android - 使用 Material Button 会产生 ClassNotFound 运行时错误

Question

我正在使用 <com.google.android.material.button.MaterialButton 将应用程序中的按钮替换为 Material Buttons |在 XML 文件和 private MaterialButton dateButton;在 Java fragment 文件中。 我研究了代码实验室“MDC-101 Android: Material Components (MDC) Basics (Java)”以了解如何使用 Material Button。在 gradle.build (Module:app) 文件中，我添加了代码实验室中的依赖项。 代码实验室编译并运行良好。我的应用程序编译正常，但在扩展 fragment 布局时出错:

E/AndroidRuntime: FATAL EXCEPTION: main
              Process: nl.kl_solutions.schedulecompareforzermelo, PID: 16708
              android.view.InflateException: Binary XML file line #26: Binary XML file line #26: Error inflating class com.google.android.material.button.MaterialButton
              Caused by: android.view.InflateException: Binary XML file line #26: Error inflating class com.google.android.material.button.MaterialButton
              Caused by: java.lang.ClassNotFoundException: Didn't find class "com.google.android.material.button.MaterialButton" on path: DexPathList[[zip file "/data/app/nl.kl_solutions.schedulecompareforzermelo-o6fuvqQPirym08EhaTRI6Q==/base.apk", zip file "/data/app/nl.kl_solutions.schedulecompareforzermelo-o6fuvqQPirym08EhaTRI6Q==/split_lib_dependencies_apk.apk", zip file "/data/app/nl.kl_solutions.schedulecompareforzermelo-o6fuvqQPirym08EhaTRI6Q==/split_lib_resources_apk.apk", zip file "/data/app/nl.kl_solutions.schedulecompareforzermelo-o6fuvqQPirym08EhaTRI6Q==/split_lib_slice_0_apk.apk", zip file "/data/app/nl.kl_solutions.schedulecompareforzermelo-o6fuvqQPirym08EhaTRI6Q==/split_lib_slice_1_apk.apk", zip file "/data/app/nl.kl_solutions.schedulecompareforzermelo-o6fuvqQPirym08EhaTRI6Q==/split_lib_slice_2_apk.apk", zip file "/data/app/nl.kl_solutions.schedulecompareforzermelo-o6fuvqQPirym08EhaTRI6Q==/split_lib_slice_3_apk.apk", zip file "/data/app/nl.kl_solutions.schedulecompareforzermelo-o6fuvqQPirym08EhaTRI6Q==/split_lib_slice_4_apk.apk", zip file "/data/app/nl.kl_solutions.schedulecompareforzermelo-o6fuvqQPirym08EhaTRI6Q==/split_lib_slice_5_apk.apk", zip file "/data/app/nl.kl_solutions.schedulecompareforzermelo-o6fuvqQPirym08EhaTRI6Q==/split_lib_slice_6_apk.apk", zip file "/data/app/nl.kl_solutions.schedulecompareforzermelo-o6fuvqQPirym08EhaTRI6Q==/split_lib_slice_7_apk.apk", zip file "/data/app/nl.kl_solutions.schedulecompareforzermelo-o6fuvqQPirym08EhaTRI6Q==/split_lib_slice_8_apk.apk", zip file "/data/app/nl.kl_solutions.schedulecompareforzermelo-o6fuvqQPirym08EhaTRI6Q==/split_lib_slice_9_apk.apk"],nativeLibraryDirectories=[/data/app/nl.kl_solutions.schedulecompareforzermelo-o6fuvqQPirym08EhaTRI6Q==/lib/x86_64, /system/lib64]]
                  at dalvik.system.BaseDexClassLoader.findClass(BaseDexClassLoader.java:134)

这是我的布局文件中的一个 fragment :

<LinearLayout
    android:layout_width="match_parent"
    android:layout_height="wrap_content"
    android:orientation="horizontal"
    android:background="@color/primaryLightColor"
    android:paddingLeft="@dimen/rasterleftpadding"
    android:paddingRight="@dimen/rasterrightpadding" >

    <Button
        android:id="@+id/btn_previous"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_weight="1"
        android:layout_gravity="left"
        android:text="prev" />

    <com.google.android.material.button.MaterialButton
        android:id="@+id/btn_week"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_gravity="center"
        android:layout_weight="1"
         />

    <Button
        android:id="@+id/btn_next"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_gravity="right"
        android:layout_weight="1"
        android:text="next" />

</LinearLayout>

这是来自 onCreateView 的 fragment :

@Override
public View onCreateView(LayoutInflater inflater, ViewGroup container,
                         Bundle savedInstanceState) {
    // Inflate the layout for this fragment
    View fragmentLayout = inflater.inflate(R.layout.fragment_week_schedule, container, false);
    //get references to the buttonBar buttons.
    leftButton = fragmentLayout.findViewById(R.id.btn_previous);
    rightButton = fragmentLayout.findViewById(R.id.btn_next);
    dateButton = fragmentLayout.findViewById(R.id.btn_week);

我只将日期按钮更改为 Material 按钮，这给了我错误。当为 dateButton 使用普通 Button 时，该应用程序运行良好。

这是我的 gradle.build 文件:

dependencies {
implementation fileTree(dir: 'libs', include: ['*.jar'])
implementation "com.android.support:appcompat-v7:$rootProject.supportVersion"
implementation "com.android.support:preference-v7:$rootProject.supportVersion"
implementation "com.android.support:recyclerview-v7:$rootProject.supportVersion"
implementation "com.android.support:cardview-v7:$rootProject.supportVersion"
implementation "com.android.support.constraint:constraint-layout:1.1.3"
implementation "com.android.support:design:$rootProject.supportVersion"
implementation "com.android.support:support-v4:$rootProject.supportVersion"
implementation 'com.google.code.gson:gson:2.8.5'
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'

//database components
implementation "android.arch.persistence.room:runtime:$rootProject.roomVersion"
annotationProcessor "android.arch.persistence.room:compiler:$rootProject.roomVersion"

// Lifecycle components
implementation "android.arch.lifecycle:extensions:$rootProject.archLifecycleVersion"
annotationProcessor "android.arch.lifecycle:compiler:$rootProject.archLifecycleVersion"
//QR library
implementation 'me.dm7.barcodescanner:zxing:1.9.8'

其中 $rootProject.supportVersion 是 28.0.0-beta01。我知道某些库的 rc-01 和 rc02 可用，但我使用 beta01 依赖项运行代码实验室，因此决定保留此版本以尽量减少更改。

有人知道导致运行时错误的原因吗？

Answer 1

正如它所暗示的那样HERE你必须在你的 build.gradle 中添加一个依赖:

implementation 'com.google.android.material:material:1.0.0-beta01'

或者，如果您已经在使用谷歌支持设计库，则必须更改您的应用主题以继承 Material Components 主题

<style name="Theme.MyApp" parent="Theme.MaterialComponents.Light">
<!-- ... -->

如果您无法将主题更改为从 Material Components 主题继承，则可以从 Material Components Bridge 主题继承。

<style name="Theme.MyApp" parent="Theme.MaterialComponents.Light.Bridge">
<!-- ... -->

Reyske 是怎么说的:

请注意，它现在已经过测试版了!所以你可以使用实现'com.google.android.material:material:1.0.0'