Iam using Jellybean. When i was putting layout name, this layout name is automatically created same as menu name. Then i access layout for main activity, i can't access id. I got error with main cannot resolved variable.
Code:
#Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_my_first);
}
#Override
public boolean onCreateOptionsMenu(Menu menu) {
getMenuInflater().inflate(R.menu.activity_my_first, menu);
return true;
}
I just recently ran into this problem as well.
It turned out that the generated name "activity_main" was not accepted. I removed the underscore and it worked. After I removed the _ underscore it was able to generate the R file.
Incidentally this was an error right from the originally generated code.
I had never seen this problem before.
Try cleaning your project!
Project - > Clean
Select "Build Automatically" so that every time you clean the project, it will be rebuilt. And yeah, make sure you are saving the file before cleaning it (I know it is weird but sometimes the errors refuse to go away until you save it and then Clean it). Make sure that there is no error in the files in the layout folder, as it sometimes prevents the auto-generation of the code in R.java
Also, make sure that your code in MainActivity.java does not have import android.R. Eclipse tends to add that when you are managing the imports.
Related
this is causing the error
public static final class id {
public static final int timeToSend=0x7f080021;
public static final int timeToSend,=0x7f080023;
}
whenever I remove the second and save the file eclipse changes it back. I tried changing it while eclipse is not running and yet when I opened eclipse it changed the file back. I don't have any duplicates in layout to cause the problem. I tried cleaning the project and it didn't work.
turns out I wrote android:layout_alignBottom="#+id/timeToSend," instead of android:layout_alignBottom="#+id/timeToSend" that's why it nade a duplicate with the comma. sorry for the trouble
Maybe it's because you have an XML element with the android:id="#+id/timeToSend," ?
Android ID's cannot have any special characters in them. So android:id="#+id/timeToSend, would be wrong due to the fact that it has a comma. All you have to do is find that ID and rename it.
It's not recommended to edit the R.java file because it generates itself based on all the ID's you have created. The only way to edit it is to get rid of the ID's that you have declared in XML, otherwise, every time you clean the project, they regenerate.
Something that I always try when R.java is giving me problems is rebuilding the project.
You should be able to find the option under Project and then Clean.
That's only if rebuilding it hasn't worked.
Good luck and I hope this helps!
I am having a hard time trying to get my way around this. I just started a new project, and without doing anything the project shows this error at the mainactivity.java src, right at this line...
setContentView(R.layout.activity_main);
gives me "R cannot be resolve to a variable", ok, "quick fixes" gives me among others the option to import R, I go ahead and do it, then I got a new error " activity_main cannot be resolved or is not a field" and then quick fixes gives me just one option, "change to activity_list_item", so my question is: why all this is happening?
and then on this method
public boolean onCreateOptionsMenu(Menu menu) {
// Inflate the menu; this adds items to the action bar if it is present.
getMenuInflater().inflate(R.menu.main, menu);
return true;
I get same error at R.menu.main, but now I do not get any options???
I am having a hard time with this R.java. I tried all possible fixes I found at this forum but none of them work.
help please. thanks
Sometimes, Eclipse will default to using android.R instead of com.your.package.R. Go to your imports section and check that you are importing your package's R file.
Then perform a directory refresh and a clean. This should fix your problem or expose another problem.
It could also be that you have cleaned your project and you have an error in some xml file, which will prevent R.java from being generated.
are you importing com.your.project.package.name and not com.actionbarsherlock for example ?
Remove import android.R; in your activity java file
I have just added an activity to my project (from the options) in eclipse called Dlg as a result a Dlg.java file was created along with a activity_dlg.xml. Also added the activity in the AndroidManifest.xml however eclipse has placed a small cross next to the Dlg.java file and activity_dlg has been underlined in
setContentView(R.layout.activity_dlg);
and it states activity_dlg cannot be resolved or is not a field. Why is this happening all of a sudden. I Added activites a while ago and they were fine.
Any suggestions ?
The "cannot be resolved or is not a field" error on the R class indicates that the changes you made (addition of the layout xml) is not reflected in the generated file. You can clean the project using menu Project -> Clean... to force re-generation of the R class.
It probably means that for whatever reason the R.java file, which is automatically generated, isn't generated or incomplete.
This usually means you have an error in your xml file.
Assuming that activity_dlg.xml actually exists, you probably have an error in there.
Maybe its referencing to an image or string which doesn't exists?
Open it up and check it carefully, not always does the xml reader underline errors.
If you can't find anything you can always try to clean your projects or restart eclipse, but that probably won't help.
I think the newly added activity_dlg.xml is not associated with an id in R.java file.
Confirm this by going to R.java. Under this you have something like:
public static final class layout {
public static final int activity_dlg=0x7f030000;//This is some id to your layout
}
If this is not present then u can right click on the project directory from eclipse and refresh. or Project->Clean to regenerate the R.java file.
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.
I just started playing around with android development, and already with just an attempt at making a button, I have encountered a problem.
The error I'm given in the following code is right on "R.id.button1".
It says id cannot be resolved or is not a field.
Do I need to manually reference every single object I make in the layout xml file? I found that this did work, but it does seem to be a bit much for every button I want to make...
package com.example.helloandroid;
import android.app.Activity;
import android.os.Bundle;
import android.view.View;
import android.view.View.OnClickListener;
import android.widget.Button;
public class HelloAndroid extends Activity {
/** Called when the activity is first created. */
private Button button1;
#Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.main);
button1 = (Button)findViewById(R.id.button1);
button1.setOnClickListener(new OnClickListener()
{
public void onClick(View v)
{
finish();
}
});
}
}
I've been wasting a lot of time (two weeks) because of the same problem until I discovered the problem wasn't mine but Eclipse's.
I guess there's a lot of people with the same problem.
Just try this: Save your project, close Eclipse and then open it again. So simple.
Do I need to manually reference every single object I make in the layout xml file
Yes, otherwise you won't be able to do anything with those views. It's not that bad actually. So, each time you create a view in your XML, and you want to reference it, put an ID:
<View
android:id="#+id/the_id"/>
And then, from your code you can reference it using the R class. You can type, in the example, R.id.the_id and then Ctrl+Shift+O to make Eclipse auto import the needed files.
You can speed up your productivity by using frameworks like Roboguice; I think it's for lazy people, though.
This answer is not applicable to this question (looking at code you have provided). Just adding it if someone else stumbles here and above mentioned answers do not help.
If cleaning (Project --> clean) doesn't helps or saving and restarting eclipse doesn't help either, check for the following incorrect import.
import android.R;
Which Eclipse sometimes add by mistake on auto-import (Ctrl+Shift+O).
Remove that line (import) and it's done :D
Following this EXCELLENT tutorial , I encountered the same problem. After reading Carmello's answer (Sept 17, 2011. 07:23) I simply clicked File->Save All, and voila, 'button0' was automagically defined, and even syntax highlighted.
If "R.id.button1" is not defined, then you'll get a compile error, just as you saw. If you don't define this in the layout, then it won't be defined.
You don't have to specify every object you create in the layout, but you do if you try to reference it from "R.*". You can manually create buttons and other objects that are not specified in the layout.
I ran through the same issues for time being. Plz, do not forget to define as follows:
<View
android:id="#+id/button1" />
if you are using the id in your .java class.
Button b =(Button) findViewById(R.id.button1);
Being said that, the id defined in xml file must match with the id in findViewById().
Go to the 'R.java' file under the 'gen' folder and check whether your 'button1' is present under the class 'id'.If not,then this could be the reason you got that error.When you use the statement " R.id. " make sure that the is present under the appropriate class,in this case under the 'id' class.
R.id is a generated object that assigns int numbers to resources. Try this go to your gen/mypackage/R.java and delete the file. As you can see it is re-generated. This file provides static references where as the context is more of the dynamic state of your app. If you have syntax errors that will prevent automatic re-generation of that R.java file so you will get lots or R. errors. As everyone else has said you can click save all icon or ctl+shift+s on windows. You can clean the project project/clean and that will clean up 95% of those exceptions. Yes eclipse is buggy that way but netbeans does not support android that well. this link may help
Good luck
Do these things,anyone of this will help you
Project -> Clean,
Right click -> Fix Project Properties
Restart Eclipse
make some fake modification in manifest and save
check your console for any error message
check your drawable folder, check the image names satisfy the rules