Android calls a third-party App

Android calls a third-party App

1. Private List > List = null;
2. Private PackageManager mPackageManager;
3. Private List MAllApps;
4. Private Context mContext;
5.  
6. /**
7. * Check the system application and open
8. */
9. Private void openApp (){
10. // Application filtering Conditions
11. Intent mainIntent = new Intent (Intent. ACTION_MAIN, null );
12. MainIntent. addCategory (Intent. CATEGORY_LAUNCHER );
13. MPackageManager = mContext. getPackageManager ();
14. MAllApps = mPackageManager. queryIntentActivities (mainIntent, 0 );
15. // Sort by registration
16. Collections. sort (mAllApps, new ResolveInfo. DisplayNameComparator (mPackageManager ));
17.  
18. For (ResolveInfo res: mAllApps ){
19. // The package name and main Activity of the application
20. String pkg = res. activityInfo. packageName;
21. String cls = res. activityInfo. name;
22.  
23. // Open QQ
24. If (pkg. contains (qq )){
25. ComponentName componet = new ComponentName (pkg, cls );
26. Intent intent = new Intent ();
27. Intent. setComponent (componet );
28. Intent. addFlags (Intent. FLAG_ACTIVITY_NEW_TASK );
29. MContext. startActivity (intent );
30. }
31. }
32. }
33. 
    

    Many people encounter the following exceptions when using startActivity:

    Caused by: android. util. AndroidRuntimeException: Calling startActivity () from outside of an Activity context requires the FLAG_ACTIVITY_NEW_TASK flag. Is this really what you want?

     

    I once met, but after studying it, I understood the principle and wrote it down. I thought I was confused by the same troubles of my brothers.

     

    We all know that there is a startActivity method in the Context. The Activity inherits from the Context and the startActivity method is overloaded. If you use the startActivity method of Activity, there is no restriction. If you use the startActivity method of Context, you need to start a new task and encounter the exception above, it is because the startActivity method of Context is used. The solution is to add a flag.

     

    [Java] 
    1. Intent. addFlags (Intent. FLAG_ACTIVITY_NEW_TASK );

        

       In this way, you can start the Activity in the new task.