Android 4.0: widgets not appearing?

问题

I have a widget I created against Android 2.1 that's been fine and selling on the market.

I had a user complain that he bought it and it never showed up on his Android 4.0 device.

I loaded up the 4.0 emulator, ran it from Eclipse, it reported a successful installation and in fact I can see it listed in the "Widget Preview" app, and I can run it there and it seems fine, but it doesn't show up anywhere under "Widgets" -- I can't actually find it to drag it to the home screen! I assume this is the same thing the user is seeing.

Any idea what's going on here? Why is it fine in 2.1 but doesn't show up in the list on 4.0, even after a successful install?

This is my layout\widget.xml file, if that's any help:

<RelativeLayout android:id="@+id/relativeLayout1" android:layout_width="fill_parent" android:layout_height="fill_parent" xmlns:android="http://schemas.android.com/apk/res/android">
    <TextView android:layout_width="wrap_content" android:id="@+id/blankspot" android:layout_height="5dp" android:gravity="center" android:shadowDy="1" android:shadowDx="1" android:layout_centerHorizontal="true"></TextView> 
    <ImageButton android:layout_below="@+id/blankspot" android:layout_width="60dp" android:layout_height="60dp" android:id="@+id/widgetIconButton" android:layout_centerHorizontal="true" android:scaleType="centerCrop" android:src="@drawable/volumeprofilesplus" android:background="@null"></ImageButton>
    <ImageView android:layout_width="60dp" android:layout_height="20dp" android:id="@+id/override" android:layout_centerHorizontal="true" android:layout_centerVertical="true" android:scaleType="fitXY" android:background="@null" android:src="@drawable/overredcaps" android:visibility="invisible"></ImageView>
    <ImageButton android:layout_below="@+id/widgetIconButton" android:layout_width="70dp" android:layout_height="30dp" android:id="@+id/widgetSettingsButton" android:layout_centerHorizontal="true" android:scaleType="fitXY" android:src="@drawable/settings" android:background="@null"></ImageButton>
</RelativeLayout>

And the xml\widget_provider.xml:

<?xml version="1.0" encoding="utf-8"?>
<appwidget-provider
    xmlns:android="http://schemas.android.com/apk/res/android"
    android:minWidth="72dip"
    android:minHeight="72dip"
    android:updatePeriodMillis="0"
    android:initialLayout="@layout/main" >    
</appwidget-provider>

回答1:

So here's the solution I came up with:

You need an activity that will appear on the launcher. So first we have ye olde widget receiver, like so:

<receiver android:name=".VolumeProfilesWidget" android:label="@string/app_name">
    <intent-filter>
        <action android:name="android.appwidget.action.APPWIDGET_UPDATE" />                
        <!-- Broadcast Receiver that will also process our self created action -->
        <action android:name="net.thepurge.volumeprofiles.plus.VolumeProfilesWidget.ACTION_WIDGET_RECEIVER"/>               
    </intent-filter>
    <meta-data android:name="android.appwidget.provider" android:resource="@xml/volumeprofiles_widget_provider" />
</receiver>

And then we need some activity, with the MAIN and LAUNCHER set:

<activity android:name=".MainActivity"
          android:label="@string/app_name">
    <intent-filter>
        <action android:name="android.intent.action.MAIN" />
        <category android:name="android.intent.category.LAUNCHER" />                
        <action android:name="net.thepurge.volumeprofiles.plus.VolumeProfilesWidget.ACTION_WIDGET_CONFIGURE"/>
    </intent-filter>
</activity>

As far as I can tell you MUST do this even if your widget is just supposed to be a pure widget with no associated activities. At the very least, make one dummy activity that launches a screen that says "Your widget is now ready for use! Look for it under widgets and drag it to your home screen!"

In my case, my widget launched an activity when you pushed it, so I made that activity into LAUNCHER/MAIN and just added a one-time popup dialog that basically says "you can run this as an application but you may want to use the widget instead".

Note that on the 4.0 emulator, I was never getting my widget to show up on a first time install prior to this change. Simply having an activity set to MAIN and LAUNCHER seemed to be enough to make the widget show up.

回答2:

After days i figured out the solution

so lets go to any of your activities that will be the launched when you open the app and in the main activity add only this line

sendBroadcast(new Intent(Intent.ACTION_MAIN).addCategory(Intent.CATEGORY_HOME));

as example

public class Default class extends Activity  {


@Override
protected void onCreate(Bundle savedInstanceState) {
    // TODO Auto-generated method stub
    super.onCreate(savedInstanceState);
       sendBroadcast(new Intent(Intent.ACTION_MAIN)
       .addCategory(Intent.CATEGORY_HOME));
    setContentView(R.layout.main);



}

that's it , this will give the system that the main app is now running and it will get the widget out to the launcher :) simple line that's it don't modify anything in the manifest just keep the way you developed ur app that shows widget normaly in the previous versions < 4.x

回答3:

Got the same problem. I fixed it by deleting <PreferenceScreen> tags in my appwidgetprovider.xml(located in res/xml).

回答4:

You need to manually start the associated app at least once to get the widget to show up. Before that it is in a non-runnable state and it won't receive broadcasts, etc.

回答5:

My solution (Widget on 4.1.2) was be sure that widget was installed on the internal device storage.

According to: Android Documentation: install-location, you should not install widgets on External Storage.

I had to uninstall my widget, install it again and after that i saw the changes !

Useful link:

http://www.technipages.com/fix-android-app-widgets-not-appearing-on-widget-list

来源：https://stackoverflow.com/questions/8794952/android-4-0-widgets-not-appearing