小编Moh*_*oel的帖子

我希望实现如图所示的这样的东西

我尝试过这段代码,但无法在顶部图片或工具栏下方固定按钮

在这个我试图有工具栏和下面我有嵌套scrollview和内部滚动视图我有一个滚动视图(scrollview2).

我想将一个按钮固定或锚定到scrollview2,当我向上滚动此scrollview2时,我想要按钮固定到工具栏

 <?xml version="1.0" encoding="utf-8"?>
<android.support.design.widget.CoordinatorLayout xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:app="http://schemas.android.com/apk/res-auto"
android:layout_width="match_parent"
android:layout_height="match_parent">

<android.support.design.widget.AppBarLayout
    android:id="@+id/app_bar_layout"
    android:layout_width="match_parent"
    android:layout_height="350dp"
    android:fitsSystemWindows="true"
    android:theme="@style/ThemeOverlay.AppCompat.Dark.ActionBar">



    <android.support.v7.widget.Toolbar
        android:id="@+id/toolbar"
        android:layout_width="match_parent"
        android:layout_height="350dp"
        app:layout_collapseMode="pin"
        app:popupTheme="@style/ThemeOverlay.AppCompat.Light">

        <ImageView
            android:id="@+id/homescrn_logo"
            android:layout_width="match_parent"
            android:layout_height="350dp"
            android:scaleType="fitXY"
            android:src="@drawable/restaurant"
            app:layout_collapseMode="parallax" />

    </android.support.v7.widget.Toolbar>


</android.support.design.widget.AppBarLayout>


<android.support.v4.widget.NestedScrollView
    android:layout_width="match_parent"
    android:layout_height="wrap_content"
    app:layout_behavior="@string/appbar_scrolling_view_behavior">

    <LinearLayout
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:orientation="vertical">

        <android.support.v4.widget.NestedScrollView
            android:id="@+id/scrlview"
            android:layout_width="match_parent"
            android:layout_height="wrap_content">

            <LinearLayout
                android:layout_width="match_parent"
                android:layout_height="match_parent"
                android:orientation="vertical">

                <ImageView
                    android:layout_width="200dp"
                    android:layout_height="200dp"
                    android:layout_alignParentRight="true"
                    android:src="@drawable/restaurant" />

                <ImageView
                    android:layout_width="200dp"
                    android:layout_height="200dp"
                    android:layout_alignParentRight="true"
                    android:src="@drawable/restaurant" />

                <ImageView
                    android:layout_width="200dp"
                    android:layout_height="200dp"
                    android:layout_alignParentRight="true"
                    android:src="@drawable/restaurant" />

                <ImageView
                    android:layout_width="200dp"
                    android:layout_height="200dp"
                    android:layout_alignParentRight="true"
                    android:src="@drawable/restaurant" />

                <LinearLayout
                    android:layout_width="match_parent"
                    android:layout_height="200dp"
                    android:background="@color/colorAccent"></LinearLayout>

                <ImageView
                    android:layout_width="200dp" …

我正在使用dagger2库.每当我试图运行我的项目时,都表示无法创建视图模型类的实例.

我正在尝试创建实例的主要活动

   ((MovieApplication) getApplication()).getAppComponent().inject(this);
    mViewModel = ViewModelProviders.of(this).get(MoviesDataViewModel.class);

我的工厂班

public class ViewModelFactory implements ViewModelProvider.Factory {
private MoviesDataViewModel mViewModel;

@Inject
public ViewModelFactory(MoviesDataViewModel viewModel) {
    this.mViewModel = viewModel;
}

@Override
public <T extends ViewModel> T create(Class<T> modelClass) {
    if (modelClass.isAssignableFrom(MoviesDataViewModel.class)) {
        return (T) mViewModel;
    }
    throw new IllegalArgumentException("Unknown class name");
}

我的日志

  Caused by: java.lang.RuntimeException: Cannot create an instance of class com.moviedata.viewmodel.MoviesDataViewModel
                                                               at android.arch.lifecycle.ViewModelProvider$NewInstanceFactory.create(ViewModelProvider.java:145)
                                                               at android.arch.lifecycle.ViewModelProviders$DefaultFactory.create(ViewModelProviders.java:143)
                                                               at android.arch.lifecycle.ViewModelProvider.get(ViewModelProvider.java:128)
                                                               at android.arch.lifecycle.ViewModelProvider.get(ViewModelProvider.java:96)
                                                               at com.moviedata.ui.MainActivity.onCreate(MainActivity.java:28)
                                                               at android.app.Activity.performCreate(Activity.java:6321)
                                                               at android.app.Instrumentation.callActivityOnCreate(Instrumentation.java:1108)
                                                               at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2426)
                                                               at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:2535) 
                                                               at android.app.ActivityThread.access$1100(ActivityThread.java:154) 
                                                               at …

在 podfile 中启用 Hermes 引擎后，在构建应用程序时会抛出错误

"Undefined symbols for architecture x86_64: "vtable for facebook::react::HermesExecutorFactory"

爱马仕版本：0.9.0

RN：0.66.1

pod 文件

 platform :ios, '11.0'
 target 'OneSignalNotificationServiceExtension' do
 pod 'react-native-onesignal', :path => '../node_modules/react-native-onesignal'
end

target '****' do
# Pods for ****
config = use_native_modules!
use_react_native!(path: config['reactNativePath'])

use_react_native!(
:path => config[:reactNativePath],
# to enable hermes on iOS, change `false` to `true` and then install pods
:hermes_enabled => true

）

错误