_NEW_TASK set, so the whole new stack is created. Currently the implementation just restarts the activity with the newly created stack to make sure the task state is consistent.
If you don't need this behavior, one possible workaround would be to clear the flag Intent.FLAG_ACTIVITY_NEW_TASK from the intent before navigation component has a chance to handle it.
来源：https://stackoverflow.com/questions/61951850/android-navigation-components-with-deep-link-onnewintent-called-multiple-times