R.java is not generated. I tried several strategies like cleaning and building etc, none of them seemed to work. Please dont mark this as duplicate since I have tried all the strategies that has been told in other questions.
A common problem with not generating the R file is that you have an error somewhere in your code. Something doesn't match, isn't imported, etc. The R file isn't built until your code can be compiled without errors, even though sometimes it does anyway. I can't give you a reason why it does that, but make sure you don't have errors.
Go to the bottom of your eclipse view and look for a tab that says "Console". It may just show you that youve declared something in one of your layouts that doesnt make sense to the compiler or something like that. Also check the error log and the problems tab.
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This is the image of my main_avtivity:
This is the image of my activity_main.xml layout:
I have imported com.example.calculator.R class. I even tried to clean the project so many times. I even made a new Project two times. Moreover my ADT Plugin is properly installed. Plz help me. I have done everything mentioned in other StackOverflow answers but nothing seems to be working for me.
R.java won't generate properly if there are errors in your XML files. So look through your XML files and look for any possible issues. The errors in the console at the bottom of your second screenshot would be a good place to start.
First SaveAll your changes then go to project>Clean Project and Build it again. Its seems like you didn't save your project.
So I've been working on projects for my class and I had a small error in an extra instance I was calling. I hit clean to see if it would clear it out and instead it created errors on all of my buttons and all of my toasts. It now says they all cannot be resolved or are not fields. They were all working fine until I had hit clean as I had tested everything right before doing so. Has anyone else had this occur?
I know it sounds weird, but this occurs when there is an error in one of the .XML layouts, no matter Eclipse is not detecting it. Please check any recent changes in XMLs and clean again.
I created an app which runs without any problem
But it contains lot of warnings
Here my question?
What problem will arise when app contains a warning
Thanks in advance
I usually use the warnings to clean up my code in the following manner:
They tell us which variables are never used locally. Hence, DELETE them.
Use of deprecated stuff in android, hence keeping my code up-to-date.
Removing unused imports.
Useless assignments to variables.
Errors in Manifest like not setting "allowBackup=true/false"
etc etc...
No errors, but only warnings, means your code will run well. But the code may not be the best.
The difference in an error and a warning is that an error doesn't allow the code to be compiled. A warning on the other hand is a message from the compiler telling that you have something weird or unnatural in your code, but it's still able to compile.
A warning should be interpreted as "this is weird, but if you know what you're doing, then it's OK".
For example, pointer casting (from one object type to another object type) is a common source of warnings, but if you know what you're doing and you're confident it will not fail, you can ignore it.
Warnings are not errors, and as others have said, if you know what you are doing you can ignore them. But remember that warnings are the compiler trying to help you, and programming can be difficult enough that you should be grateful for any help you can get. A good way can be to ignore only those warnings that you know exactly what they are caused by, and be very suspicious of any others. And always try to get rid of all the warnings, so the important ones don't get lost among all the unimportant ones.
Warnings are only indicators that there's something wrong, but this something isn't critical for running your app. Sometimes it's just that an imported code isn't used at all, another time it's a hint that a code can throw a NullPointer that you aren't catching right now. But summing up, warnings are not critical - at least during development time.
So far, you should only care about the errors that will prevent you from compiling your app.
It depends upon the types of warnings you have. If you have Deprecated Warnings then
You can configure the Java Compiler to ignore the Deprecated Warnings. I'd suggest to configure this setting for the specific project, not globally. To do so, right-click on your project and go to Properties > Java Compiler > Errors/Warnings. Click Enable project specific settings and then unfold Deprecated and restricted API and select Ignore for Deprecated API.
This will disable all deprecated warnings though.
So I've been working on this project all day, and no problems. I add an id to a layout element in one xml file, which is not being recognized by the IDE (all other IDs are, but this one isn't). I've run into things like this before over the past couple days, and a "Project > Clean" usually fixed it. So I did so - and virtually every one of my files that references R.anything comes up with the red X - I look and see that R.java isn't being created.
I searched SO and found a couple solutions about turning on or off "Build Automatically" and tried that - no luck - someone else said try setting target to 2.2 - tried that, no luck. Tried deleting it manually, tried recreating it and adding it as source - no good. Restarted eclipse, and tried everything again, without success.
As I said, I must have compiled this thing 100 times tonight, and the only change I made between working fine and failing is adding an id to an element (which I've since removed).
If you have a corrupt XML-file and try to rebuild your R.* it will fail. You should go through your xml-files and make sure that they are all error-free. It's likely you have a misspelling or other small problem somewhere that prevents the build.
This is a really stupid question I imagine, but is there a way to search for hidden errors. I'm working on a project in MotoDev's Eclipse environment, and it won't let me run suddenly stating that I need to fix errors first, but it won't show any errors in the log at all.
Check out the Problem view, you may get something there.
There shouldn't be any hidden errors in MOTODEV Studio. As Tony mentions, bring up the Problem view to see if there are any errors listed there. Also, look in the project explorer and see if there are any files or folders with a red X on them, which indicates a file with a problem is in there. Failing that, do a clean build on the project.
If the problems persist, give us a shout on the MOTODEV forums and we'll work with you to get the issue resolved.
Eric