Android Studio 选项卡和 ViewPager 渲染

Question

我一直在开发一个涉及 Fragment 的简单应用程序。我在 XML 文件中使用了 viewpager 和 TabLayout。显示一个错误：渲染问题以及 2 个警告：i) 缺少样式 ii) 无法实例化一个或多个类。在渲染问题中显示以下错误： "Failed to find style 'tabStyle' in current theme".

缺少样式： "Missing styles. Is the correct theme chosen for this layout? Use the Theme combo box above the layout to choose a different layout, or fix the theme style references."

无法实例化一个或多个类： “无法实例化以下类： - android.support.design.widget.TabLayout（打开 Class、显示异常、清除缓存） - android.support.v4.view.ViewPager（打开 Class、显示异常、清除缓存）提示：在您的自定义视图中使用 View.isInEditMode() 以跳过代码或在 IDE 中显示样本数据。如果这是意外错误，您还可以尝试构建项目，然后手动刷新布局。异常详情 java.lang.ClassNotFoundException: android.view.View$OnUnhandledKeyEventListener " enter image description here

Manifest.xml:

<?xml version="1.0" encoding="utf-8"?>
<manifest xmlns:android="http://schemas.android.com/apk/res/android"
package="com.example.utkarsh.kannadaseekhae">

<application
    android:allowBackup="true"
    android:icon="@mipmap/ic_launcher"
    android:label="@string/app_name"
    android:roundIcon="@mipmap/ic_launcher_round"
    android:supportsRtl="true"
    android:theme="@style/AppTheme">
    <activity android:name=".MainActivity">
        <intent-filter>
            <action android:name="android.intent.action.MAIN" />

            <category android:name="android.intent.category.LAUNCHER" 
 />
        </intent-filter>
    </activity>

</application>

activity_main.xml:

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout 
xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:app="http://schemas.android.com/apk/res-auto"
xmlns:tools="http://schemas.android.com/tools"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:background="@color/primary_color"
android:orientation="vertical"
tools:context=".MainActivity">


<android.support.design.widget.TabLayout
    android:id="@+id/tabs"
    style="@style/CategoryTab"
    android:layout_width="match_parent"
    android:layout_height="wrap_content"
    app:tabIndicatorHeight="48dp" />

<android.support.v4.view.ViewPager
    android:id="@+id/viewpager"
    android:layout_width="match_parent"
    android:layout_height="match_parent" />

</LinearLayout>

Styles.xml:

<resources>

<!-- Base application theme. -->
<style name="AppTheme" 
parent="Base.Theme.AppCompat.Light.DarkActionBar">
    <item name="colorPrimary">@color/primary_color</item>
    <item name="colorPrimaryDark">@color/primary_dark_color</item>
    <item name="actionBarStyle">@style/KannadaAppBarStyle</item>
    <item name="android:windowContentOverlay">@null</item>
</style>

<!-- App bar style -->
<style name="KannadaAppBarStyle" parent="@android:style/Widget.DeviceDefault.Light.ActionBar.Solid.Inverse">
    <!-- Remove the shadow below the app bar -->
    <item name="elevation">0dp</item>
</style>

<!-- Style for a tab that displays a category name -->
<style name="CategoryTab" parent="Widget.Design.TabLayout">
    <item name="tabIndicatorColor">@android:color/white</item>
    <item name="tabSelectedTextColor">@android:color/white</item>
    <item 
 name="tabTextAppearance">@style/CategoryTabTextAppearance</item>
</style>

<!-- Text appearance style for a category tab -->
<style name="CategoryTabTextAppearance" 
parent="TextAppearance.Design.Tab">
    <item name="android:textColor">#A8A19E</item>
</style>
</resources>

Gradle 建造：

apply plugin: 'com.android.application'

android { compileSdk版本28 默认配置{ 应用程序 ID "com.example.utkarsh.kannadaseekhae" minSdkVersion 15 targetSdk版本 28 版本代码 1 版本名称“1.0” 测试仪器运行器 "android.support.test.runner.AndroidJUnitRunner" } buildTypes { 发布 { minifyEnabled 假 proguardFiles getDefaultProguardFile('proguard-android.txt'), 'proguard-rules.pro' } } }

dependencies {
    implementation fileTree(dir: 'libs', include: ['*.jar'])
    implementation 'com.android.support:appcompat-v7:28.0.0-rc01'
    implementation 'com.android.support.constraint:constraint- 
layout:1.1.2'
implementation 'com.android.support:support-v4:28.0.0-rc01'
implementation 'com.android.support:design:28.0.+'
testImplementation 'junit:junit:4.12'
androidTestImplementation 'com.android.support.test:runner:1.0.2'
androidTestImplementation 'com.android.support.test.espresso:espresso- 
core:3.0.2'
}

MainActivity.java:

public class MainActivity extends AppCompatActivity {

@Override
protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);

    // Set the content of the activity to use the activity_main.xml 
 layout file
    setContentView(R.layout.activity_main);

    // Find the view pager that will allow the user to swipe between 
fragments
    ViewPager viewPager = findViewById(R.id.viewpager);

    // Create an adapter that knows which fragment should be shown on 
each page
    CategoryAdapter adapter = new CategoryAdapter(this, 
getSupportFragmentManager());

    // Set the adapter onto the view pager
    viewPager.setAdapter(adapter);

    // Find the tab layout that shows the tabs
    TabLayout tabLayout = findViewById(R.id.tabs);

    // Connect the tab layout with the view pager. This will
    //   1. Update the tab layout when the view pager is swiped
    //   2. Update the view pager when a tab is selected
    //   3. Set the tab layout's tab names with the view pager's 
adapter's titles
    //      by calling onPageTitle()
    tabLayout.setupWithViewPager(viewPager);
    }
}

Answer 1

只需将支持库版本更改为 alpha1

它应该看起来像

implementation 'com.android.support:appcompat-v7:28.0.0-alpha1'
implementation 'com.android.support:design:28.0.0-alpha1'

Android Studio 选项卡和 ViewPager 渲染

Android Studio Tabs and ViewPager Rendering

xml

android

android-layout

android-support-library

android-studio