Android - R cannot be resolved to a variable [dupl

2019-01-04 08:37发布

Possible Duplicate:
R cannot be resolved - Android error

I am having a issue which I have had before and I don't understand the cause. My project and code is fine as it was running yesterday. I have open Eclipse today and the whole project looks like it contains errors.

I believe it is some sort of build path issue. I don't understand why it randomly occurs? But in the code where there is R.Layout.LayoutName there is an issue... can anyone help?

I have tried cleaning and building it, I have tried importing android.R but I didn't have this before, it then gives and error and says the layout file doesn't exist.

8条回答
We Are One
2楼-- · 2019-01-04 08:58

You want Clean Project Like this

click on

Projects>Clean>select your project

this will help to u

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Ridiculous、
3楼-- · 2019-01-04 08:59

Save all layouts, and replace them from the previous version. Start to copy one by one and clean the project everytime, sometimes one of the layouts has something, that eclipse doesn't like. It worked for me.

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Anthone
4楼-- · 2019-01-04 09:07

I think I found another solution to this question.

Go to Project > Properties > Java Build Path > tab [Order and Export] > Tick Android Version Checkbox enter image description here Then if your workspace does not build automatically…

Properties again > Build Project enter image description here

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我命由我不由天
5楼-- · 2019-01-04 09:09

Are you targeting the android.R or the one in your own project?

Are you sure your own R.java file is generated? Mistakes in your xml views could cause the R.java not to be generated. Go through your view files and make sure all the xml is right!

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欢心
6楼-- · 2019-01-04 09:09

I've fixed the problem in my case very easy:
go to Build- Path->Configure Build Path->Order and Export and ensure that <project name>/gen folder is above <project name>/src
After fixing the order the error disappears.

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Deceive 欺骗
7楼-- · 2019-01-04 09:11

check your R directory ...sometimes if a file name is not all lower case and has special characters you can get this error. Im using eclipse and it only accepts file names a-z0-9_.

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