Getting "system.entrypointnotfoundexception: loadlibrary" While trying to use SevenZipLib.dll to uncompress the .7z file containing media contents/file in the Android evn.
Context:
-The whole program is written in c# as a MONO Android Project. No Build/Deployment Error/warnings.
While running the apk, its throwing "system.entrypointnotfoundexception: loadlibrary".
-Also tested the same code as windows project (not mono) - uncompressing in the windows evn.
Assumptions for the issue:
7zip internally might be using COM components & Mono frame work is not supporting.
Question:
Has anyone come across similar issue? Please suggest some alternative dll/framework which can be used by my apk for uncompressing the .7z file.
Assuming that SevenZipLib.dll is the SevenZipLib Library on CodePlex, the problem is SevenZipLib\SevelZipLib\SevenZipArchive.cs:
[DllImport("kernel32.dll", CharSet = CharSet.Auto, SetLastError = true)]
private static extern SafeLibraryHandle LoadLibrary(
[MarshalAs(UnmanagedType.LPTStr)] string lpFileName);
The project contains numerous P/Invokes into kernel32.dll (LoadLibrary(), GetProcAddress(), FreeLibrary()), ole32.dll (PropVariantClear()), oleaut32.dll (SafeArrayCreateVector()), and more.
In short, this library is intimately tied to Windows, and isn't going to work on a non-Windows platform in any meaningful fashion, not without a lot of work.
If you need 7z support in a Mono for Android application, you'll need to look into a different library. It looks like the 7-zip SDK includes C# source for reading LZMA files that doesn't rely on P/Invoke, so perhaps that would work?
Related
I have an Android native library (C++ code base) called:
libserverapp.so
And I cannot get the Android build to find it:
"DllNotFoundException: serverapp"
I am using an internal build system, but when I parse the output of the build process, I can see many calls of the form:
android-ndk/toolchains/arm-linux-androideabi-4.6/prebuilt/windows/bin/arm-linux-androideabi-g++.exe -march=armv7-a
After building my Android app, I inspect the resulting APK (renaming to .zip and extracting), and can see my library file here:
lib/armeabi-v7a/libserverapp.so
I can confirm that "ARMv7" is the target architecture in the Android Player settings, and I access the library, in C#, via:
[DllImport("serverapp", CallingConvention = CallingConvention.Cdecl)]
private static extern void run_sim(StringBuilder matchInput, StringBuilder results, int randomSeed);
I have built a Windows DLL of the C++ code, to use in the Editor, and everything works great. However, when I move to Android, the .so cannot be found. The import settings for libserverapp.so are:
Platform: Android; CPU: ARMv7; Path: Assets/Plugins/Android/libserverapp.so; Type: Native
Given that the final APK includes the .so where I expect it to be (lib/armeabi-v7a/), I assume my Unity settings are correct? Also, I am not using IL2CPP for the Android build.
Finally, when I do an object dump of the library file (using arm-linux-androideabi-objdump.exe), the file format of the library file is "elf32-littlearm".
I feel that the issue here is simply finding the .so, not the functionality within it. Any ideas on what's going on here?
Thanks!
I ended up solving the problem. I mentioned that was using an internal build system. Well, there seems to be a bug in it. I ported things over to official Android NDK makefiles, and then it "just worked". So in this case, the library could be found, but its contents weren't valid.
is there someone who has experience with pyqtdeploy and adding external modules? I am currently using pyqtdeploy (version 1.2) together with PyQt 5.5.1 to write an application that can be deployed to an Android device. Without any external modules, the freezing with pyqtdeploy works pretty well. However, I am not really sure how I can add external modules (not pure Python ones) to my application.
In particular, I want to add the external module pycrypto. Therefore, I downloaded the pycrypto sourcecode, compiled it with the Android toolchain (from the Android NDK) and now I have a bunch of *.py and *.so files. How can I add them to my application?
My initial attempt was to add the *.py and the *.so files (so basically the whole pycrypto module) to the "Other Packages" tab in pyqtdeploy.
But now, when I import something pycrypto related in my application (from Crypto.Cipher import AES) i get the following error message:
File: ":/Crypto/Cipher/_AES.py", line 20 in __bootstrap__
TypeError: 'NoneType' object is not callable
The _AES.py file where the error is thrown, looks like this:
def __bootstrap__():
global __bootstrap__, __loader__, __file__
import sys, pkgutil, imp
__file__ = pkgutil.get_data(__name__,'_AES.cpython-34m.so')
__loader__ = None; del __bootstrap__, __loader__
imp.load_dynamic(__name__,__file__)
__bootstrap__()
At first I thought, that the *.so filename was just wrong and therefore, I got the NoneType Error, so I changed the filename in _AES.py to something other like 'test.so'. Surprisingly, now, I get a different error message than before:
File ":/pkgutil.py" line 629, in get_data
ImportError: qrcimporter: error opening file :/Crypto/Cipher/test.so
Ok, so the filename should be fine, right? But why do i get the 'NoneType` error message? What am I doing wrong? Is this the right way to accomplish this?
Any help is highly appreciated. I am pretty sure, that i'm only one small step away from getting this thing to work, but I can't figure out what i'm doing wrong.
Thanks!
I'm using ruboto (ruby) on an android tablet. I'd like my source to be in a subdirectory of the usual default source directory. Is there a way to do this?
You have not stated your motivation for placing the Ruby source in a subdirectory, so I'll speculate that it is for tidiness in a polyglot environment. Also, I'll assume you want all the Ruby source in the same directory, including source for Activity classes.
Adding your path to both the Ruby $LOAD_PATH and the Android component search path has been combined into one method in org.ruboto.JRubyAdapter.addLoadPath. In JRubyAdapter.setUpJRuby, you can find a call to addLoadPath around line 289: https://github.com/ruboto/ruboto/blob/1.4.0/assets/src/org/ruboto/JRubyAdapter.java#L289
You can add your own call below the existing one:
addLoadPath("file:" + apkName + "!/<your_path_here>")
That will add the path to the Ruby load path and the Android component search path.
If you have a clear use case, I would submit it to the Ruboto tracker at https://github.com/ruboto/ruboto/issues . It sounds like something more Ruboto developers could use.
I am attempting to build an Android app that makes use of boost serialization. I have built the library against NDK r8d using arm 4.7's g++. When I go to compile my native code into a library using ndk-build, however, I get "undefined reference to 'mbtowc'" and "undefined reference to 'wctomb'" when the compiler attempts to link some code from Archive headers in boost.
I cannot seem to get a clear answer as to whether the NDK supports these functions.
Although it implements the functions, the CrystaX NDK is not an option as it has known crashes when using it with Boost, according to the Boost mailing list.
So, if the NDK does implement these functions somehow, why is NDK-build unable to link against them? I can find reference to them in cstdlib within the NDK, and I believe there may be a flag I need to set, but I'm not sure how or where to do so.
If there is no implementation of them, does anyone have any advice on how I can write them myself? I know roughly what mbtowc and its complement are supposed to do, but without much experience writing low-level C, and without much knowledge of Android / ARM architecture, I could really use some advice on doing so.
#ifdef ANDROID
int wctomb(char *s, wchar_t wc) { return wcrtomb(s,wc,NULL); }
int mbtowc(wchar_t *pwc, const char *s, size_t n) { return mbrtowc(pwc, s, n, NULL); }
#endif
Findings! Yes, boost has options to build it without requiring wchar support by adding preprocessor definitions to the boost build scripts. Boost still crashes when built using them at the line of code where I attempt to serialize an object to file. (the crash is a generic segfault at 0x00000000, and I was unable to gain any useful information).
So, I haven't bothered writing wctomb or its inverse. I shouldn't need to, is the answer to my question, although in the end the answer to the question doesn't matter.
To further clarify: don't bother doing what I've been trying to do. If you have been using Boost's serialization library and want your code to run on android ndk r8d or earlier, just give up. Write a serializer yourself, because there is no useful information to be found on how to make Serialization work. Hopefully a future release of the ndk fixes this problem, but for now I have no choice but to just rewrite everything.
I had the same problem. I was creating an android port for code that uses boost::serialization.
My code failed to compile because of missing implementation of mbtowc / wctomb (mb: multi-byte (char), wc: (wide-char)'
Implementation of these functions will probably be tricky cause as far as I know the wide-char for android is a single byte char instead of a true wide character..
However when I compiled boost with -DBOOST_NO_STD_WSTRING the link errors disappeared and I could use boost::archive::text_iarchive & boost::archive::text_oarchive on android.
I am now serializing STL containers of numerics and std::strings without a problem.
I compiled boost for android following the advice on this link: http://www.codexperiments.com/android/2011/05/tips-tricks-building-boost-with-ndk-r5/
I am using boost-1.55_0 and NDK r9c.
I added the following <compileflags>-DBOOST_NO_STD_WSTRING to the build command so it would build serialization library without wide character support.
I currently developing app for Android that provides various audio settings. I use android system prepared by someone else, and it provides (I see in source and compiled files) some methods that could be useful for me. For example there are (kernel/drivers/audio/audio.c) some methods to change bands (for equalizer). In compiled system there is audio_setting.so file in some audio dir on kernel. Is there a possibility to use this methods (library) in my application NDK? I don't want to compile my app with whole system, rather to dynamically add this lib.
edit:
It was simplier than I thought. I used:
void *some_lib;
bundlewrapper = dlopen("some/path/some_lib.so", RTLD_LAZY);
if ( some_lib!= NULL ) {
LOGV("Loaded lib\n");
// use methods from lib
}
Sure, you can use any code on the system.
Obviously if it is non-JNI code you'll have to call it from your own JNI code or wrapper.
In your Android.mk file you will need to add the extra lib in LOCAL_LDLIBS