Experience Flutter in the original Android project

1. Manually integrate Flutter into the Android project

1. Flutter support x86_64, armeabi – v7a arm64 – v8a

   android {
     //...
     defaultConfig {
       ndk {
         // Filter forArchitectures supported by Flutter. // Add this if testing using an Android simulator'x86'Platform abiFilters'armeabi-v7a'.'arm64-v8a'.'x86_64'}}}Copy the code

2. Java8 support

   android {
     //...
     compileOptions {
       sourceCompatibility 1.8 targetCompatibility 1.8}}Copy the code

3. Run the command to create a Flutter project, Flutter create -t module –org cn. It200 my_flutter, in the same directory as the existing Android project

4. The configuration Settings. Gradle

   // Include the host app project.
   include ':app'                                    // assumed existing content
   setBinding(new Binding([gradle: this]))                                // new
   evaluate(new File(                                                     // new
     settingsDir.parentFile,                                              // new
     'my_flutter/.android/include_flutter.groovy'                         // new
   ))                                                                     // new
   
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5. Relies on the Flutter module for Android projects

   dependencies {
     implementation project(':flutter')}Copy the code

6. The package related to Flutter can be imported normally in Java code and the project is compiled without exception

2. Start the Flutter page in the Activity

1. Register FlutterActivity into the manifest file

   <activity
     android:name="io.flutter.embedding.android.FlutterActivity"
     android:theme="@style/LaunchTheme"
     android:configChanges="orientation|keyboardHidden|keyboard|screenSize|locale|layoutDirection|fontScale|screenLayout|density|uiMode"
     android:hardwareAccelerated="true"
     android:windowSoftInputMode="adjustResize"
   />
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2. Start the FlutterActivity

   / / open the homepage startActivity (FlutterActivity createDefaultIntent (currentActivity)); StartActivity (flutterActivity.withnewEngine ().initialRoute(flutterActivity.withnewEngine ()."/other")
                   .build(MainActivity.this)
   );
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3. FlutterEngine is introduced to speed up startup

   FlutterEngine FlutterEngine = new FlutterEngine(this); flutterEngine.getDartExecutor().executeDartEntrypoint( DartExecutor.DartEntrypoint.createDefault() ); FlutterEngineCache.getInstance().put("my_engine_id", flutterEngine);
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   / / change the way we start startActivity (FlutterActivity withCachedEngine ("my_engine_id").build(MainActivity.this); ) ;Copy the code

4. Initialize the route when importing FlutterEngine

   Insert the following content: after creating the object flutterEngine flutterEngine. GetNavigationChannel () setInitialRoute ("/other");
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Load the Flutter page in your Activity

1. Layout file adds code

   <FrameLayout
       android:layout_weight="1"
       android:id="@+id/fragment_container"
       android:layout_width="match_parent"
       android:layout_height="match_parent" />
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2. Add code to the Activity

   // Define a tag String to represent the FlutterFragment within this
   // Activity's FragmentManager. This value can be whatever you'd like.
   private static final String TAG_FLUTTER_FRAGMENT = "flutter_fragment";
   
   // Declare a local variable to reference the FlutterFragment so that you
   // can forward calls to it later.
   private FlutterFragment flutterFragment;
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   // Get a reference to the Activity's FragmentManager to add a new // FlutterFragment, or find an existing one. FragmentManager fragmentManager = getSupportFragmentManager(); // Attempt to find an existing FlutterFragment, // in case this is not the first time that onCreate() was run. flutterFragment = (FlutterFragment) fragmentManager .findFragmentByTag(TAG_FLUTTER_FRAGMENT); // Create and attach a FlutterFragment if one does not exist. if (flutterFragment == null) { flutterFragment = FlutterFragment.createDefault(); fragmentManager .beginTransaction() .add( R.id.fragment_container, flutterFragment, TAG_FLUTTER_FRAGMENT ) .commit(); }Copy the code

   @Override
   public void onPostResume() {
       super.onPostResume();
       flutterFragment.onPostResume();
   }
   
   @Override
   protected void onNewIntent(@NonNull Intent intent) {
       super.onNewIntent(intent);
       flutterFragment.onNewIntent(intent);
   }
   
   @Override
   public void onBackPressed() {
       flutterFragment.onBackPressed();
   }
   
   @Override
   public void onRequestPermissionsResult(
           int requestCode,
           @NonNull String[] permissions,
           @NonNull int[] grantResults
   ) {
       flutterFragment.onRequestPermissionsResult(
               requestCode,
               permissions,
               grantResults
       );
   }
   
   @Override
   public void onUserLeaveHint() {
       flutterFragment.onUserLeaveHint();
   }
   
   @Override
   public void onTrimMemory(int level) {
       super.onTrimMemory(level);
       flutterFragment.onTrimMemory(level);
   }
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3. Using FlutterFragment. WithCachedEngine (” my_engine_id “). The build (); accelerating

   if (flutterFragment == null) {
       flutterFragment = FlutterFragment.withCachedEngine("my_engine_id").build();
       fragmentManager
               .beginTransaction()
               .add(
                       R.id.fragment_container,
                       flutterFragment,
                       TAG_FLUTTER_FRAGMENT
               )
               .commit();
   }
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