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问题:
I\'m trying to install apps from Google Play. I can understand that on opening the Google Play store URL, it opens the Google Play and when I press the back button, the activity resumes.
Intent marketIntent = new Intent(Intent.ACTION_VIEW, Uri.parse(appURL));
marketIntent.addFlags(Intent.FLAG_ACTIVITY_NO_HISTORY | Intent.FLAG_ACTIVITY_CLEAR_WHEN_TASK_RESET);
startActivity(marketIntent);
When I went back to the activity, I tried calling this onResume()
to check if the app is installed, but I receive an error:
@Override
protected void onResume() {
super.onResume();
boolean installed = false;
while (!installed) {
installed = appInstalledOrNot(APPPACKAGE);
if (installed) {
Toast.makeText(this, \"App installed\", Toast.LENGTH_SHORT).show();
}
}
}
private boolean appInstalledOrNot(String uri) {
PackageManager pm = getPackageManager();
boolean app_installed = false;
try {
pm.getPackageInfo(uri, PackageManager.GET_ACTIVITIES);
app_installed = true;
}
catch (PackageManager.NameNotFoundException e) {
app_installed = false;
}
return app_installed ;
}
The error is as follows:
E/AndroidRuntime(796): java.lang.RuntimeException: Unable to start
activity
ComponentInfo{com.example.appinstaller/com.example.appinstaller.MainActivity}:
android.content.ActivityNotFoundException:
No Activity found to handle Intent { act=android.intent.action.VIEW
dat=market://details?id=com.package.name flg=0x40080000 }
I guess the activity is onPause()
. Is there a better way to implement it? I\'m trying to check if the app has finished installing.
回答1:
Try this:
private boolean isPackageInstalled(String packageName, PackageManager packageManager) {
boolean found = true;
try {
packageManager.getPackageInfo(packageName, 0);
} catch (PackageManager.NameNotFoundException e) {
found = false;
}
return found;
}
It attempts to fetch information about the package whose name you passed in. Failing that, if a NameNotFoundException
was thrown, it means that no package with that name is installed, so we return false
.
Note that we pass in a PackageManager
instead of a Context
, so that the method is slightly more flexibly usable and doesn\'t violate the law of Demeter. You can use the method without access to a Context
instance, as long as you have a PackageManager
instance.
Use it like this:
public void someMethod() {
// ...
PackageManager pm = context.getPackageManager();
boolean isInstalled = isPackageInstalled(\"com.somepackage.name\", pm);
// ...
}
回答2:
Robin Kanters\' answer is right, but it does check for installed apps regardless of their enabled or disabled state.
We all know an app can be installed but disabled by the user, therefore unusable.
This checks for installed AND enabled apps:
public static boolean isPackageInstalled(String packageName, PackageManager packageManager) {
try {
return packageManager.getApplicationInfo(packageName, 0).enabled;
}
catch (PackageManager.NameNotFoundException e) {
return false;
}
}
You can put this method in a class like Utils
and call it everywhere using:
boolean isInstalled = Utils.isPackageInstalled(\"com.package.name\", context.getPackageManager())
回答3:
Try this:
public static boolean isAvailable(Context ctx, Intent intent) {
final PackageManager mgr = ctx.getPackageManager();
List<ResolveInfo> list = mgr.queryIntentActivities(intent,PackageManager.MATCH_DEFAULT_ONLY);
return list.size() > 0;
}
回答4:
Faster solution:
private boolean isPackageInstalled(String packagename, PackageManager packageManager) {
try {
packageManager.getPackageGids(packagename);
return true;
} catch (NameNotFoundException e) {
return false;
}
}
getPackageGids
is less expensive from getPackageInfo
, so it work faster.
Run 10000 on API 15
Exists pkg:
getPackageInfo: nanoTime = 930000000
getPackageGids: nanoTime = 350000000
Not exists pkg:
getPackageInfo: nanoTime = 420000000
getPackageGids: nanoTime = 380000000
Run 10000 on API 17
Exists pkg:
getPackageInfo: nanoTime = 2942745517
getPackageGids: nanoTime = 2443716170
Not exists pkg:
getPackageInfo: nanoTime = 2467565849
getPackageGids: nanoTime = 2479833890
Run 10000 on API 22
Exists pkg:
getPackageInfo: nanoTime = 4596551615
getPackageGids: nanoTime = 1864970154
Not exists pkg:
getPackageInfo: nanoTime = 3830033616
getPackageGids: nanoTime = 3789230769
Run 10000 on API 25
Exists pkg:
getPackageInfo: nanoTime = 3436647394
getPackageGids: nanoTime = 2876970397
Not exists pkg:
getPackageInfo: nanoTime = 3252946114
getPackageGids: nanoTime = 3117544269
Note: This will not work in some virtual spaces. They can violate the Android API and always return an array, even if there is no application with that package name.
In this case, use getPackageInfo
.
回答5:
@Override
protected void onResume() {
super.onResume();
boolean installed = false;
while (!installed) {
installed = appInstalledOrNot (APPPACKAGE);
if (installed) {
Toast.makeText(this, \"App installed\", Toast.LENGTH_SHORT).show ();
}
}
}
private boolean appInstalledOrNot (String uri) {
PackageManager pm = getPackageManager();
boolean app_installed = false;
try {
pm.getPackageInfo(uri, PackageManager.GET_ACTIVITIES);
app_installed = true;
} catch (PackageManager.NameNotFoundException e) {
app_installed = false;
}
return app_installed;
}