为什么在 android studio 中添加按钮时出现 class 转换异常？
Why am i getting a class cast exception when adding a button in android studio?
我正在使用 Android Studio 3.4，并使用 Material Design。
当我向布局添加一个按钮时，我得到一个 java.lang.ClassCastException@11378fc8，在我删除按钮之前我不能再使用布局编辑器。
我已经尝试过 "invalidate/restart"、重建、清理和构建。
这是我的树结构：
Tree structure
Build.Gradle :
apply plugin: 'com.android.application'
android {
compileSdkVersion 28
defaultConfig {
applicationId "fr.aurelien.test_dessin_android"
minSdkVersion 24
targetSdkVersion 28
versionCode 1
versionName "1.0"
testInstrumentationRunner "androidx.test.runner.AndroidJUnitRunner"
}
buildTypes {
release {
minifyEnabled false
proguardFiles getDefaultProguardFile('proguard-android-optimize.txt'), 'proguard-rules.pro'
}
}
}
dependencies {
implementation fileTree(dir: 'libs', include: ['*.jar'])
implementation 'androidx.appcompat:appcompat:1.0.0-beta01'
implementation 'androidx.constraintlayout:constraintlayout:1.1.3'
implementation 'androidx.legacy:legacy-support-v4:1.0.0-beta01'
implementation 'com.google.android.material:material:1.1.0-alpha06'
implementation 'com.google.code.gson:gson:2.8.5'
testImplementation 'junit:junit:4.12'
androidTestImplementation 'androidx.test:runner:1.1.0-alpha4'
androidTestImplementation 'androidx.test.espresso:espresso-core:3.1.0-alpha4'
}
Class 转换异常：
java.lang.IllegalArgumentException: java.lang.ClassCastException@126d0c4
at sun.reflect.GeneratedMethodAccessor1380.invoke(Unknown Source)
at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
at java.lang.reflect.Method.invoke(Method.java:498)
at android.animation.PropertyValuesHolder_Delegate.callMethod(PropertyValuesHolder_Delegate.java:108)
at android.animation.PropertyValuesHolder_Delegate.nCallFloatMethod(PropertyValuesHolder_Delegate.java:143)
at android.animation.PropertyValuesHolder.nCallFloatMethod(PropertyValuesHolder.java)
at android.animation.PropertyValuesHolder.access0(PropertyValuesHolder.java:38)
at android.animation.PropertyValuesHolder$FloatPropertyValuesHolder.setAnimatedValue(PropertyValuesHolder.java:1387)
at android.animation.ObjectAnimator.animateValue(ObjectAnimator.java:990)
at android.animation.ValueAnimator.setCurrentFraction(ValueAnimator.java:674)
at android.animation.ValueAnimator.start(ValueAnimator.java:1071)
at android.animation.ValueAnimator.start(ValueAnimator.java:1088)
at android.animation.ObjectAnimator.start(ObjectAnimator.java:852)
at android.animation.ValueAnimator.startWithoutPulsing(ValueAnimator.java:1081)
at android.animation.AnimatorSet.handleAnimationEvents(AnimatorSet.java:1142)
at android.animation.AnimatorSet.doAnimationFrame(AnimatorSet.java:1046)
at android.animation.AnimationHandler.doAnimationFrame(AnimationHandler.java:146)
at android.animation.AnimationHandler.access0(AnimationHandler.java:37)
at android.animation.AnimationHandler.doFrame(AnimationHandler.java:54)
at android.view.Choreographer$CallbackRecord.run(Choreographer.java:947)
at android.view.Choreographer.doCallbacks(Choreographer.java:761)
at android.view.Choreographer_Delegate.doFrame(Choreographer_Delegate.java:66)
at com.android.layoutlib.bridge.impl.RenderSessionImpl.renderAndBuildResult(RenderSessionImpl.java:563)
at com.android.layoutlib.bridge.impl.RenderSessionImpl.render(RenderSessionImpl.java:425)
at com.android.layoutlib.bridge.BridgeRenderSession.render(BridgeRenderSession.java:120)
at com.android.ide.common.rendering.api.RenderSession.render(RenderSession.java:151)
at com.android.ide.common.rendering.api.RenderSession.render(RenderSession.java:133)
at com.android.tools.idea.rendering.RenderTask.lambda$null(RenderTask.java:755)
at java.util.concurrent.CompletableFuture$AsyncSupply.run(CompletableFuture.java:1590)
at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1142)
at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:617)
at java.lang.Thread.run(Thread.java:745)
主要活动：
package fr.aurelien.test_dessin_android;
import androidx.fragment.app.FragmentManager;
import androidx.fragment.app.FragmentTransaction;
import androidx.appcompat.app.AppCompatActivity;
import android.os.Bundle;
public class MainActivity extends AppCompatActivity {
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
FragmentManager fragmentManager = getSupportFragmentManager();
FragmentTransaction fragmentTransaction = fragmentManager.beginTransaction();
fragmentTransaction.add(R.id.frameLayout, new SimpleFragment());
fragmentTransaction.commit();
}
}
片段class：
package fr.aurelien.test_dessin_android;
import android.os.Bundle;
import androidx.annotation.NonNull;
import androidx.annotation.Nullable;
import androidx.fragment.app.Fragment;
import android.view.LayoutInflater;
import android.view.View;
import android.view.ViewGroup;
public class SimpleFragment extends Fragment {
@Nullable
@Override
public View onCreateView(@NonNull LayoutInflater inflater, @Nullable ViewGroup container, @Nullable Bundle savedInstanceState) {
View retView = inflater.inflate(R.layout.fragment_layout, container, false);
return retView;
}
}
Manifest.xml :
<?xml version="1.0" encoding="utf-8"?>
<manifest xmlns:android="http://schemas.android.com/apk/res/android"
package="fr.aurelien.test_dessin_android">
<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.default">
<activity android:name=".MainActivity">
<intent-filter>
<action android:name="android.intent.action.MAIN" />
<category android:name="android.intent.category.LAUNCHER" />
</intent-filter>
</activity>
</application>
</manifest>
XML 代码：
<?xml version="1.0" encoding="utf-8"?>
<androidx.constraintlayout.widget.ConstraintLayout 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">
<TextView
android:id="@+id/textView"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_marginStart="70dp"
android:layout_marginTop="16dp"
android:text="TextView"
app:layout_constraintStart_toStartOf="parent"
app:layout_constraintTop_toTopOf="parent" />
<ImageView
android:id="@+id/imageView"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_marginStart="55dp"
android:layout_marginTop="31dp"
app:layout_constraintStart_toStartOf="parent"
app:layout_constraintTop_toBottomOf="@+id/textView"
app:srcCompat="@mipmap/ic_launcher" />
<Button
android:id="@+id/button5"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_marginTop="16dp"
android:text="Button"
app:layout_constraintTop_toTopOf="parent"
tools:layout_editor_absoluteX="189dp" />
</androidx.constraintlayout.widget.ConstraintLayout>
您是否尝试过使用 androidx.appcompat.widget.AppCompatButton 而不是 Button？
这是 Android Studio 中的错误。您可以在此处跟踪它，它显然已针对 3.5.2 https://issuetracker.google.com/issues/132316448
修复
如果您想使用 material 组件，您需要将 styles.xml 中的默认主题从 Theme.AppCompat 更改为 Theme.MaterialComponents.
不要忘记添加这个
implementation 'com.google.android.material:material:1.1.0' 在您的应用级别 build.gradle
我正在使用 Android Studio 3.4，并使用 Material Design。 当我向布局添加一个按钮时，我得到一个 java.lang.ClassCastException@11378fc8，在我删除按钮之前我不能再使用布局编辑器。
我已经尝试过 "invalidate/restart"、重建、清理和构建。
这是我的树结构： Tree structure
Build.Gradle :
apply plugin: 'com.android.application'
android {
compileSdkVersion 28
defaultConfig {
applicationId "fr.aurelien.test_dessin_android"
minSdkVersion 24
targetSdkVersion 28
versionCode 1
versionName "1.0"
testInstrumentationRunner "androidx.test.runner.AndroidJUnitRunner"
}
buildTypes {
release {
minifyEnabled false
proguardFiles getDefaultProguardFile('proguard-android-optimize.txt'), 'proguard-rules.pro'
}
}
}
dependencies {
implementation fileTree(dir: 'libs', include: ['*.jar'])
implementation 'androidx.appcompat:appcompat:1.0.0-beta01'
implementation 'androidx.constraintlayout:constraintlayout:1.1.3'
implementation 'androidx.legacy:legacy-support-v4:1.0.0-beta01'
implementation 'com.google.android.material:material:1.1.0-alpha06'
implementation 'com.google.code.gson:gson:2.8.5'
testImplementation 'junit:junit:4.12'
androidTestImplementation 'androidx.test:runner:1.1.0-alpha4'
androidTestImplementation 'androidx.test.espresso:espresso-core:3.1.0-alpha4'
}
Class 转换异常：
java.lang.IllegalArgumentException: java.lang.ClassCastException@126d0c4
at sun.reflect.GeneratedMethodAccessor1380.invoke(Unknown Source)
at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
at java.lang.reflect.Method.invoke(Method.java:498)
at android.animation.PropertyValuesHolder_Delegate.callMethod(PropertyValuesHolder_Delegate.java:108)
at android.animation.PropertyValuesHolder_Delegate.nCallFloatMethod(PropertyValuesHolder_Delegate.java:143)
at android.animation.PropertyValuesHolder.nCallFloatMethod(PropertyValuesHolder.java)
at android.animation.PropertyValuesHolder.access0(PropertyValuesHolder.java:38)
at android.animation.PropertyValuesHolder$FloatPropertyValuesHolder.setAnimatedValue(PropertyValuesHolder.java:1387)
at android.animation.ObjectAnimator.animateValue(ObjectAnimator.java:990)
at android.animation.ValueAnimator.setCurrentFraction(ValueAnimator.java:674)
at android.animation.ValueAnimator.start(ValueAnimator.java:1071)
at android.animation.ValueAnimator.start(ValueAnimator.java:1088)
at android.animation.ObjectAnimator.start(ObjectAnimator.java:852)
at android.animation.ValueAnimator.startWithoutPulsing(ValueAnimator.java:1081)
at android.animation.AnimatorSet.handleAnimationEvents(AnimatorSet.java:1142)
at android.animation.AnimatorSet.doAnimationFrame(AnimatorSet.java:1046)
at android.animation.AnimationHandler.doAnimationFrame(AnimationHandler.java:146)
at android.animation.AnimationHandler.access0(AnimationHandler.java:37)
at android.animation.AnimationHandler.doFrame(AnimationHandler.java:54)
at android.view.Choreographer$CallbackRecord.run(Choreographer.java:947)
at android.view.Choreographer.doCallbacks(Choreographer.java:761)
at android.view.Choreographer_Delegate.doFrame(Choreographer_Delegate.java:66)
at com.android.layoutlib.bridge.impl.RenderSessionImpl.renderAndBuildResult(RenderSessionImpl.java:563)
at com.android.layoutlib.bridge.impl.RenderSessionImpl.render(RenderSessionImpl.java:425)
at com.android.layoutlib.bridge.BridgeRenderSession.render(BridgeRenderSession.java:120)
at com.android.ide.common.rendering.api.RenderSession.render(RenderSession.java:151)
at com.android.ide.common.rendering.api.RenderSession.render(RenderSession.java:133)
at com.android.tools.idea.rendering.RenderTask.lambda$null(RenderTask.java:755)
at java.util.concurrent.CompletableFuture$AsyncSupply.run(CompletableFuture.java:1590)
at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1142)
at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:617)
at java.lang.Thread.run(Thread.java:745)
主要活动：
package fr.aurelien.test_dessin_android;
import androidx.fragment.app.FragmentManager;
import androidx.fragment.app.FragmentTransaction;
import androidx.appcompat.app.AppCompatActivity;
import android.os.Bundle;
public class MainActivity extends AppCompatActivity {
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
FragmentManager fragmentManager = getSupportFragmentManager();
FragmentTransaction fragmentTransaction = fragmentManager.beginTransaction();
fragmentTransaction.add(R.id.frameLayout, new SimpleFragment());
fragmentTransaction.commit();
}
}
片段class：
package fr.aurelien.test_dessin_android;
import android.os.Bundle;
import androidx.annotation.NonNull;
import androidx.annotation.Nullable;
import androidx.fragment.app.Fragment;
import android.view.LayoutInflater;
import android.view.View;
import android.view.ViewGroup;
public class SimpleFragment extends Fragment {
@Nullable
@Override
public View onCreateView(@NonNull LayoutInflater inflater, @Nullable ViewGroup container, @Nullable Bundle savedInstanceState) {
View retView = inflater.inflate(R.layout.fragment_layout, container, false);
return retView;
}
}
Manifest.xml :
<?xml version="1.0" encoding="utf-8"?>
<manifest xmlns:android="http://schemas.android.com/apk/res/android"
package="fr.aurelien.test_dessin_android">
<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.default">
<activity android:name=".MainActivity">
<intent-filter>
<action android:name="android.intent.action.MAIN" />
<category android:name="android.intent.category.LAUNCHER" />
</intent-filter>
</activity>
</application>
</manifest>
XML 代码：
<?xml version="1.0" encoding="utf-8"?>
<androidx.constraintlayout.widget.ConstraintLayout 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">
<TextView
android:id="@+id/textView"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_marginStart="70dp"
android:layout_marginTop="16dp"
android:text="TextView"
app:layout_constraintStart_toStartOf="parent"
app:layout_constraintTop_toTopOf="parent" />
<ImageView
android:id="@+id/imageView"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_marginStart="55dp"
android:layout_marginTop="31dp"
app:layout_constraintStart_toStartOf="parent"
app:layout_constraintTop_toBottomOf="@+id/textView"
app:srcCompat="@mipmap/ic_launcher" />
<Button
android:id="@+id/button5"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_marginTop="16dp"
android:text="Button"
app:layout_constraintTop_toTopOf="parent"
tools:layout_editor_absoluteX="189dp" />
</androidx.constraintlayout.widget.ConstraintLayout>
您是否尝试过使用 androidx.appcompat.widget.AppCompatButton 而不是 Button？
这是 Android Studio 中的错误。您可以在此处跟踪它，它显然已针对 3.5.2 https://issuetracker.google.com/issues/132316448
修复如果您想使用 material 组件，您需要将 styles.xml 中的默认主题从 Theme.AppCompat 更改为 Theme.MaterialComponents.
不要忘记添加这个
implementation 'com.google.android.material:material:1.1.0' 在您的应用级别 build.gradle