Can I update an Android provider.Settings.System value?

I can read settings like this, for example:

final String mytest = System.getString(this.getContentResolver(), System.AIRPLANE_MODE_O开发者_如何学CN);

...but can't seem to write to settings using putString, no matter what I've tried. Maybe it is the scope of this.getContentResolver()??? I'm a newbie, so who knows, maybe it can't be done, or it's just syntax? Currently the code is in the onCreate of an Activity class.

Any insight is much appreciated.

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Have you given your app WRITE_SETTINGS permission in AndroidMainfest.xml?

If not you will see this:

E/AndroidRuntime(11614): Caused by: java.lang.SecurityException: Permission Denial: writing com.android.providers.settings.SettingsProvider uri content://settings/system from pid=11614, uid=10053 requires android.permission.WRITE_SETTINGS

I strongly advise looking at the log output when debugging this kind of thing.