问题
I am new to Android Studio and I don't get why my toolbar isn't shown as described by https://developer.android.com/training/appbar/setting-up I know there are already some other questions like mine on stackoverflow but they don't work at my project. Therefore I would be very thankful for fixing this issue. Screenshot:
java.lang.ClassNotFoundException: android.view.View$OnUnhandledKeyEventListener
at org.jetbrains.android.uipreview.ModuleClassLoader.load(ModuleClassLoader.java:180)
at com.android.tools.idea.rendering.RenderClassLoader.findClass(RenderClassLoader.java:61)
at org.jetbrains.android.uipreview.ModuleClassLoader.findClass(ModuleClassLoader.java:118)
at java.lang.ClassLoader.loadClass(ClassLoader.java:424)
at java.lang.ClassLoader.loadClass(ClassLoader.java:357)
at org.jetbrains.android.uipreview.ModuleClassLoader.loadClass(ModuleClassLoader.java:213)
at android.support.v7.widget.ViewUtils.isLayoutRtl(ViewUtils.java:58)
at android.support.v7.widget.Toolbar.onMeasure_Original(Toolbar.java:1578)
at android.support.v7.widget.Toolbar.onMeasure(Toolbar.java)
at android.view.View.measure_Original(View.java:22071)
at android.view.View_Delegate.measure(View_Delegate.java:80)
at android.view.View.measure(View.java:22035)
at android.view.ViewGroup.measureChildWithMargins(ViewGroup.java:6602)
at android.widget.FrameLayout.onMeasure(FrameLayout.java:185)
at android.view.View.measure_Original(View.java:22071)
at android.view.View_Delegate.measure(View_Delegate.java:80)
at android.view.View.measure(View.java:22035)
at android.widget.RelativeLayout.measureChildHorizontal(RelativeLayout.java:715)
at android.widget.RelativeLayout.onMeasure(RelativeLayout.java:461)
at android.view.View.measure_Original(View.java:22071)
at android.view.View_Delegate.measure(View_Delegate.java:80)
at android.view.View.measure(View.java:22035)
at com.android.layoutlib.bridge.impl.RenderSessionImpl.measureView(RenderSessionImpl.java:590)
at com.android.layoutlib.bridge.impl.RenderSessionImpl.inflate(RenderSessionImpl.java:343)
at com.android.layoutlib.bridge.Bridge.createSession(Bridge.java:384)
at com.android.tools.idea.layoutlib.LayoutLibrary.createSession(LayoutLibrary.java:193)
at com.android.tools.idea.rendering.RenderTask.createRenderSession(RenderTask.java:544)
at com.android.tools.idea.rendering.RenderTask.lambda$inflate$3(RenderTask.java:678)
at java.util.concurrent.FutureTask.run(FutureTask.java:266)
at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1142)
at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:617)
at java.lang.Thread.run(Thread.java:745)
toolbar.xml
<?xml version="1.0" encoding="utf-8"?>
<android.support.v7.widget.Toolbar xmlns:android="http://schemas.android.com/apk/res/android"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:background="@color/colorPrimaryDark">
</android.support.v7.widget.Toolbar>
build.gradle (app level)
apply plugin: 'com.android.application'
android {
compileSdkVersion 28
defaultConfig {
applicationId "com.example.david.gamebase"
minSdkVersion 21
targetSdkVersion 28
versionCode 1
versionName "1.0"
testInstrumentationRunner "android.support.test.runner.AndroidJUnitRunner"
}
buildTypes {
release {
minifyEnabled false
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.google.firebase:firebase-auth:11.6.0'
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'
}
apply plugin: 'com.google.gms.google-services'
style.xml:
<resources>
<!-- Base application theme. -->
<style name="AppTheme" parent="Base.Theme.AppCompat.Light.DarkActionBar">
<!-- Customize your theme here. -->
<item name="colorPrimary">@color/colorPrimary</item>
<item name="colorPrimaryDark">@color/colorPrimaryDark</item>
<item name="colorAccent">@color/colorAccent</item>
</style>
</resources>
## toolbar.xml ##
<?xml version="1.0" encoding="utf-8"?>
<android.support.v7.widget.Toolbar xmlns:android="http://schemas.android.com/apk/res/android"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:background="@color/colorPrimaryDark">
</android.support.v7.widget.Toolbar>
回答1:
Make the changes in your build.gradle (app level) to downgrade to version 27 as below. Then sync and build project. Hopefully it will fix the issue..
compileSdkVersion 27
targetSdkVersion 27
implementation 'com.android.support:appcompat-v7:27.1.1'
回答2:
As mentioned by documentation, first, your Activity should be extend from AppCompatActivity().
Second, in your project styles, Base.Theme.AppCompat.Light.DarkActionBar is set which means it does have a DarkActionBar but you already have a Toolbar in your layout. So, simply, change:
Base.Theme.AppCompat.Light.DarkActionBar
to:
Theme.AppCompat.Light.NoActionBar
Then, (in java-kotlin side), setup the Toolbar:
// Note that the Toolbar defined in the layout has the id "my_toolbar"
setSupportActionBar(findViewById(R.id.my_toolbar))
And give the Toolbar an id.
<android.support.v7.widget.Toolbar
android:id="@+id/my_toolbar"
android:layout_width="match_parent"
android:layout_height="?attr/actionBarSize"
android:background="?attr/colorPrimary"
android:theme="@style/ThemeOverlay.AppCompat.ActionBar"
app:popupTheme="@style/ThemeOverlay.AppCompat.Light"/>
Then you should be good to go.
回答3:
It's not an error but a warning it can be ignored by the addition of the following code in my build.gradle (app level) the file works in my case. Then sync and build the project. Hopefully, it fixes the issue.
configurations.all {
resolutionStrategy.eachDependency { DependencyResolveDetails details ->
def requested = details.requested
if (requested.group == "com.android.support") {
if (!requested.name.startsWith("multidex")) {
details.useVersion "26.+"
}
}
}
}
Reference to the gist
回答4:
https://github.com/DonaldDu/FixUnhandledEvent
android.view.View$OnUnhandledKeyEventListener is add in api28.
If runtime device below 28, can't find the class, but run without fatal error.
We can inject the class in debug mode to ignore error message.
implementation 'com.android.support:appcompat-v7:28.0.0'
implementation "org.jetbrains.kotlin:kotlin-stdlib-jdk7:$kotlin_version"
//inject class when api<28 && debug==true
debugImplementation 'com.github.DonaldDu:FixUnhandledEvent:1.0'
回答5:
There's problem with library ~-v7:28.0.0. There are two solutions, your can either download compile and targetSdkVersion to 27 or upgrade Android Studio to latest version (3.2.x higher).
回答6:
Add multidex support library to your dependencies
com.android.support:multidex:1.0.3
回答7:
You can fix it easily,
implementation 'com.android.support:appcompat-v7:28.0.0-alpha1'
and Open style.xml under values and change to
style name="AppTheme" parent="Base.Theme.AppCompat.Light.DarkActionBar">
来源：https://stackoverflow.com/questions/51957944/android-view-viewonunhandledkeyeventlistener