Flutter升级及开发问题汇总

开发集成环境
[✓] Flutter (Channel stable, v1.12.13+hotfix.9, on Mac OS X 10.14.6 18G103, locale zh-Hans-CN)

一、简述Flutter集成到Android原生项目
二、Android原生以AAR形式集成Flutter项目
三、Flutter与原生(Android/IOS)的消息通信
四、Flutter中如何使用原生控件/组件
五、Flutter状态管理Provider与Redux
六、Flutter升级及开发中遇到的问题汇总

此前记录的关于升级到Flutter V1.12与之前版本异同点

  1. 不需要在Application中初始化

    去除FlutterMain.startInitialization(this); 初始化方法。

  2. io.flutter.facade包已移除,flutterView不再建议使用

  3. 原来的FlutterActivity包路径替换

    io.flutter.app.FlutterActivity 替换成 io.flutter.embedding.android.FlutterActivity

  4. 修改启动FlutterActivity方法

    官方启动方式:

    startActivity(
          FlutterActivity
            .withNewEngine()
            .initialRoute("/test")
            .build(currentActivity)
          );
    

    稍微走进FlutterActivity源码你会发现:

      @NonNull
      public static NewEngineIntentBuilder withNewEngine() {
        return new NewEngineIntentBuilder(FlutterActivity.class);
      }
    
      protected NewEngineIntentBuilder(@NonNull Class<? extends FlutterActivity> activityClass) {
          this.activityClass = activityClass;
        }
    
        @NonNull
        public Intent build(@NonNull Context context) {
          return new Intent(context, activityClass)
              .putExtra(EXTRA_INITIAL_ROUTE, initialRoute)
              .putExtra(EXTRA_BACKGROUND_MODE, backgroundMode)
              .putExtra(EXTRA_DESTROY_ENGINE_WITH_ACTIVITY, true);
        }
    

    可以看出这个withNewEngine方法传的一直都是FlutterActivity.class,然后new一个NewEngineIntentBuilder,而NewEngineIntentBuilder的构造函数是protected,不是子类没法直接new。那只好继承NewEngineIntentBuilder这个类,重写它的构造函数。

    改造如下:

    public class MyFlutterActivity extends FlutterActivity {
    
        public static void openFlutter(Activity activity, String routerUrl){
            Intent intent = MyFlutterActivity.withNewEngine()
                    .initialRoute(routerUrl)
                    .build(activity);
            //主要加入这句话实现透明Activity
            //intent.putExtra("background_mode","transparent");
            activity.startActivity(intent);
        }
    
        public static AhsEngineIntentBuilder withNewEngine() {
            return new AhsEngineIntentBuilder(MyFlutterActivity.class);
        }
    
        public static AhsEngineIntentBuilder withNewEngine(Class<? extends FlutterActivity> activityClass) {
            return new AhsEngineIntentBuilder(activityClass);
        }
    
        public static class AhsEngineIntentBuilder extends NewEngineIntentBuilder {
    
            protected AhsEngineIntentBuilder(Class<? extends FlutterActivity> activityClass) {
                super(activityClass);
            }
        }
    }
    
  5. 启动FlutterActivity过渡的图片

    为了启动了FlutteActivity后加载flutter过程中显示的图片,没设置一般是白屏或者黑屏。
    如果你之前设置了android:name="io.flutter.app.android.SplashScreenUntilFirstFrame".需要移除掉.

    添加如下代码:

    <!-- 在所在的activity中加入 -->
    <meta-data
                android:name="io.flutter.embedding.android.SplashScreenDrawable"
                android:resource="@drawable/placehold_background" />
    
  6. flutter出现黑屏无法显示

    需要在flutter的main函数中,runApp前调用如下方法即可:

    void main() {
      WidgetsFlutterBinding.ensureInitialized();
      runApp(MyApp());
    }
    
  7. MethodChannel的应用

    MethodChannel(flutterEngine.dartExecutor.binaryMessenger, CHANNEL).setMethodCallHandler() 
    

    改成:

    MethodChannel(flutterEngine.dartExecutor, CHANNEL).setMethodCallHandler()
    

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