Android Studio 3.1.3, design view is always empty

Question

I'm new to android development and I have this problem with my Android Studio 3.1.3 demo project or any project that I create.

Even though that I can drag and drop different controls on my design view (ConstraintLayout) but nothing shows on the design view, it shows for a split sec and then it disappears.

I can see all the elements which I drag and drop in activity_main.xml Text tab, Component Tree and even in run mode, but not in design tab, nothing shows in design view and it is always blank not even hello world shows on it.

I tried Invalidate Cache Restart, Restarting my PC, changing Zoom - In and out, Inferring constraints, but no luck. Controls

I can't do much unless I see things in design view.

Empty Design View:

Run mode view

activity_main.xml

<?xml version="1.0" encoding="utf-8"?> <android.support.constraint.ConstraintLayout xmlns:android="http://schemas.android.com/apk/res/android"     xmlns:app="http://schemas.android.com/apk/res-auto"     xmlns:tools="http://schemas.android.com/tools"     android:layout_width="match_parent"     android:layout_height="match_parent"     tools:context=".MainActivity">      <Button         android:id="@+id/button2"         android:layout_width="wrap_content"         android:layout_height="wrap_content"         android:text="Button" />      <Button         android:id="@+id/button4"         android:layout_width="wrap_content"         android:layout_height="0dp"         android:text="Button" />      <android.support.constraint.Guideline         android:id="@+id/guideline"         android:layout_width="wrap_content"         android:layout_height="wrap_content"         android:orientation="vertical"         app:layout_constraintGuide_begin="20dp" />      <CheckBox         android:id="@+id/checkBox"         android:layout_width="wrap_content"         android:layout_height="wrap_content"         android:text="CheckBox"         tools:layout_editor_absoluteX="154dp"         tools:layout_editor_absoluteY="181dp" />  </android.support.constraint.ConstraintLayout> 

AndroidManifest.xml

<?xml version="1.0" encoding="utf-8"?> <manifest xmlns:android="http://schemas.android.com/apk/res/android"     package="com.example.libra.myapplication">      <application         android:allowBackup="true"         android:icon="@mipmap/ic_launcher"         android:label="@string/app_name"         android:roundIcon="@mipmap/ic_launcher_round"         android:supportsRtl="true"         android:theme="@style/AppTheme">         <activity android:name=".MainActivity">             <intent-filter>                 <action android:name="android.intent.action.MAIN" />                  <category android:name="android.intent.category.LAUNCHER" />             </intent-filter>         </activity>     </application>  </manifest> 

build.gradle

apply plugin: 'com.android.application'  android {     compileSdkVersion 28     defaultConfig {         applicationId "com.example.libra.myapplication"         minSdkVersion 15         targetSdkVersion 28         versionCode 1         versionName "1.0"         testInstrumentationRunner "android.support.test.runner.AndroidJUnitRunner"     }     buildTypes {         release {             minifyEnabled false             proguardFiles getDefaultProguardFile('proguard-android.txt'), 'proguard-rules.pro'         }     } }  dependencies {     implementation fileTree(dir: 'libs', include: ['*.jar'])     implementation 'com.android.support:appcompat-v7:28.0.0-alpha3'     implementation 'com.android.support.constraint:constraint-layout:1.1.2'     testImplementation 'junit:junit:4.12'     androidTestImplementation 'com.android.support.test:runner:1.0.2'     androidTestImplementation 'com.android.support.test.espresso:espresso-core:3.0.2' } 

Answer 1

Ok my problem is solved!

The following classes could not be instantiated: - android.support.v7.widget.Toolbar

I changed the res/values/styles.xml file from this:

<style name="AppTheme" parent="Theme.AppCompat.Light.DarkActionBar"> 

to this:

<style name="AppTheme" parent="Base.Theme.AppCompat.Light.DarkActionBar"> 

and that solved the problem