Develop Reference

Cannot find Log class in Android

I am developing an app in Android Studio with target for API 22. I have tried to use the Log class with the method d() but I did not find it. The helper shows only Log()...
What am I missing?

Just import the library import android.util.Log;
And just tips: use alt+space and alt+enter feature from Android Studio
Note:
Alt + Enter = Project quick fix (show intention actions and quick fixes)

The setContentView(R.layout.activity_main); is not working

My activity_main.xml gives me an error which says activity_main cannot be resolved or is not a field
setContentView(R.layout.activity_main);
I did Android 2.2 while unchecking the x on "Create Activity" so everything was empty and I had to fill it!

On your project explorer
click on resources,then
click on layout,then
you see a "file_name.xml" if not rename it to "file_name.xml" by pressing F2 ,
then replace
setContentView(R.layout.activity_main);
with
setContentView(R.layout."file_name");
dont forget to add
import "YOUR_PACKAGE_NAME".R;
above class decleration

It looks like u have imported android.R instead of that you import your package name else make it as
setContentView(packgname.R.layout.activity_main);

If you are importing
import android.R;
remove this line and then press ctrl+shift+o(for import necessary packages R file)

Your eclipse IDE
Porject---->clean>Build Automatically
Import packagename.R
by pressing ctr+shift+o

Cannot get reference to layouts and id in res. folder

This question has been up a couple of times but still I haven't found an answer that helped me.
1:st one:
I cannot find any of my R.Layout.activity_article_detail and other layout xml files through reference. It stopped working after did a "clean project" in Eclipse and tried to build it up again.
I've tried removing and adding and removing the .R import but right now it wont find any of them. My layout files doesn't include a Capital letter, are spelled correcly.
code:
package martin.larsson.kopingsrssreader;
import android.content.Intent;
import android.os.Bundle;
import android.support.v4.app.FragmentActivity;
import android.support.v4.app.NavUtils;
import android.view.MenuItem;
import martin.larsson.kopingsrssreader.R;
public class ArticleDetailActivity extends FragmentActivity {
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_article_detail);
Second problem is it cant find my res.menu either. I got 2 files in it. detailmenu.xml and refreshmenu.xml. In both i cant find any of the id tags
<item android:id="#+id/actionbar_markunread"
<item android:id="#+id/actionbar_saveoffline"
<item android:id="#+id/actionbar_refresh"
Does anyone got a clue?
SOLUTION: Uncheck "build automatically" and do a "clean project", and a Eclipse restart.

Clean your project or restart the eclipse.
Look to the imports, the R imported maybe is not correct.
If anything is wrong in your layouts, new updates aren't added to the R file. Look at the errors panel, and possibly to a clean rebuild to see what errors are popping up.

if u have an error in any of the resource files R will show up red unless all Errors are fixed and the project is built

how to import Android-DirectoryChooser

i'm triing to use this directory picker: Android-DirectoryChooser
if i import it in eclipse like: file -> import -> existing and. proj. -> directory picker -> library and sample project
it gives this errors:
what am i doing wrong?or how to implement it in the right way?
errors:
The declared package "net.rdrei.android.dirchooser" does not match the expected package "main.java.net.rdrei.android.dirchooser"

Change the package name at top of the class ,It is the starting statement of your class and your own package ,where your getting the error right click on that you will have your own package...

Android Wheel Data picker

I want to use android wheel to choose from some items. I just downloaded some library code from google. I am using it in my app, but it is giving some error.
import kankan.wheel.widget.OnWheelChangedListener;
import kankan.wheel.widget.OnWheelScrollListener;
import kankan.wheel.widget.WheelView;
import kankan.wheel.widget.adapters.AbstractWheelTextAdapter;
import kankan.wheel.widget.adapters.ArrayWheelAdapter;
Giving following error:
The import kankan.wheel.widget cannot be resolved
Can anyone tell me why this error is coming.
Thanks.

I have also used that library in my code and it is working fine.
possibility of error
You can't configure lib properly
In build path add lib
Clean eclipse.
Restart eclipse
import kankan.wheel.widget.OnWheelChangedListener;
import kankan.wheel.widget.OnWheelScrollListener;
import kankan.wheel.widget.WheelView;
import kankan.wheel.widget.adapters.NumericWheelAdapter;
WheelView wheel = getWheel(id);