When I create a new android project (following these steps: http://developer.android.com/training/basics/firstapp/creating-project.html) I automatically get syntax errors and I don't get it. I have attached a photo of the problem. Please help. I downloaded everything I needed to and in the older versions of this, everything worked fine.
You are importing the wrong R. You should be doing
import com.chatnexttofriends.R;
instead of
import com.android.R;
This could have happened if you used the Organize Imports option before the automatically generated files where created, or because there was an error in your resources that prevented the automatically generated files from being created.
If you intend to use resources from both Rs, then you will have to fully qualify one of them. I would suggest qualifying Android's R. I.e.:
setContentView(android.R.layout.activity_list_item);
Although I doubt you want to set the content of your Activity to that of an item representing an Activity in a ListView.
Related
I'm having a lot of doubts and after two days of searching I still haven't found a good answer for my problem.
I have an app's project that is already in the store and this project have lots of Activities, Fragments, Services, IntentServices, Layouts, and resources (images, strings, integers, colors, styles, raws, drawables, etc...).
Now, I need to implement a new app that is almost a copy of the first one where I need only to change the background, some resources (but almost 99% stay the same), and maybe in one or two fragments I'll need to change some code (implement different logic statements).
I decided and I think it's natural to convert the all project in an library project.
I did:
1º Create a new project called framework and configured as library. Copied all code and resources (with the exception of assets folder) from the original project to here.
2º In the original project I leave only the manifest, proguard file. I change the manifest and proguard file to reference the classes of the new library.
I tested the app to see if was still working and it was Ok. Until now I did only the separation.
Now, came the problem. I need to create a solution reusable,and scalar for the library that allows me to use it in different apps.
In my original project I created a subclass of Application class that I use for global variables.
Without any others ideas, I decided the following:
1º Convert my MyApplication class in an abstract class. Also, I create an interface ApplicationInterface with some methods like isBackgroundOverlayed() or getBackgroundResource() that I use in the fragments to change the backgrounds or any other logic from the originally defined.
2º In the App's project, I created a new Application class that extends the abstract class MyApplication and implements the interface ApplicationInterface and which is declared in the Application tag in the manifest file.
Conclusion: This all works and I was able to have two app's projects with different background and other images like logos and even change some code logic. An example is in the original App when the user press one certain button, the App shows a dialog choice. In the new app when the user press the button it execute one fragment (without choice).
My concerns: I don't feel this is the best solution for the problem or best practice or good "pattern".
Do you have any ideas?
Thank you in advance!
ps: Sorry if I haven't use this forum properly. I search for an answer but I didn't found any.
I think you have achieved what you wanted, but that was a lengthy and time consuming process. One more thing I would like to mention is you should not change library projects for different applications
As said on Android developers guide :
Library projects contain shareable Android source code and resources that you can reference in Android projects. This is useful when you have common code that you want to reuse.
you can read more from here
Also you have to figure out,which lib is doing which work in case you forget what changes you have made
I would suggest you to keep a separate copy of original project and then import it into new work space in Eclipse (by checking copy project into current work space so that you have a new copy of your project) and consider changing its package name to get a new project
you can refer ans on this link to see how to change package name`
I've downloaded the ContactsList example from google's developer site. When creating a new project with this code, I've got several errors, and I realized that all are because the same thing: It doesn't get the R resources, so it is importing the android.R.
I've tryed celaning the project, trying to solve layout's issues if the had, etc.. but still doesn't create the R.java file in "gen".
So, I don't know what I'm forgoting to do because I tought that code downloaded directly from google should work fine.
Check for the following:
Check whether there is error in your xml file.
Check whether you are missing any jar(additional) file.
Try to change your target sdk to some other and change to original.
An excerpt from the documentation :
Eclipse sometimes likes to add an import android.R statement at the
top of your files that use resources, especially when you ask eclipse
to sort or otherwise manage imports. This will cause your make to
break. Look out for these erroneous import statements and delete them.
My question : WHY? Why does eclipse keep on doing this?
I have been developing Android applications using Eclipse for a quite some time now but I have never been able to understand why eclipse does such a thing.
When I use Ctrl + Shift + O to organize my import statements, import android.R gets added automatically. And all of a sudden my correct code is suddenly covered in red errors, saying that R cannot be resolved. It can get really scary for a beginner as he has no idea what he did wrong.
In another scenario, suppose there is something wrong with my layout files and R.java is not being generated, it says that R cannot be resolved, as R.java has not been generated due to the errors. As I move my cursor to any of the errors, it suggests me to import android.R.
After working on Android for quite sometime now, I know that never to import android.R, but what I have never been able to understand why eclipse keeps on suggesting it, as frankly speaking, adding import android.R never solved any problem of mine. It just added to the existing problems, which used to be really painful during initial days of development.
So, does anyone know the reason behind eclipse making the suggestion to make an incorrect import? Is it just a bug? I don't think it's a bug, as it would have got fixed at least after it was mentioned on the Android documentation.
If it's not a bug, then what is a real purpose of android.R? What does it exactly refer to?
Your opinions/experiences will be really helpful!
Thanks!
This is not a bug. There are a few instances where android.R can be helpful and solve problems.
android.R is an R.java file like the one you have in your own projects. The one in your projects (your.packagename.R) holds references to the resources you have under your /res folder like layouts, drawables, XML files, raw files, strings etc.
On the other hand, the android.R file holds references to certain default resources that Android has inbuilt, like simple_list_item_1.
Eclipse suggests this and auto imports this sometimes as if your project's R file hasn't been generated due to an XML error or something, your code will be referencing a file that doesn't exist. By importing android.R, eclipse makes sure your code references a class that exists. However, android.R is unlikely to have the same resources you did, and this will raise another set of errors.
Eclipse will also always try to automatically import android.R in your class if you rename your package name via android tools and not rename base package name in your code with the same name because he will assume you have two R's in your file.
Try this...
Window -> Prefs -> Java -> Editor -> Save Actions
Uncheck "Organize Imports." Hopefully that will do it.
After this setting, it works for me.
I added some UI elements to the main.xml file in the res\layout folder and when I try to access them through the call, R.layout.my_uielement, the UI element that I created is not there. Even when I add a new xml file with UI elements, it still doesn't show up in the R.layout class. I have made checked the ids on them and they have the correct format (I think): android:id="#+id/my_button". What could be the problem? Do I need to compile the code first?
UPDATE:
I have already tried adb kill-server then adb start-server. It doesn't seem to help. I have also tried R.id.my_uielement, it doesn't register either.
This may not be the case for you, but sometimes when I use something from the android.R package (default android resources) and I use it in my class before making reference to anything from my own resource package, Eclipse adds the import android.R; statement in my imports. This will conflict with the default behavior of implicitly looking in your package's resources.
Check your import statements for import Android.R;. If it's there, remove it. And, if you're using anything from android.R, fully qualify it when you use it in code.
Clean project works fine. In Eclipse if you just change some xml components, it doesn't always generate a new R file. Cleaning does it.
Use R.id.your_ui_element, not R.layout.your_element
I faced this problem too. The R.java was neither generated nor updated.
If R.java is not generated when you create the project, run your 'empty` project. An R.java with references to resources will be automatically generated.
If R.java is not getting updated, Check for updates in Help -> Check for Updates
in Eclipse and update your SDK and ADT if required.
After 2 days I found a way to fix it...
I had saved half done project in my mail, so when R.java vanished i just replaced it with the old R.java file, this fixed a lot of errors, then made necessary changes and built the project(build it not clean)...I do not know whether clean and build performs the same job or not..but everytime i cleaned it , R.java used to go invisible...
Clean is working because it BUILD the project after cleaning. So the problem is ( at least it was in my case, because I switched off the Automatic Build a few days earlier ) that after you add an item or anything in a .xml file, the eclipse doesn't build it and can't refresh the R.java .
I've noticed that my R.java file is not always being properly updated when I add items to my strings.xml file or elsewhere. If I use a new value I added like R.string.newString the actual integer value might still be pointing to R.string.oldString or whatever (it seems to usually be the element directly above or below the new element in strings.xml but I haven't nailed down the pattern for sure yet).
You're not supposed to modify the R.java file, but it doesn't say anything about deleting it (not that I've seen, anyway). I've found that deleting R.java usually fixes my resource-related problems because Eclipse immediately regenerates the file with the integer values properly assigned.
Please note, I'm very much a beginner at Eclipse so I may not understand the consequences of deleting R.java but it seems to be working well for me so far. If what I'm doing is very bad, please let me know.
None of these worked for me!
The only way i can access an #+id/foo is by myPackage.R.id.foo.
When I add drawable resources to my project they do not show up in the list of drawables in the Reference Chooser. I checked the R file and there are references for the files.
I have tried refreshing the project, cleaning the project, and fixing project properties and nothing seems to help. Sometimes a couple will randomly show up in there, but not all of them.
The only consistent way I can get them to show up is to restart Eclipse.
Any ideas?
Thanks
Edit: Further findings:
After some trials, I found an other inconvenient work around to he issue. Turns out when importing multiple files into the project at once, Eclipse will only add the last one imported into the reference chooser. So when I imported my images one at a time, they all show up properly!
Like I said, inconvenient considering the amount of images I have left to import, but maybe with this new information it may help nail down where the issue may be and a possible fix.
I too faced the same problem. I added an image to the res/drawable-hdpi folder, cleaned the project and was able to see the name of the image in the left pane in Eclipse. But when I tried to use this image using Reference Chooser and looked under Drawable, I didn't find it.
I simply exited from Eclipse, and started it again. It was there! Like many things in computers, problems can be resolved simply by restarting!
The only way I found to fix this is to include the generated R class itself.
I found out some new info again.
Since I am doing a port from Blackberry, almost all of my images' filenames have uppercase letters in them, so I end up importing them all and then having to rename all the images after they are imported into the project.
I tried renaming all of my images before importing them all into the project. To my delight, all of the images showed up right away in the reference chooser! So it seems there is a problem when you import files and they cause errors with your project and allowing all of them to show up in the reference chooser.
So if you have to rename files, do it before import!
I'm just not entirely sure that this is the only cause for this issue but it has solved the problem for me.