Android - URI Scheme - Stop from opening multiple instances of application -

-

i'm using custom uri scheme redirect user website application, when launching app, opens new instance instead of restoring open one.

i have tried both using launchmode="singletask" or "singleinstance" don't seem affect it. 

<!-- splash. -->     <activity         android:launchmode="singletask"          android:name=".activities.splash"         android:label="@string/app_name"         android:screenorientation="portrait"         android:windowsoftinputmode="statehidden"         >          <intent-filter>             <data android:scheme="customscheme" />             <action android:name="android.intent.action.view"/>             <category android:name="android.intent.category.browsable" />             <category android:name="android.intent.category.default"/>         </intent-filter>          <intent-filter>             <action android:name="android.intent.action.main"/>             <category android:name="android.intent.category.launcher"/>         </intent-filter>       </activity>

example:

  1. user opens application, activity goes activity b .

  2. user opens website, , gets redirected app via uri.

  3. application on activity a.

  4. user presses button, destroying activity a.

  5. activity b present first instance.

thanks time , help!

assuming you've not set android:taskaffinity activity b, doing correct thing.

  • when launch app starts activitya
  • activitya launches activityb same task (even if set launchmode="singleinstance" activityb, android ignore since has same taskaffinity activitya)
  • user opens website , redirected app. android brings existing task application (containing activitya , activityb) foreground , creates new instance of activitya , puts on top of existing activies. have task stack activitya -> activityb -> activitya.
  • user presses button, finishes instance of activitya on top of stack , reveals instance of activityb underneath.

if think this, android cannot open existing instance of activitya because covered activityb.

there multiple ways of getting around this, depending on how want app behave in different circumstances. let's assume that, if app running, want task stack cleared root instance of activitya , want reuse instance (and not create one). 1 of easiest ways have web browser open activity (not activitya), let's call redirectactivity . new activity has following code in oncreate():

super.oncreate(...); intent intent = new intent(this, activitya.class); intent.addflags(intent.flag_activity_clear_top | intent.flag_activity_single_top); startactivity(intent); finish();

this code 1 of following, depending...

  1. if app not running, create new instance of activitya.
  2. if app running, clear task stack of activities may on top of existing instance of activitya , return existing instance of activitya.

note: there other behaviours might appropriate , other techniques can use similar behaviour.


Comments

Post a Comment

Popular posts from this blog

python - No exponential form of the z-axis in matplotlib-3D-plots -

-
Image
i have similar problem described in how prevent numbers being changed exponential form in python matplotlib figure : i don't want (in special case) weird scientific formatting of axis. problem different have problem @ z -axis. 2-d plots can use ax.get_yaxis().get_major_formatter().set_useoffset(false) . , there no function ax.get_zaxis() what use format z -axis same way? edit: example: from mpl_toolkits.mplot3d import axes3d import numpy np import sys import matplotlib import matplotlib.pyplot pyplot def func(xi, ti): res = 10e3 + np.cos(ti) * np.sin(xi) return res if __name__ == '__main__': timespacing = 20 timestart = 0 timeend = 1 time = np.linspace(timestart, timeend, timespacing) widthspacing = 50 widthstart = 0 widthend = 3 width = np.linspace(widthstart, widthend, widthspacing) reslist = [] matplotlib.rcparams['legend.fontsize'] = 10 fig = pyplot.figure() ax = fig.gca(projection = '3d...
Read more

php - Best Light server (Linux + Web server + Database) for Raspberry Pi -

-
i install web server database on raspberry pi (little computer). computer has 1gb ram. i want know best combination: linux distribution , web server , dbms run local server multiple users minimal latency, use php on server. , best settings performance , not have bugs (memory usage, disable plugin, disable service, etc)? i thought light debian , lighttpd server , sqlite database. solution? i think lighttpd + sqlite great choice. linux distro, debian @ centos or tiny core linux , although i'm not sure of compatibility pi. obviously, can't go wrong raspbian if want use in production , more stable performance, few more pi's , set them in cluster .
Read more

c# - "Newtonsoft.Json.JsonSerializationException unable to find constructor to use for types" error when deserializing class -

-
i developing app in xamarin android. have splash screen serialize class , pass mainactivity using intent . when try deserialize in mainactivity error message : "serializationexception unable find constructor use types" serialization : void loaddata() { currency currency = new currency(this); intent = new intent(this, typeof(mainactivity)); intent.putextra("currency", newtonsoft.json.jsonconvert.serializeobject(currency)); startactivity(intent); } deserialization : cur = newtonsoft.json.jsonconvert.deserializeobject<currency> (intent.getstringextra("currency")); // error here class constructor : public currency(context context) { thiscontext = context; } i began experiencing problem after added parameter context context constructor. has caused this? how can solve it? possible serialize/deserialize class has parameters? you need have empty constructor in currency class in order deserialize it. ...
Read more