title: Using an Android library project Activity within another project
body: <p>I have an Android library project that I would like to use from within another Android project.</p>
  
  <p>The library has a Activity declared in its AndroidManifest.  When I try the following within the second project:</p>
  
  <pre><code>        Intent intent = new Intent(this, ReaderActivity.class);
          startActivity(intent);
  </code></pre>
  
  <p>I get the following exception:</p>
  
  <pre><code> java.lang.RuntimeException: Unable to start activity ComponentInfo{br.com.digitalpages.reader.demo/br.com.digitalpages.reader.demo.ReaderDemoActivity}: android.content.ActivityNotFoundException: Unable to find explicit activity class {br.com.digitalpages.reader.demo/br.com.digitalpages.reader.ReaderActivity}; have you declared this activity in your AndroidManifest.xml?
       at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2663)
  ...
   Caused by: android.content.ActivityNotFoundException: Unable to find explicit activity class {br.com.digitalpages.reader.demo/br.com.digitalpages.reader.ReaderActivity}; have you declared this activity in your AndroidManifest.xml?
       at android.app.Instrumentation.checkStartActivityResult(Instrumentation.java:1404)
       at android.app.Instrumentation.execStartActivity(Instrumentation.java:1378)
  ...
  </code></pre>
  
  <p>How can I open the Activity from the another project?</p>
  
  <p>EDIT:
  By users answers I added the following line into my second project</p>
  
  <pre><code>&lt;uses-library android:name="br.com.digitalpages.reader" android:required="true" /&gt;
  </code></pre>
  
  <p>But it's still doesn't works</p>