【移動應(yīng)用開發(fā)技術(shù)】如何實現(xiàn)Flutter啟動頁

【移動應(yīng)用開發(fā)技術(shù)】如何實現(xiàn)Flutter啟動頁

為什么要有啟動頁？Android啟動流程/upload/information/20200623/125/118885.jpgFlutter啟動頁具體實現(xiàn)和原理public

class

SplashActivity

extends

FlutterActivity

{

@Override

protected

void

onCreate(Bundle

savedInstanceState)

{

super.onCreate(savedInstanceState);

GeneratedPluginRegistrant.registerWith(this);

}

}

<activity

android:name=".SplashActivity"

android:configChanges="orientation|keyboardHidden|keyboard|screenSize|locale|layoutDirection|fontScale|screenLayout|density|uiMode"

android:hardwareAccelerated="true"

android:launchMode="singleTop"

android:theme="@style/LaunchTheme"

android:windowSoftInputMode="adjustResize">

<meta-data

android:name="io.flutter.app.android.SplashScreenUntilFirstFrame"

android:value="true"

/>

<intent-filter>

<action

android:name="ent.action.MAIN"

/>

<category

android:name="ent.category.LAUNCHER"

/>

</intent-filter>

</activity>/upload/information/20200623/125/118886.gifpublic

final

class

FlutterActivityDelegate

implements

FlutterActivityEvents,

FlutterView.Provider,

PluginRegistry

{

private

static

final

String

SPLASH_SCREEN_META_DATA_KEY

=

"io.flutter.app.android.SplashScreenUntilFirstFrame";

private

View

launchView;

@Override

public

void

onCreate(Bundle

savedInstanceState)

{

String[]

args

=

getArgsFromIntent(activity.getIntent());

FlutterMain.ensureInitializationComplete(activity.getApplicationContext(),

args);

flutterView

=

viewFactory.createFlutterView(activity);

if

(flutterView

==

null)

{

FlutterNativeView

nativeView

=

viewFactory.createFlutterNativeView();

flutterView

=

new

FlutterView(activity,

null,

nativeView);

flutterView.setLayoutParams(matchParent);

activity.setContentView(flutterView);

launchView

=

createLaunchView();//1

if

(launchView

!=

null)

{

addLaunchView();//2

}

}

}

private

View

createLaunchView()

{

if

(!showSplashScreenUntilFirstFrame())

{//3

return

null;

}

final

Drawable

launchScreenDrawable

=

getLaunchScreenDrawableFromActivityTheme();

final

View

view

=

new

View(activity);

view.setBackground(launchScreenDrawable);

return

view;

}

private

Drawable

getLaunchScreenDrawableFromActivityTheme()

{

//省略了部分代碼

try

{

return

activity.getResources().getDrawable(typedValue.resourceId);

}

catch

(NotFoundException

e)

{

return

null;

}

}

private

Boolean

showSplashScreenUntilFirstFrame()

{

try

{

ActivityInfo

activityInfo

=

activity.getPackageManager().getActivityInfo(

activity.getComponentName(),

PackageManager.GET_META_DATA|PackageManager.GET_ACTIVITIES);

Bundle

metadata

=

activityInfo.metaData;

return

metadata

!=

null

&&

metadata.getBoolean(SPLASH_SCREEN_META_DATA_KEY);

}

catch

(NameNotFoundException

e)

{

return

false;

}

}

private

void

addLaunchView()

{

activity.addContentView(launchView,

matchParent);//4

flutterView.addFirstFrameListener(new

FlutterView.FirstFrameListener()

{//5

@Override

public

void

onFirstFrame()

{

FlutterActivityDelegate.this.launchView.animate()

.alpha(0f)

.setListener(new

AnimatorListenerAdapter()

{

@Override

public

void

onAnimationEnd(Animator

animation)

{

((ViewGroup)

FlutterActivityDelegate.this.launchView.getParent())

.removeView(FlutterActivityDelegate.this.launchView);//5

}

});

}

});

activity.setTheme(android.R.style.Theme_Black_NoTitleBar);

}

}注釋1注釋3注釋2<resources>

<style

name="LaunchTheme"

parent="@android:style/Theme.Black.NoTitleBar">

<!--

Show

a

splash

screen

on

the

activity.

Automatically

removed

when

Flutter

draws

its

first

frame

-->

<item

name="android:windowBackground">@drawable/launch_background</item>

</style>

</resources><?xml

version="1.0"

encoding="utf-8"?>

<layer-list

xmlns:android="/apk/res/android"

android:opacity="opaque">

<item>

<bitmap

android:src="@mipmap/ic_launch_bg"

/>

</ite