R.layout.menu cannot be resolved

Question

Everything was working fine earlier. I then happened to add a new xml file to my layouts. now, one of my classes is giving an error when setContentView points to (R.layout.menu). Eclipse is telling me that R.layout.menu cannot be resolved. I can't figure out why; I have a layout called menu defined in my layout folder.

Any suggestions?

Answer 1

Did you do a Project > Clean? Sometimes you just have to let Eclipse generate the R file again.

Answer 2

lowercase XML filename(not sure if this is a must)

check your androidmanifest if the activity(class file) is added over there

if my class file name is abc.class

my android manifest should have this line

<activity android:name=".abc"></activity>

Answer 3

请参阅R无法解决-Android错误

Answer 4

Also, check if you've imported android.R .

Delete that line, and your project should pull from its own R file.

Answer 5

This may not be your problem, but I had a nasty problem, related to Eclipse's tendency to snowball errors. I have an app with lots of graphics. I mistakenly saved one of the graphics in ny graphics editor as PSP type (Paint Shop Pro) but with a PNG extension. Because of this, I got the following errors:

[2010-12-21 13:49:04 - TSRemote] W/ResourceType( 4112): Bad XML block: no root element node found
[2010-12-21 13:49:04 - TSRemote] libpng error: Not a PNG file
[2010-12-21 13:49:04 - TSRemote] ERROR: Failure processing PNG image ...\android\TSRemote\res\drawable\reset_normal.png
[2010-12-21 13:49:04 - TSRemote] ...\android\TSRemote\res\layout\devices.xml:38: error: Error: No resource found that matches the given name (at 'src' with value '@drawable/deviceback').
(about 50 more of these -- one for every graphic).

Plus, in the IDE, every reference to R. was unresolved.

The key was the incorrect PNG file. Once I fixed that, all the other errors went away.

Answer 6

This happens sometimes.

Assuming that there are no errors in the xml files:

1 Make some harmless change in one in the xml files, like adding a string

2 Project > Clean

Repeat until it works.