We are new to Android and we are trying to develop a new application. We installed all the basic setup of Android. We tried to run the Android Sample projects in Eclipse. But while to compile the following lines and a few other lines that uses the variable 'R' throws up an error.
setContentView(R.layout.activity_main);
'R cannot be resolved to a variable'. I do not understand what is causing the error. Anyone help me out in this issue.
check that the import for R class is not
import com.android.R;
and you should make it
import yourpackagename.R;
then recompile
Please try to clean the project, and try compiling again.
If not solved, refer to R cannot be resolved - Android error
If you have 64 bit Linux platform without ia32 libraries, then this problem could also occur. It took me quite some time to pin this one down, seeing that the problem is not clearly linked with the inability to execute 32 bit code.
Just make the import part import com.android.R.layout instead of com.android.R
In my case i forgot to re-install the SDK. When you re-install your operating system, you should re-extract (re-install) your SDK Zip file.
Also check that you have your android libraries mapped correctly in the settings for Eclipse (if you are using eclipse to develop).
Check if your resorce name (for example template.xml) has ONLY small caps letters.
import com.packagename.R* will worl
Change import to
import yourpackagename.R;
If error is still there then
go to gen folder->packagename->R.java
and remove error line some times it gave error on drawable files.
setContentView(R.layout.activity_main)
Change the SDK and delete the project and create new ... it will definitely work!
Related
I've followed these instructions for adding OpenCV to a gradle project, and it seemed to go okay, however in my source I can't import the OpenCV classes.
org.opencv seems to import ok, but not any of the sub-packages or classes. In Android Studio it looks like this:
As I type out the package name, after org.opencv. the only suggestion is *.
What could I be doing wrong?
I have had this issue with Android Studio a couple of times
I find it is resolved by closing and reopening the project when the project reloads it has worked.
If that does not work try close and reopen Android studio.
The third thing you could try is |File|Invalidate Cache Restart| .
I have searched through Stack Overflow as I know this is a common question, but none of the solutions seemed to work for me. This included cleaning my project, deleting all imports and deleting the project and starting again entirely.
I am using the Eclipse specifically for android on mac (ADT bundle mac).
Whenever I create a new project I have errors immediatley in my src folder on the line
setContentView(R.layout.activity_main);
and also on inflate.
Any suggestions other than those stated? It is literally before I have done any programming so cannot understand what is wrong.
EDIT: Fixed. Downloaded the SDK a second time and this seems to have fixed it.
import The R class. The basic syntax is
import your_application_package_name.R;
If you have already imported it but it is not working then check if there in any error in your resource xmls. If so then r can be not generated and that error will be shown
Change your Project Build Target to the Latest
Right Click Project > Properties > Android > Change the Api to latest version
Try to update the Android_SDK. When you create or import a new Android project the SDk builds the project. The R problem is mostly an update SDK problem.
I'm trying to build Google's open-source Calendar app for Android (source here: https://github.com/android/platform_packages_apps_calendar), so that I may pick apart its code a little bit. When I import the freshly-cloned project into eclipse, I get a bunch of ____ cannot be resolved to a type errors. Looking closely at the types that aren't resolved, the root cause seems to be:
The import com.android.common cannot be resolved
The import com.android.ex cannot be resolved
I've been googling and I can't seem to figure out what's going on? I must be missing some library? I have everything in the Android SDK Manager installed, even the optional libraries. I've tried cleaning and fixing build path properties, etc. The errors remain.
Anyone have any idea what I can do to get this thing to compile?
I have managed to add almost all the required dependencies and now i got an almost-running version.
Kindly, check it out from here
You can also check the last commit, it contains all what i did to get this running version.
Have a nice day :)
I'm a beginner of Android Application development need to practice by examples and samples given in the book "Beginning with Android" by Wei Meng Lee, but whenever I try to follow those steps I come across a few errors unable to clean them. The Error seems like this:
" setContentView(R.layout.activity_main);" Don't know what type of error is it. In my computer I've installed SDK API level 16 that is for Android 4.1 What to do? Please guide me through appropriate answer.
Remove import
import android.R;
Than clean build your project also check xml layout file name in
setContentView(R.layout.activity_main);
than it'swork fine.
You should get the latest version of eclipse. Its now Eclipse Juno.
And check your import.
Remove
import android.R;
Instead put
import android.packagename.R;
If I make a new Android project in Ecplipse and I try, to open one of the samples from android SDK, I have got an error, look like this:
R cannot be resolved
What can I do, to be able, to run these files? I tried to delete import android.R; but nothing changed.
Thanks
First thing you might try is "clean" your project (option in the menu). If it persists:
There should be an error that stops R from being generated. Check the "problems" tab (?) in eclipse to see what that problem is, and solve that. It could be missing libs, or various other stuff.
You possibly got error in building resources.
Possible fixes:
-refresh your project (F5)
-clean you project and refresh
-see "Console" tab, sometimes the problem is shown there
-reload the Android SDK
-restart the Eclipse IDE
Check your XML-Layout files. The problem come here half a time.
If you are sure it is note your layout file, check in your java build path if the google librarys are well set. (Google APIs)
(sorry for my bad english)