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Android Android Lists and Adapters (2015) Standard ListViews Introducing ListView and ListActivity

Payton Dwight
Payton Dwight
5,751 Points
Posted by Payton Dwight
Payton Dwight
5,751 Points

New Empty Activity Warnings

http://imgur.com/a/UyxQx

I googled around a bit and was unsuccessful. Another treehouse student had the same problem, but his question never got answered: https://teamtreehouse.com/community/warning-when-creating-an-empty-activity-what-does-it-mean

I tried to rebuild. I tried changing my dimens.xml before creating a new activity like so:

<dimen name="activity_horizontal_margin">16dp</dimen>

(because it seems like this is the culprit?). And I fiddled around with the activity_daily_forecast.xml (deleting the margins) to no avail.

Please help!

Thanks in advance.

Ben Jakuben
Ben Jakuben
Treehouse Teacher
Ben Jakuben
Ben Jakuben
Treehouse Teacher

I'm in the process of refreshing this course to avoid these types of issues. Sorry for the trouble! I'm currently away from my computer but I can take a look at this issue first thing tomorrow morning.

Payton Dwight
Payton Dwight
5,751 Points
Payton Dwight
Payton Dwight
5,751 Points

Sweet, thanks Ben. I performed "undo" and "safe delete" on a few of the new empty activities (DailyForecastActivity) I created whilst trying to troubleshoot. I hope this didn't mess up anything behind the scenes.

2 Answers

Payton Dwight
Payton Dwight
5,751 Points
Payton Dwight
Payton Dwight
5,751 Points

This was the issue the whole time:

import pmdparadox.com.stormy.R;

was not present...

ah! Thanks, Ben.

Ben Jakuben
Ben Jakuben
Treehouse Teacher
Ben Jakuben
Ben Jakuben
Treehouse Teacher

Ah! Missing import statement are the wooorst!

Gwinyai Nyatsoka
Gwinyai Nyatsoka
7,428 Points

This was the correct solution. I wonder why it forgets to import that file when the Activity is created.

Ben Jakuben
STAFF
Ben Jakuben
Treehouse Teacher
Ben Jakuben
Ben Jakuben
Treehouse Teacher

Okay, I haven't seen this error before and did a little digging. I was able to recreate the warning very easily. I chose to ignore the warning and keep the files, and these are working (here are my dimens.xml and layout files):

dimens.xml

<resources>
    <!-- Default screen margins, per the Android Design guidelines. -->
    <dimen name="activity_horizontal_margin">32dp</dimen>
    <dimen name="activity_vertical_margin">16dp</dimen>
</resources>

activity_daily_forecast.xml

<?xml version="1.0" encoding="utf-8"?>
<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:tools="http://schemas.android.com/tools"
    android:id="@+id/activity_test_forecast"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:paddingBottom="@dimen/activity_vertical_margin"
    android:paddingLeft="@dimen/activity_horizontal_margin"
    android:paddingRight="@dimen/activity_horizontal_margin"
    android:paddingTop="@dimen/activity_vertical_margin"
    tools:context="teamtreehouse.com.stormy.ui.TestForecastActivity">

</RelativeLayout>

Notice that my default dimens.xml file has a comment about default screen margins per the Android Design guidelines. I couldn't find specific guidelines for margins with a little bit of digging in the design guidelines.

I did find a reference in JetBrain's code to this type of warning. See line 128 here: https://github.com/JetBrains/android/blob/master/android/src/com/android/tools/idea/templates/RecipeMergeUtils.java

It looks like Android Studio is checking for values against some guidelines, but that the guidelines were updated and Android Studio is now throwing a warning for this difference. I'm not sure if 16dp or 32dp is the recommended margin at this point, but it doesn't really matter. I'll stick with 32dp since that's the new default.

Let me know if you're having any trouble with the code itself, but this should be safe to ignore!