Android: Import DrawerLayout cannot be resolved

问题:

I'm trying to import the classes required to use the new "Navigation Drawer" from Android http://developer.android.com/design/patterns/navigation-drawer.html#ImpactOnNav

DrawerLayout: http://developer.android.com/reference/android/support/v4/widget/DrawerLayout.html

ActionBarDrawerToggle: http://developer.android.com/reference/android/support/v4/app/ActionBarDrawerToggle.html

The import android.support.v4.widget.DrawerLayout cannot be resolved The import android.support.v4.app.ActionBarDrawerToggle cannot be resolved

I have updated the libraries to the latest version but still these classes are not recognized.

回答1:

How do I update the JARs in libs?

I usually do it by copying the file. You will find the JARs inside $ANDROID_SDK/extras/android/support, where $ANDROID_SDK is wherever your Android SDK is installed.

If you use Eclipse, if you copy this at the filesystem level, and Eclipse is open, press <F5> with the project highlighted in Package Manager so Eclipse picks up the changes. Easier is to drag it out of the SDK and drop the JAR into libs/ right in Eclipse, which will both update the filesystem and let Eclipse know about the change.

It's possible that the Eclipse option to add the JARs (right-click over the project, then choose Android Tools > Add Support Library... from the context menu) will also do this. That particular approach doesn't work for me due to some peculiarities with my development environment.

回答2:

Copy the support jar from the Android SDK into your libs folder. Should be in <ANDROID SDK FOLDER>\extras\android\compatibility\v13.

回答3:

In android studio, I found that adding dependencies solved the problem.

In the file menu find project structure. Under 'app', look for the dependencies tab. Click the green plus at the right hand side. Select library dependency.

I added both support-v4 and support-v13.