Flutter&Android 启动页（闪屏页）的加载流程和优化方案

flutterView = new FlutterView(host.getActivity(), flutterSurfaceView);

} else {

FlutterTextureView flutterTextureView = new FlutterTextureView(host.getActivity());

// Allow our host to customize FlutterSurfaceView, if desired.

host.onFlutterTextureViewCreated(flutterTextureView);

// Create the FlutterView that owns the FlutterTextureView.

flutterView = new FlutterView(host.getActivity(), flutterTextureView);

}

// Add listener to be notified when Flutter renders its first frame.

flutterView.addOnFirstFrameRenderedListener(flutterUiDisplayListener);

/// 创建一个闪屏 view – FlutterSplashView

flutterSplashView = new FlutterSplashView(host.getContext());

if (Build.VERSION.SDK_INT>= Build.VERSION_CODES.JELLY_BEAN_MR1) {

flutterSplashView.setId(View.generateViewId());

} else {

// TODO(mattcarroll): Find a better solution to this ID. This is a random, static ID.

// It might conflict with other Views, and it means that only a single FlutterSplashView

// can exist in a View hierarchy at one time.

flutterSplashView.setId(486947586);

}

/// 显示闪屏页

flutterSplashView.displayFlutterViewWithSplash(flutterView, host.provideSplashScreen());

Log.v(TAG,“Attaching FlutterEngine to FlutterView.”);

/// 所创建 surface 绑定到 engine 上

flutterView.attachToFlutterEngine(flutterEngine);

return flutterSplashView;

}

这里我们可以大致了解到，创建了一个 FlutterSurfaceView 它继承自 surfaceView(我们的 flutter 页面也是渲染在这个 surface 上的)。之后我们用它初始化一个 FlutterView，

FlutterView 继承自 FrameLayout

随后我们再创建一个 FlutterSplashView（继承 FrameLayout）并调用 displayFlutterViewWithSplash（）方法。

public void displayFlutterViewWithSplash(

@NonNull FlutterView flutterView, @Nullable SplashScreen splashScreen) {

// If we were displaying a previous FlutterView, remove it.

if (this.flutterView != null) {

this.flutterView.removeOnFirstFrameRenderedListener(flutterUiDisplayListener);

removeView(this.flutterView);

}

// If we were displaying a previous splash screen View, remove it.

if (splashScreenView != null) {

removeView(splashScreenView);

}

// Display the new FlutterView.

this.flutterView = flutterView;

/// 添加 flutterView

addView(flutterView);