Load Activity and/or Application Logo Programmatic

问题:

I am trying to load the logo associated with the current activity and/or its parent application from the definition in the manifest. This technique has already worked successfully on loading the title and icon associated with both, but the logo is always returning null or 0.

Here is the relevant info from the manifest I am working with:

<application
    android:icon="@drawable/ic_launcher"
    android:logo="@drawable/ad_logo"
    android:label="@string/app_name"
    android:hardwareAccelerated="true">

    <activity
        android:name=".MainActivity" 
        android:label="@string/app_name"
        android:logo="@drawable/ad_logo">

With activity being an instance of the above defined activity, I have tried the following (results annotated inline):

PackageManager pm = activity.getPackageManager();
ComponentName cn = activity.getComponentName();
ApplicationInfo ai = activity.getApplicationInfo();

//ACTIVITY LABEL: Works
pm.getActivityInfo(cn, PackageManager.GET_ACTIVITIES).loadLabel(pm);

//APPLICATION LABEL: Works
ai.loadLabel(pm);
//APPLICATION LABEL: Works
pm.getApplicationLabel(ai);

//ACTIVITY ICON: Works
pm.getActivityInfo(cn, PackageManager.GET_ACTIVITIES).loadIcon(pm);
//ACTIVITTY ICON: Works
pm.getActivityIcon(cn);

//APPLICATION ICON: Works
pm.getApplicationIcon(ai);
//APPLICATION ICON: Works
ai.loadIcon(pm);

//ACTIVITY LOGO: Does not work
pm.getActivityInfo(cn, PackageManager.GET_ACTIVITIES).loadLogo(pm);
//ACTIVITY LOGO: Does not work
pm.getActivityInfo(cn, PackageManager.GET_ACTIVITIES).logo
//ACTIVITY LOGO: Does not work
pm.getActivityLogo(cn);

//APPLICATION LOGO: Does not work
pm.getApplicationLogo(ai);
//APPLICATION LOGO: Does not work
pm.getApplicationLogo(activity.getApplication().getPackageName());
//APPLICATION LOGO: Does not work
ai.loadLogo(pm);

//APPLICATION LOGO: Does not work
pm.getApplicationInfo(ai.packageName, 0).loadLogo(pm);
//APPLICATION LOGO: Does not work
ai.logo;

Does anyone know how to properly load the logo for either or both of these targets?

edit: Logo support requires API level 9. The devices I am testing on are emulators and physical devices all runing API level 10. This code will never be executed on 3.0+.

回答1:

From my tests, your code works properly running on a Honeycomb device, but not on a Gingerbread or below device. That seems to imply that the android:logo functionality, although present in API Level 8, is not implemented correctly in the underlying platform. That is, the same application apk on a Level 8-10 device is not retaining the logo attribute, but a Level 11 device does. That means the problem is not with the code or the AndroidManifest.xml, but with the platform.

回答2:

If you take a look at the code in android.app.ContextImpl.ApplicationPackageManager (here), you will find that eventually it uses the method

public Drawable getDrawable(String packageName,int resid,ApplicationInfo appInfo)

(lines 2131 to 2173 in 2.3).

There are several Log.w calls there that you can use to follow what is going on through adb (i.e., Failure retrieving resources for...)

回答3:

First you need to find all the applications that are installed. For this purpose us the following methods from package manager,

public abstract List<PackageInfo> getInstalledPackages (int flags)

more info here

You can also use the following method for getting info on installed packages.

public abstract List<ApplicationInfo> getInstalledApplications (int flags)

more info here

Now after getting the list, iterate it using the following method.

public Drawable getDrawable(String packageName,int resid,ApplicationInfo appInfo)

more info here

Each iteration will give you the respective drawable of the package queried. here res id is the id of the icon..

R.drawable.icon

回答4:

@Jake Wharton, you are trying to retrieve something that doesn't exist. Unlike applications, activities do not have a separate logo attribute (the logo defined in the application becomes the default attribute for all activities). This is why you are unable to retrieve one from an activity.