title: android studio components not showing while designing activity
body: <p>Well I am new to android studio and when I created my first hello world app. I couldn't see hello world text-view. I dragged other components such as button and still nothing showed up in design or blueprints. But when I built hello world app. App showed hello world text-view in emulator. I have searched a lot in internet but couldn't find any solution.</p>
  
  <p>I have attached a screen shot below.</p>
  
  <p><img src="https://i.stack.imgur.com/wn2pY.png" alt="Screen shot after adding button in hello world activity">  </p>
  
  <p>Android Studio is generating following error:</p>
  
  <pre><code>java.lang.ClassNotFoundException: android.view.View$OnUnhandledKeyEventListener
  at org.jetbrains.android.uipreview.ModuleClassLoader.load(ModuleClassLoader.java:180)
  at com.android.tools.idea.rendering.RenderClassLoader.findClass(RenderClassLoader.java:61)
  at org.jetbrains.android.uipreview.ModuleClassLoader.findClass(ModuleClassLoader.java:118)
  at java.lang.ClassLoader.loadClass(ClassLoader.java:424)
  at java.lang.ClassLoader.loadClass(ClassLoader.java:357)
  at org.jetbrains.android.uipreview.ModuleClassLoader.loadClass(ModuleClassLoader.java:213)
  at android.support.v7.widget.ActionBarContainer.&lt;init&gt;(ActionBarContainer.java:62)
  at sun.reflect.NativeConstructorAccessorImpl.newInstance0(Native Method)
  at sun.reflect.NativeConstructorAccessorImpl.newInstance(NativeConstructorAccessorImpl.java:62)
  at sun.reflect.DelegatingConstructorAccessorImpl.newInstance(DelegatingConstructorAccessorImpl.java:45)
  at java.lang.reflect.Constructor.newInstance(Constructor.java:423)
  at org.jetbrains.android.uipreview.ViewLoader.createNewInstance(ViewLoader.java:481)
  at org.jetbrains.android.uipreview.ViewLoader.loadClass(ViewLoader.java:264)
  at org.jetbrains.android.uipreview.ViewLoader.loadView(ViewLoader.java:222)
  at com.android.tools.idea.rendering.LayoutlibCallbackImpl.loadView(LayoutlibCallbackImpl.java:209)
  at android.view.BridgeInflater.loadCustomView(BridgeInflater.java:337)
  at android.view.BridgeInflater.loadCustomView(BridgeInflater.java:348)
  at android.view.BridgeInflater.createViewFromTag(BridgeInflater.java:248)
  at android.view.LayoutInflater.createViewFromTag(LayoutInflater.java:730)
  at android.view.LayoutInflater.rInflate_Original(LayoutInflater.java:863)
  at android.view.LayoutInflater_Delegate.rInflate(LayoutInflater_Delegate.java:72)
  at android.view.LayoutInflater.rInflate(LayoutInflater.java:837)
  at android.view.LayoutInflater.rInflateChildren(LayoutInflater.java:824)
  at android.view.LayoutInflater.inflate(LayoutInflater.java:515)
  at android.view.LayoutInflater.inflate(LayoutInflater.java:423)
  at com.android.layoutlib.bridge.bars.BridgeActionBar.&lt;init&gt;(BridgeActionBar.java:89)
  at com.android.layoutlib.bridge.bars.AppCompatActionBar.&lt;init&gt;(AppCompatActionBar.java:68)
  at com.android.layoutlib.bridge.impl.Layout.createActionBar(Layout.java:277)
  at com.android.layoutlib.bridge.impl.Layout.&lt;init&gt;(Layout.java:161)
  at com.android.layoutlib.bridge.impl.RenderSessionImpl.inflate(RenderSessionImpl.java:288)
  at com.android.layoutlib.bridge.Bridge.createSession(Bridge.java:384)
  at com.android.tools.idea.layoutlib.LayoutLibrary.createSession(LayoutLibrary.java:193)
  at com.android.tools.idea.rendering.RenderTask.createRenderSession(RenderTask.java:544)
  at com.android.tools.idea.rendering.RenderTask.lambda$inflate$3(RenderTask.java:678)
  at java.util.concurrent.FutureTask.run(FutureTask.java:266)
  at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1142)
  at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:617)
  at java.lang.Thread.run(Thread.java:745)
  </code></pre>
  
  <p>and here is the screenshot</p>
  
  <p><img src="https://i.stack.imgur.com/Vw3Tp.png" alt="error image"></p>