我正在开发android应用程序，我已经使用了MaterialCardView，但我得到了以下异常
the following classes could not be instantiated:
- com.google.android.material.card.MaterialCardView (Open Class, Show Exception, Clear Cache)
Tip: Use View.isInEditMode() in your custom views to skip code or show sample data when shown in the IDE. If this is an unexpected error you can also try to build the project, then manually refresh the layout. Exception Details java.lang.ClassNotFoundException: com.google.android.material.R$attr at java.lang.ClassLoader.loadClass(ClassLoader.java:419) at java.lang.ClassLoader.loadClass(ClassLoader.java:352) at com.google.android.material.card.MaterialCardView.<clinit> ... (MaterialCardView.java:90) at java.lang.reflect.Constructor.newInstance(Constructor.java:423) at android.view.LayoutInflater.createViewFromTag(LayoutInflater.java:961) at android.view.LayoutInflater.inflate(LayoutInflater.java:659) at android.view.LayoutInflater.inflate(LayoutInflater.java:501) Copy stack to clipboard
在我使用MaterialCardView 的xml文件下面
<?xml version="1.0" encoding="utf-8"?>
<com.google.android.material.card.MaterialCardView 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="wrap_content"
android:layout_height="wrap_content">
<androidx.constraintlayout.widget.ConstraintLayout
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:padding="10dp">
<androidx.appcompat.widget.AppCompatImageView
android:id="@+id/ivUser"
android:layout_width="100dp"
android:layout_height="100dp"
app:layout_constraintBottom_toBottomOf="parent"
app:layout_constraintLeft_toLeftOf="parent"
app:layout_constraintTop_toTopOf="parent"
tools:srcCompat="@tools:sample/avatars" />
<androidx.appcompat.widget.AppCompatTextView
android:id="@+id/tvName"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_marginStart="10dp"
android:textColor="@color/black"
android:textSize="20sp"
app:layout_constraintStart_toEndOf="@+id/ivUser"
app:layout_constraintTop_toTopOf="parent"
tools:text="TextView"
android:layout_marginLeft="10dp" />
<androidx.appcompat.widget.AppCompatTextView
android:id="@+id/tvAddress"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_marginTop="5dp"
android:textColor="@color/black"
android:textSize="15sp"
app:layout_constraintStart_toStartOf="@+id/tvName"
app:layout_constraintTop_toBottomOf="@+id/tvName"
tools:text="TextView" />
</androidx.constraintlayout.widget.ConstraintLayout>
</com.google.android.material.card.MaterialCardView>
在我的app.gradle 下方
apply plugin: 'com.android.application'
apply plugin: 'kotlin-android'
apply plugin: 'kotlin-android-extensions'
apply plugin: 'kotlin-kapt'
apply plugin: 'dagger.hilt.android.plugin'
android {
compileSdkVersion 30
buildToolsVersion "30.0.2"
defaultConfig {
applicationId "yodgorbekkomilov.edgar.printfultask"
minSdkVersion 15
targetSdkVersion 30
versionCode 1
versionName "1.0"
testInstrumentationRunner "androidx.test.runner.AndroidJUnitRunner"
}
buildTypes {
release {
minifyEnabled false
proguardFiles getDefaultProguardFile('proguard-android-optimize.txt'), 'proguard-rules.pro'
}
}
compileOptions {
sourceCompatibility JavaVersion.VERSION_1_8
targetCompatibility JavaVersion.VERSION_1_8
}
}
dependencies {
implementation fileTree(dir: "libs", include: ["*.jar"])
implementation "org.jetbrains.kotlin:kotlin-stdlib:$kotlin_version"
implementation 'androidx.core:core-ktx:1.3.2'
implementation 'androidx.appcompat:appcompat:1.2.0'
implementation 'androidx.constraintlayout:constraintlayout:2.0.3'
implementation "io.ktor:ktor-client-android:1.4.0"
implementation "io.ktor:ktor-network:1.4.0"
implementation 'com.google.android.gms:play-services-maps:17.0.0'
implementation "com.google.dagger:hilt-android:2.28-alpha"
implementation "androidx.hilt:hilt-lifecycle-viewmodel:1.0.0-alpha02"
kapt "com.google.dagger:hilt-android-compiler:2.28-alpha"
implementation 'com.google.android.material:material:1.2.1'
implementation 'com.github.bumptech.glide:glide:4.11.0'
annotationProcessor 'com.github.bumptech.glide:compiler:4.11.0'
def lifecycle_version = "2.2.0"
def arch_version = "2.1.0"
// ViewModel
implementation "androidx.lifecycle:lifecycle-viewmodel-ktx:$lifecycle_version"
// LiveData
implementation "androidx.lifecycle:lifecycle-livedata-ktx:$lifecycle_version"
// Lifecycles only (without ViewModel or LiveData)
implementation "androidx.lifecycle:lifecycle-runtime-ktx:$lifecycle_version"
implementation 'androidx.fragment:fragment-ktx:1.1.0'
// Saved state module for ViewModel
implementation "androidx.lifecycle:lifecycle-viewmodel-savedstate:$lifecycle_version"
// Annotation processor
kapt "androidx.lifecycle:lifecycle-compiler:$lifecycle_version"
// alternately - if using Java8, use the following instead of lifecycle-compiler
implementation "androidx.lifecycle:lifecycle-common-java8:$lifecycle_version"
// optional - helpers for implementing LifecycleOwner in a Service
implementation "androidx.lifecycle:lifecycle-service:$lifecycle_version"
// optional - ProcessLifecycleOwner provides a lifecycle for the whole application process
implementation "androidx.lifecycle:lifecycle-process:$lifecycle_version"
testImplementation 'junit:junit:4.12'
androidTestImplementation 'androidx.test.ext:junit:1.1.2'
androidTestImplementation 'androidx.test.espresso:espresso-core:3.3.0'
}
在我的夜晚/themes.xml下方
<resources xmlns:tools="http://schemas.android.com/tools">
<!-- Base application theme. -->
<style name="Theme.PrintfulApp" parent="Theme.MaterialComponents.DayNight.NoActionBar">
<!-- Primary brand color. -->
<item name="colorPrimary">@color/purple_200</item>
<item name="colorPrimaryVariant">@color/purple_700</item>
<item name="colorOnPrimary">@color/black</item>
<!-- Secondary brand color. -->
<item name="colorSecondary">@color/teal_200</item>
<item name="colorSecondaryVariant">@color/teal_200</item>
<item name="colorOnSecondary">@color/black</item>
<!-- Status bar color. -->
<item name="android:statusBarColor" tools:targetApi="l">?attr/colorPrimaryVariant</item>
<!-- Customize your theme here. -->
</style>
</resources>
低于值/themes.xml
<resources xmlns:tools="http://schemas.android.com/tools">
<!-- Base application theme. -->
<style name="Theme.PrintfulApp" parent="Theme.MaterialComponents.DayNight.NoActionBar">
<!-- Primary brand color. -->
<item name="colorPrimary">@color/purple_500</item>
<item name="colorPrimaryVariant">@color/purple_700</item>
<item name="colorOnPrimary">@color/white</item>
<!-- Secondary brand color. -->
<item name="colorSecondary">@color/teal_200</item>
<item name="colorSecondaryVariant">@color/teal_700</item>
<item name="colorOnSecondary">@color/black</item>
<!-- Status bar color. -->
<item name="android:statusBarColor" tools:targetApi="l">?attr/colorPrimaryVariant</item>
<!-- Customize your theme here. -->
</style>
</resources>
我想知道我到底在哪里犯了错误，我也尝试过为另一个主题更改，我尝试过使缓存重新启动重建和构建项目无效，并遵循了所有stackoverflow的建议，它没有解决我的问题，任何提示都非常感谢
我试图更新依赖项并使缓存无效，但无济于事。
然后我将Android Studio从Dolphin降级为Chipmunk。您也可以升级它，或者从Beta或Canary版本中选择另一个。