Develop Reference

APK not running on real device - Manifest error?

I am new on app's code. My project runs perfectly on emulators. However the apk is not running in my samsung device. Checking it with the Android Studio Analyzer the line xmlns:android="http://schemas.android.com/apk/res/android" in the manifest.xml returns in red. It seems that something is wrong with my project Manifest. Any Help? My manifest is copied below.
<?xml version="1.0" encoding="utf-8"?>
<manifest
xmlns:android="http://schemas.android.com/apk/res/android"
android:versionCode="1"
android:versionName="1.0"
package="com.ferleecidade.a100dia11">
<uses-sdk
android:minSdkVersion="16"
android:targetSdkVersion="26" />
<application
android:theme="#ref/0x7f0f0005"
android:label="#ref/0x7f0e001f"
android:icon="#ref/0x7f0c0000"
android:debuggable="true"
android:exported="true"
android:allowBackup="true"
android:supportsRtl="true"
android:roundIcon="#ref/0x7f0c0002">
<activity
android:name="com.ferleecidade.a100dia11.MainActivity">
<intent-filter>
<action
android:name="android.intent.action.MAIN" />
<category
android:name="android.intent.category.LAUNCHER" />
</intent-filter>
</activity>
<activity
android:name="com.ferleecidade.a100dia11.MyCustomList" />
<meta-data
android:name="preloaded_fonts"
android:resource="#ref/0x7f020003" />
<meta-data
android:name="android.support.VERSION"
android:value="26.1.0" />
<meta-data
android:name="android.arch.lifecycle.VERSION"
android:value="27.0.0-SNAPSHOT" />
</application>
</manifest>

Help? Yes.
I am actively looking into this right now.
I don't believe your manifest is causing this or at least isn't the sole cause.
I have a project that I can run on my devices and emulators and deploy without a glitch.
I also get an error on the same line you do when analyzing the APK (Build/.Analyze APK).
If you hover your cursor over the red text you will see your error popup.
Mine says "URI is not registered (Settings | Languages and Frameworks | Schemes and DTDs)"
I performed a quick experiment.
created a brand new project in Android Studio with a single activity.
Cleaned the project.
Ran in an emulator.
Generated a signed APK.
Analyzed the APK and the error is there.
I suggest you try this.
This leads me to believe one of two things.
There is something wrong with my default project settings.
The error is being incorrectly reported by Android studio.
I hope this was useful.

MainActivity NoClassDefFoundError

I seem to be having a similar problem to a myriad of the community; however, I don't seem to have the same symptoms (or at the very least, my Google-fu is not allowing me to find it).
Long story short: The app is giving me java.lang.RuntimeException: Unable to instantiate activity.
From what I understand this can only be caused by improper order of loading libraries or by missing the file in the AndroidManifest.xml.
Here is my AndroidManifest.xml
<?xml version="1.0" encoding="utf-8"?>
<manifest xmlns:android="http://schemas.android.com/apk/res/android"
package="net.alexanderlyons.livingpokedex">
<uses-permission android:name="android.permission.INTERNET" />
<application
android:allowBackup="true"
android:icon="#mipmap/ic_launcher"
android:label="#string/app_name"
android:supportsRtl="true"
android:theme="#style/AppTheme">
<activity android:name=".MainActivity">
<intent-filter>
<action android:name="android.intent.action.MAIN" />
<category android:name="android.intent.category.LAUNCHER" />
</intent-filter>
</activity>
</application>
Here is a link to my repository for those wanting to build it themselves. If anyone can give me insight as to what might be wrong.
Note: This may be due to my .gitignore, as the last time I built, it was on my main tower. I am only running into this issue on a remote machine.
TL:DR - My MainActivity is not loading, it exists in the AndriodManifest.xml, and I am only using gradles to load files, not local jars.

Your problem can be caused by different things, but the most common of it is you having too many libraries loaded, with too many methods.
You should enable multidex in your app, here's the guide:
multidex
A quick tutorial:
Add "multiDexEnabled true" to your gradle config (under target sdk version, for example).
Add this to your dependencies:
dependencies {
compile 'com.android.support:multidex:1.0.0'
}
And make sure you application extends this:
<application
...
android:name="android.support.multidex.MultiDexApplication">
...
</application>
Either via code or via manifest.
Edit:
Test the project with the build tools 22, sd version 22 and target 22. Also, use the support libraries 22.+

Error: Could not find MyFirstApp.apk

I am following he tutorial from this site: http://developer.android.com/training/basics/firstapp/creating-project.html, but when I run the default program in eclipse when an android project is created, it gives me the error R could not be found. To fix this, I commented out the lines with R and ran it again, but now it gives me the error: Could not find MyFirstApp.apk!... I have tried all other solutions on this site, but none of them work. If anybody knows how to fix this, please let me know!
here is my manifest file:
<?xml version="1.0" encoding="utf-8"?>
<manifest xmlns:android="http://schemas.android.com/apk/res/android"
package="com.example.myfirstapp"
android:versionCode="1"
android:versionName="1.0" >
<uses-sdk
android:minSdkVersion="8"
android:targetSdkVersion="19" />
<application
android:allowBackup="true"
android:icon="#drawable/ic_launcher"
android:label="#string/app_name"
android:theme="#style/AppTheme" >
<activity
android:name="com.example.myfirstapp.MainActivity"
android:label="#string/app_name" >
<intent-filter>
<action android:name="android.intent.action.MAIN" />
<category android:name="android.intent.category.LAUNCHER" />
</intent-filter>
</activity>
</application>
</manifest>

When your .R class could not be found, there is an error in your project - commenting out the lines with the .R class does not fix the problem.
Perhaps you just have to clean your workspace (Project > Clean...) or delete the bin and gen folder in your project, they should be rebuilt automatically.
Look at the Problems tab next to the Console tab where you get the errors and take a look at the messages.

when I had originally installed the android sdk it installed to some folder in my filesystem. I moved the SDK manager to a folder on my desktop, and installed updates through there. I had to change my android path to that folder, and everything fixed! Thanks for your help though, it was much appreciated.

Android Studio installs an APK for each module

I have an project, build with Gradle in Android Studio v 0.3.2.
My project has dependencies to two other modules(android library). The project structure is well defined with build.gradle files.
The problem is... when i run the project on an Android device, i get installed 3 apk's on my device. One is the main project(the only right one) and the other two are from the imported modules(theese two i don't want to get installed).
How can i achieve this? Or what i'm doing wrong?
Project Structure:
MyLibModule
MainProject
MainProject->libraries->MyOtherModule
Where MyLibModule is at the same path as the Main project, because i also need this module in a other project.
Just to be clear: The whole project build's OK, all dependencies are OK, but why do i get 3 APK's on my device?

After a whole day struggling with this problem, i located the cause of this strange behaviour. The problem was the manifest of library module. Before i switched to Android studio i used Eclipse. And i had a testActivity declared in the manifest of the library project. Removing all test activities from the manifest's of my library modules solved the problem. Now Android Studio installs only the MainProject apk.
Some code:
The manifest of MyLibModule:
<?xml version="1.0" encoding="utf-8"?>
<manifest xmlns:android="http://schemas.android.com/apk/res/android"
package="com.test.mylibmodule"
android:versionCode="1"
android:versionName="1.0" >
<uses-sdk android:minSdkVersion="7"/>
<application>
<activity
android:name=".TestActivity"
android:label="#string/app_name">
</activity>
</application>
</manifest>
Changed to:
<?xml version="1.0" encoding="utf-8"?>
<manifest xmlns:android="http://schemas.android.com/apk/res/android"
package="com.test.mylibmodule"
android:versionCode="1"
android:versionName="1.0" >
<uses-sdk android:minSdkVersion="7"/>
<application>
</application>
</manifest>
....And the same for MyOtherModule.
NOTE: the empty application node must stay in the manifest, to avoid build errors.

remove the intent-filter from your library's launch activity
<application>
<activity android:name=".MainActivity">
<intent-filter>
<action android:name="android.intent.action.MAIN" />
<category android:name="android.intent.category.LAUNCHER" />
</intent-filter>
</activity>
</application>
Changed to
<application>
<activity android:name=".MainActivity"/>
</application>

It's because your libraries are defined in their build.gradle files as being applications instead of libraries. Look for this line:
apply plugin: 'android'
and replace it with:
apply plugin: 'android-library'
You may need to make other adjustments to the buildfile as well because not everything that applies to applications can be specified in a library buildfile. See http://tools.android.com/tech-docs/new-build-system/user-guide#TOC-Library-projects for more information.

Eclipse - new android activity showing in manifest but missing under src

I created a new blank activity from Eclipse's 'New' menu.
I didn't get any errors, and the activity looks to have been correctly populated in the manifest, however, no java class file has been created.
I get the impression that within Eclipse, the class should have been auto-created and auto-populated with the onCreate and onOptionsItemSelected method templates.
Why didn't Eclipse automatically create the class for me?
Manifest code as requested:
<?xml version="1.0" encoding="utf-8"?>
<manifest xmlns:android="http://schemas.android.com/apk/res/android"
package="com.example.myfirstandroidapp"
android:versionCode="1"
android:versionName="1.0" >
<uses-sdk
android:minSdkVersion="8"
android:targetSdkVersion="16" />
<application
android:allowBackup="true"
android:icon="#drawable/ic_launcher"
android:label="#string/app_name"
android:theme="#style/AppTheme" >
<activity
android:name="com.example.myfirstandroidapp.MainActivity"
android:label="#string/app_name" >
<intent-filter>
<action android:name="android.intent.action.MAIN" />
<category android:name="android.intent.category.LAUNCHER" />
</intent-filter>
</activity>
<activity
android:name="com.example.myfirstandroidapp.DisplayMessageActivity"
android:label="#string/title_activity_display_message"
android:parentActivityName="com.example.myfirstandroidapp.MainActivity" >
<meta-data
android:name="android.support.PARENT_ACTIVITY"
android:value="com.example.myfirstandroidapp.MainActivity" />
</activity>
</application>

The fastest solution: keep the Activity in your manifest, but create the java class by right-clicking your package -> new -> class -> DisplayMessageActivity and then extend the Activity class and add the missing methods. Note that the class name have to match the one declared in the manifest
EDIT
After you've done it, clean the project by selecting project -> clean and check if there are any error messages left

I needed to uninstall Eclipse and install the sdk (adt bundle) from http://developer.android.com/ which comes bundled with eclipse to resolve this issue.
I found that my original set-up not only failed to create source files, but was also unable to create new android projects, even though it managed to create the first project successfully. Something must have happened to ruin the set up, no doubt, something I did but cannot trace.

What worked for me...
In eclipse, go to Help >
Install new software... > Work with: https://dl-ssl.google.com/android/eclipse/
Hit enter, checkmark "Developer Tools" and "NDK Plugins".
Let it download and install. I had to delete "myfirstapp" and remake it.
Restart Eclipse once it has downloaded and installed.
Having that issue and actually doing it over again helped me understand more about the syntax used in the lessons that I've already been through before.