Hello,
I was trying out Urho3D on Android, and checking the forums, it seems that some people had success on running the Launcher app, however, I can’t get it to install. Is anyone having the same issue? I know the Android build had some changes recently, but it seems that people managed to get it working.
In some cases the application fails to install on my phone when the Google Play app has access to the internet. It’s a random issue not just with the Urho3D app.
Yeah I saw something about the google app store scanner messing up with the installation, so I disabled it. I tried installing it without internet, but it’s still failing. It fails to install too on android emulator (tried Android 8 and 9).
I almost always use SHARED lib type during development of the build script and I have never encountered any installation error before, at least not the one you guys described above.
I followed the tutorial on here, so I’m assuming that’s the way you compiled it? I’m using Linux and Android Studio btw
Yes. That is the right page. That section was rewritten by me, unless I have I forgotten anything then what’s described in there is how I do the Android build.
I am using Linux host and IntelliJ IDEA as my IDE. I also just invoke Grade wrapper via CLI. At the initial stage I used Android Studio too. After the Gradle version upgrade recently, I believe you need to use preview version of the Android Studio. I wonder that is the cause. Using IntelliJ IDEA allows me to explore the bleeding edge of the Gradle with no sweat.
Tried again but this time building with ./gradlew build, same thing. As for the version, I’m using the Canary build of Android Studio, since it’s the only one that uses Gradle 3.5.
It’s not clear from your post what exactly is failing , any errors ? .
I don’t have any issues with either compiling or installing on any android device with any version ( I have many of them 
) , never tried it on an emulator .
The following works for me ( I am using Mac , but I guess it should work also on a Linux machine)
Make sure that your .bashrc is configured correctly specifically these environment variables should be set pointing to your SDK and NDK.
ANDROID_NDK_HOME
ANDROID_NDK
ANDROID_HOME
In addition your PATH (in .bashrc) should also contain “Android/sdk/tools”
For development I am using
./gradlew assembleDebug -P URHO3D_LUA=0 -P ANDROID_ABI=armeabi-v7a -P URHO3D_ANGELSCRIPT=1
The generated APK can be found in
Urho3D/android/launcher-app/build/outputs/apk/debug/launcher-app-armeabi-v7a-debug.apk
installing using adb
adb install -r launcher-app-armeabi-v7a-debug.apk
Ok gonna try to do it that way, will update shortly.
And about that error, that’s the thing, it just fails to install with no error whatsoever. Here is a print from the emulator, and there’s no log too. The .apk I trying to install is the one generated on the release build named “launcher-app-release-unsigned.apk”.
Well the error is obvious , your apk is not signed .
launcher-app-release-unsigned.apk
You have to sign it with release keys.
using my way it will sign it with debug keys , will allow you to install it .
Once again I am not sure that using an emulator is the right way to go , you have to try it on a real device
Well, that may be, however, I enabled the installation from unknown sources, so that shouldn’t be an issue. However who knows, I will try it later. I also tried on a real device, same thing.
Update: following your way it works just fine! Apparently even if you turn on accept unknown sources on the android settings, you still gotta sign it. After following the tutorial here I self-signed the .apk and now it installs just fine.
Thanks everyone for your help.
Glad you figured it out already. Just want to add that using the IDE then one can install by a click of a button. 
Dammit, now what’s happening is that when I build the release version of the launcher app, I can’t run any examples, they all crash. There’s no log output either.
So there’s no way to get it running on release? You guys always use it on debug?
Yes , it’s a known issues , there are some threads talking about it .
The fix is very simple
You have to modify 2 functions as shown below
unsigned VectorBuffer::Write(const void* data, unsigned size)
{
if (!size)
return 0;
if (size + position_ > size_)
{
size_ = size + position_;
buffer_.Resize(size_);
}
auto* srcPtr = (unsigned char*)data;
unsigned char* destPtr = &buffer_[position_];
position_ += size;
memcpy(destPtr, srcPtr, size);
return size;
}
unsigned MemoryBuffer::Write(const void* data, unsigned size)
{
if (size + position_ > size_)
size = size_ - position_;
if (!size)
return 0;
auto* srcPtr = (unsigned char*)data;
unsigned char* destPtr = &buffer_[position_];
position_ += size;
memcpy(destPtr, srcPtr, size);
return size;
}
Thanks, honestly it wouldn’t be such a big issue if it weren’t for the way larger file size 
By changing those funcs nothing else changes? What’s the downside?
There is no downside , the upside is that it fixes unaligned write on ARM
You can read about it in https://github.com/urho3d/Urho3D/issues/2386
It should be merged into master
PR is welcome…
Done
20 characters .
Thanks for your PR. It is merged.
While working on my code
I found one more use case of Android crash in ARM/release configuration while calling MemoryBuffer::Read() or VectorBuffer::Read()
Previous fix was for crash on MemoryBuffer::Write() , VectorBuffer::Write()
updated the PR
Yeah, I also have a feeling the same pattern of code might get used in a few places in our code base.