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I keep getting this error. Should I just make id a field?
My code is:
public void onCreate(Bundle icicle)
{
super.onCreate(icicle);
setContentView(R.layout.main);
ImageView mainimage = (ImageView) findViewById(R.id.mainanim);
mainimage.setBackgroundResource(R.anim.mainanim);
mainanimation = (AnimationDrawable) mainimage.getBackground();
}
How exactly do you fix this?
Look at your import statements at the top. If you are saying import android.R, then there that is a problem. It might not be the only one as these 'R' errors can be tricky, but it would definitely definitely at least part of the problem.
If that doesn't fix it, make sure your eclipse plugin(ADT) and your android SDK are fully up to date, remove the project from the emulator/phone by manually deleting it from the OS, and clean the project (Launch Eclipse->Project->Clean...). Sounds silly to make sure your stuff is fully up to date, but the earlier versions of the ADT and SDK has a lot of annoying bugs related to the R files that have since been cleared up.
Just FYI, the stuff that shows up in the R class is generated from the stuff in your project res (aka resources) folder. The R class allows you to reference a resource (such as an image or a string) without having to do file operations all over the place. It does other stuff too, but that's for another answer. Android OS uses a similar scheme - it has a resources folder and the class android.R is the way to access stuff in the android resources folder. The problem arises when in a single class you are using both your own resources, and standard android resources. Normally you can say import at the top, and then reference a class just using the last bit of the name (for example, import java.util.List allows you to just write List in your class and the compiler knows you mean java.util.List). When you need to use two classes that are named the same thing, as is the case with the auto-generated R class, then you can import one of them and you have to fully qualify the other one whenever you want to mean it. Typically I import the R file for my project, and then just say android.R.whatever when I want an android resource.
Also, to reiterate Andy, don't modify the R file automatically. That's not how it's meant to be used.
Do not modify the R class. The error means there's something syntactically wrong with your XML layouts and R cannot be auto-generated. Try looking there and post the xml code you're not sure about, if any.
Edit : also: remove "import android.R" from imports at top of file (if there)
One possible solution:-
Summary: make sure you are using import com.yourpkgdomainname.yourpkgappname.R instead of import android.R
Details: The problem occured when I changed ID of a label which was being referred in other places in the layout XML file. Due to this error, the R file stopped generating at first. Eclipse is bad in handling errors with the layout files.
When I corrected the ID reference (with project clean few times and Eclipse restarts, I noticed that my import packages now has:
import android.R
Changing it to following fixed the error:
import com.example.app.R
I just fixed my problem right-clicking in the layout folder and clicking in the option Validate. Some windows will appear, you just clik OK and ist fine.
May be you created a new xml file in Layout Directory that file name containing a Capital Letter which is not allowed in xml file under Layout Directory.
Hope this help.
Just throwing this out there, but try retyping things manually. There's a chance that your quotation marks are the "wrong" ones as there's a similar unicode character which looks similar but is NOT a quotation mark.
If you copy/pasted the code snippits off a website, that might be your problem.
As Jake has mentioned, the problem might be because of copy/paste code.
Check the main.xml under res/layout. If there is no id field in that then you have a problem.
A typical example would be as below
<com.androidplot.xy.XYPlot
android:id="#+id/mySimpleXYPlot"
android:layout_width="fill_parent"
android:layout_height="fill_parent"
android:layout_marginTop="10px"
android:layout_marginLeft="20px"
android:layout_marginRight="20px"
title="A Simple Example"
/>
Some times eclipse may confuse with other projects in the same directory.
Just change package name (don't forget to change in Android manifest file also), ensure the package name is not used already in the directory. It may work.
Just came across this myself.
Finally found my issue was with a .png file that I added that had a capital letter in it an caused exactly the same problem. Eclipse never flagged the file until I closed it and opened Eclipse back up.
What seems to be the problem, I just fixed mine in case anyone was wondering - Due to other errors i turned off build automatically, when i created a new project it said R.layout.main had an issue and needed to import R; So naturally as a novice, i did. Then i built manually and it had a problem with main. Try building your program as is, remove import R and it should be fine.
In main.xml (or wherever your item is defined) make sure that the ID for the R item is defined with #+id/... Here is an example with a button:
<Button android:text="B1" android:id="#+id/button_one"
android:layout_gravity="center_horizontal|center"
android:layout_height="fill_parent" android:layout_width="wrap_content" />
Each of these is important because:
# must precede the string
+ indicates it will create if not existing (whatever your item is)
I also had this error when I was working in a Java class once. My problem was simply that my xml file, with the references in it, was not saved. If you have both the xml file and java class open in tabs, check to make sure the xml file name in the tab doesn't have a * by it.
Hope this helps.
Just Clean your project so R will be generated automatically. This worked for me.
It gave me enough pain but I found the solution:
PROJECT ---> Clean ----> (Sele)
I had this problem but in my case it solved by restarting the eclipse.
For me the cause of the problem was that I had 2 images with the same name in my drawable-hdpi folder. Once I resolved that, then the R.java rebuilt itself and the problem was automatically solved.
select Project tab and click Build automatically so Build all option will be activated and then click on build all.and always start xml file name with lowercase.
Just added a new button to my already-working-fine layout, but the findViewById function seems to be angry with something I don't get to understand.
Here's a bit of the layout:
<LinearLayout
...
>
<ListView
android:id="#+id/my_lovely_list"
android:layout_width="fill_parent"
android:layout_weight="1"
/>
<Button
android:id="#+id/my_lovely_butt"
android:layout_width="fill_parent"
android:layout_height="wrap_content"
android:text="#string/exit_b"
android:layout_weight="0"
android:clickable="true"
/>
</LinearLayout>
And here's a bit of the coding:
#Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.main);
...
list_o = (ListView)findViewById(R.id.my_lovely_list);
butt_o = (Button)findViewById(R.id.my_lovely_butt);
...
}
So, the big mistery is that the ListView is found without any problem, but the Button won't by any means. I've already tried cleaning the Proyect, and look throught the posts I've found here... but still don't get to find the problem! Any thoughts?
import yourpackagename.R;
instead of android.R;
import R of your package
Also Clean your project that will refresh your entire project then you will also find ID of button also
Some times the file R is not regenetated. Try :
Clean your project
Rebuild it
Manage to go back to a version that compiled and retry adding your elements one by one and compile each time to check the R file
Finnally the last option is to close/reopen eclipse yep some bugs can't be overcome other way ^^"
No worry that's is just some common eclipse/android bug it happen often (Well some other times it can also be a small syntax error somewhere in your project but i assume that you already checked that x)
Good luck
Clean your project in Eclipse.
Make sure the id is not duplicated
Remove the button, save and add the button again and build the code.
Make sure the correct R file is imported.
If its a syntax related problem, then its got to do with compile time stuff.
If its a problem when the code executes, make sure the layout is inflated. If the listview is found, then the button also must definitely be found.
Make sure to go through these processes.
1: Make sure you imported your project R file.
import packagename.R
2: Clean your project
3: If the above two solutions doesn't work, do invalidate your cache and restart
In Android Studio Build -> Clean Project resolved the problem for me.
while, just by clean you project, rebuild it, or import the R file manually, it might a sad thing to find the id of specified view component still cannot find by the activity.
and then, if you check the detailed content of the R file, you will find the id has not
generate, and then, what you need to check, if there are something wrong with your own /res
file, for example, the name of the layout file, drawable file name, or the variant name of the menu file .etc.
all of these could just make the R file cannot generate correctly, or even worse, the R file
does not generate out at all.
How do I fix this? I already tried removing the R.java and cleaning the project via eclipse, but it doesn't help.
FYI I am trying to get PhotoStream from here: http://code.google.com/p/apps-for-android/, but so far it has been very difficult to get things work.
Okay..... 5 mins later google tells me the correct answer...
http://www.fairtec.at/en/it-blog-mainmenu-16/168-the-type-r-is-already-defined
I just didnt search hard enough.
"The type R is already defined"
That's the message you get in Eclipse if you try to build the Funambol Android Sync Client.
Reason is that you have checked two Builders that try to generate the same class.
You just have to uncheck the Java-Builder from Project->Properties->Builders.
Then the application even works fine in the Emulator.
Delete the R.java from the src folder and rebuild the project. This file will be automatically rebuit during this process.
http://www.fairtec.at/en/it-blog-mainmenu-16/168-the-type-r-is-already-defined
click right to project click properties
Project->Properties->Builders.
unckeck java Builder
delete file R.java
You may want to change your package names. It looks like you are using a 'PhotoStream'.jar which has it's R.class defined at the same package structure as you.
Here is a link to the R.java from the project on Google Code. Notice you are using the same package:
http://code.google.com/p/apps-for-android/source/browse/trunk/Photostream/src/com/google/android/photostream/R.java?r=83
I had the same issue when I imported a project from work. Turning off the Java builder as suggested in the article you found fixed my problem, but when I made code updates they were not reflected in the running app. In my case there was an R.java in my source which I deleted and that fixed my problem.
In my case,
as i m not using any IDE for programming but using command line Android..
i had two xml files, one in layout and other in layout-land. i was using same id "XXX" for both but while declaring i made small mistake
android:id="#+id/XXX" (in layout xml)
android:id="#+id/XXX " (in layout-land xml)
please observe extra space in second id declaration, so while creating R.java they were different and in R.java i had
public static final int XXX=0x7f040046;
public static final int XXX =0x7f040045;
which are same, so please be aware of extra spaces. Thank you
I'm working through a book samples programs and i get the same problem whether I create and type the code or whether i download the code already typed, so i'm thinking it's a setup problem.
I get this error in each each class:
setContentView(R.layout.menu) where the "R" is underlined in red and the code won't compile. If i add import android.r like "QuickFix" suggests, the red line goes away from the "R", but then the red line appears under "menu" (in this example). The same behavior occurs in each of the 5 classes that make up the project.
I do have matching layouts for "menu" etc. And (to the best of my knowledge) I registered them as Application Nodes in the manifest file.
It's driving me nuts. Thanks for any suggestions.
You are not supposed to import android.R as it won't resolve your resources. Just remove that import and try to compile again.
If you are working off a tutorial then also check to have the same resources as in the tutorial and also if you decide to name thing different then keep that in mind an reference them by your names.
The R class is generated by Android and contains IDs for all resources in your res folder. Go to your AndroidManifest and locate the package= attribute on manifest. R is in this namespace. So if the namespace is com.yourpackage.blah, you'll want to import com.yourpackage.blah.R;
The problem was that for some reason Eclipse was not autogenerating the gen/R.java file. I don't know why. One time it did generate the file, and a after Project..Clean and Build All everything resolved. Thanks for the input.
Also make sure your file names under res, eg drawables, are OK. I had a file name with capital letter and that prevented the creation of R with the same reference errors that you got. I did not check the error messages and it took me a good 10-20 mns to find this out.
Sometimes this happens to me.
It usually happens that I have been working with some xml element, and before clicking to a java document to hit "run" i just hit "run" while on the xml. I don't really know what happens when you "run" an xml, but it makes this horible file called some_xml_name.out.xml.
DELETE THIS FILE!
This file is the reason why you get so many R related errors, since the Resources library is never really created, or something like that.
That is my advice, without actually seeing the error you're getting in the console.
I keep getting this error. Should I just make id a field?
My code is:
public void onCreate(Bundle icicle)
{
super.onCreate(icicle);
setContentView(R.layout.main);
ImageView mainimage = (ImageView) findViewById(R.id.mainanim);
mainimage.setBackgroundResource(R.anim.mainanim);
mainanimation = (AnimationDrawable) mainimage.getBackground();
}
How exactly do you fix this?
Look at your import statements at the top. If you are saying import android.R, then there that is a problem. It might not be the only one as these 'R' errors can be tricky, but it would definitely definitely at least part of the problem.
If that doesn't fix it, make sure your eclipse plugin(ADT) and your android SDK are fully up to date, remove the project from the emulator/phone by manually deleting it from the OS, and clean the project (Launch Eclipse->Project->Clean...). Sounds silly to make sure your stuff is fully up to date, but the earlier versions of the ADT and SDK has a lot of annoying bugs related to the R files that have since been cleared up.
Just FYI, the stuff that shows up in the R class is generated from the stuff in your project res (aka resources) folder. The R class allows you to reference a resource (such as an image or a string) without having to do file operations all over the place. It does other stuff too, but that's for another answer. Android OS uses a similar scheme - it has a resources folder and the class android.R is the way to access stuff in the android resources folder. The problem arises when in a single class you are using both your own resources, and standard android resources. Normally you can say import at the top, and then reference a class just using the last bit of the name (for example, import java.util.List allows you to just write List in your class and the compiler knows you mean java.util.List). When you need to use two classes that are named the same thing, as is the case with the auto-generated R class, then you can import one of them and you have to fully qualify the other one whenever you want to mean it. Typically I import the R file for my project, and then just say android.R.whatever when I want an android resource.
Also, to reiterate Andy, don't modify the R file automatically. That's not how it's meant to be used.
Do not modify the R class. The error means there's something syntactically wrong with your XML layouts and R cannot be auto-generated. Try looking there and post the xml code you're not sure about, if any.
Edit : also: remove "import android.R" from imports at top of file (if there)
One possible solution:-
Summary: make sure you are using import com.yourpkgdomainname.yourpkgappname.R instead of import android.R
Details: The problem occured when I changed ID of a label which was being referred in other places in the layout XML file. Due to this error, the R file stopped generating at first. Eclipse is bad in handling errors with the layout files.
When I corrected the ID reference (with project clean few times and Eclipse restarts, I noticed that my import packages now has:
import android.R
Changing it to following fixed the error:
import com.example.app.R
I just fixed my problem right-clicking in the layout folder and clicking in the option Validate. Some windows will appear, you just clik OK and ist fine.
May be you created a new xml file in Layout Directory that file name containing a Capital Letter which is not allowed in xml file under Layout Directory.
Hope this help.
Just throwing this out there, but try retyping things manually. There's a chance that your quotation marks are the "wrong" ones as there's a similar unicode character which looks similar but is NOT a quotation mark.
If you copy/pasted the code snippits off a website, that might be your problem.
As Jake has mentioned, the problem might be because of copy/paste code.
Check the main.xml under res/layout. If there is no id field in that then you have a problem.
A typical example would be as below
<com.androidplot.xy.XYPlot
android:id="#+id/mySimpleXYPlot"
android:layout_width="fill_parent"
android:layout_height="fill_parent"
android:layout_marginTop="10px"
android:layout_marginLeft="20px"
android:layout_marginRight="20px"
title="A Simple Example"
/>
Some times eclipse may confuse with other projects in the same directory.
Just change package name (don't forget to change in Android manifest file also), ensure the package name is not used already in the directory. It may work.
Just came across this myself.
Finally found my issue was with a .png file that I added that had a capital letter in it an caused exactly the same problem. Eclipse never flagged the file until I closed it and opened Eclipse back up.
What seems to be the problem, I just fixed mine in case anyone was wondering - Due to other errors i turned off build automatically, when i created a new project it said R.layout.main had an issue and needed to import R; So naturally as a novice, i did. Then i built manually and it had a problem with main. Try building your program as is, remove import R and it should be fine.
In main.xml (or wherever your item is defined) make sure that the ID for the R item is defined with #+id/... Here is an example with a button:
<Button android:text="B1" android:id="#+id/button_one"
android:layout_gravity="center_horizontal|center"
android:layout_height="fill_parent" android:layout_width="wrap_content" />
Each of these is important because:
# must precede the string
+ indicates it will create if not existing (whatever your item is)
I also had this error when I was working in a Java class once. My problem was simply that my xml file, with the references in it, was not saved. If you have both the xml file and java class open in tabs, check to make sure the xml file name in the tab doesn't have a * by it.
Hope this helps.
Just Clean your project so R will be generated automatically. This worked for me.
It gave me enough pain but I found the solution:
PROJECT ---> Clean ----> (Sele)
I had this problem but in my case it solved by restarting the eclipse.
For me the cause of the problem was that I had 2 images with the same name in my drawable-hdpi folder. Once I resolved that, then the R.java rebuilt itself and the problem was automatically solved.
select Project tab and click Build automatically so Build all option will be activated and then click on build all.and always start xml file name with lowercase.