使用Material风格的CardView如果不指定主题就会报错，其实是Material库版本的问题，据说是升级到1.1.0之后，在使用MarterialCardView控件的时候，需要加上一个属性：android:theme="@style/Theme.MaterialComponents"，表示用的是Material主题的，使用在默认情况下，都是使用AppCompat这个主题的。所以加上这个属性就解决了，具体看下面的代码：
报错详情：
2022-02-05 14:34:36.377 23284-23284/? E/om.xw.sunnyfas: Unknown bits set in runtime_flags: 0x8000
2022-02-05 14:34:36.337 782-23292/? D/keymaster_worker: Keystore worker thread update function is invoked
2022-02-05 14:34:36.406 23284-23284/? E/libc: Access denied finding property "runtime.mmitest.isrunning"
2022-02-05 14:34:36.377 23284-23284/? E/om.xw.sunnyfas: Unknown bits set in runtime_flags: 0x8000
2022-02-05 14:34:36.377 23284-23284/? E/om.xw.sunnyfas: Unknown bits set in runtime_flags: 0x8000
2022-02-05 14:34:36.406 23284-23284/? E/libc: Access denied finding property "runtime.mmitest.isrunning"
2022-02-05 14:34:36.406 23284-23284/? E/libc: Access denied finding property "runtime.mmitest.isrunning"
2022-02-05 14:34:36.861 23284-23396/com.xw.sunnyfast E/AwareLog: AtomicFileUtils: readFileLines file not exist: android.util.AtomicFile@e322460
2022-02-05 14:34:36.862 23284-23396/com.xw.sunnyfast E/AwareLog: AtomicFileUtils: readFileLines file not exist: android.util.AtomicFile@4aeed19
2022-02-05 14:34:42.469 23284-23284/com.xw.sunnyfast E/AndroidRuntime: FATAL EXCEPTION: main
Process: com.xw.sunnyfast, PID: 23284
java.lang.RuntimeException: Unable to start activity ComponentInfo{com.xw.sunnyfast/com.xw.sunnyfast.ui.WeatherActivity}: android.view.InflateException: Binary XML file line #30 in com.xw.sunnyfast:layout/activity_weather: Binary XML file line #8 in com.xw.sunnyfast:layout/life_index: Error inflating class com.google.android.material.card.MaterialCardView
at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:3782)
at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:3961)
at android.app.servertransaction.LaunchActivityItem.execute(LaunchActivityItem.java:91)
at android.app.servertransaction.TransactionExecutor.executeCallbacks(TransactionExecutor.java:149)
at android.app.servertransaction.TransactionExecutor.execute(TransactionExecutor.java:103)
at android.app.ActivityThread$H.handleMessage(ActivityThread.java:2386)
at android.os.Handler.dispatchMessage(Handler.java:107)
at android.os.Looper.loop(Looper.java:213)
at android.app.ActivityThread.main(ActivityThread.java:8178)
at java.lang.reflect.Method.invoke(Native Method)
at com.android.internal.os.RuntimeInit$MethodAndArgsCaller.run(RuntimeInit.java:513)
at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:1101)
Caused by: android.view.InflateException: Binary XML file line #30 in com.xw.sunnyfast:layout/activity_weather: Binary XML file line #8 in com.xw.sunnyfast:layout/life_index: Error inflating class com.google.android.material.card.MaterialCardView
Caused by: android.view.InflateException: Binary XML file line #8 in com.xw.sunnyfast:layout/life_index: Error inflating class com.google.android.material.card.MaterialCardView
Caused by: java.lang.reflect.InvocationTargetException
at java.lang.reflect.Constructor.newInstance0(Native Method)
at java.lang.reflect.Constructor.newInstance(Constructor.java:343)
at android.view.LayoutInflater.createView(LayoutInflater.java:864)
at android.view.LayoutInflater.createViewFromTag(LayoutInflater.java:1016)
at android.view.LayoutInflater.parseInclude(LayoutInflater.java:1243)
at android.view.LayoutInflater.rInflate(LayoutInflater.java:1129)
at android.view.LayoutInflater.rInflateChildren(LayoutInflater.java:1094)
at android.view.LayoutInflater.rInflate(LayoutInflater.java:1136)
at android.view.LayoutInflater.rInflateChildren(LayoutInflater.java:1094)
at android.view.LayoutInflater.rInflate(LayoutInflater.java:1136)
at android.view.LayoutInflater.rInflateChildren(LayoutInflater.java:1094)
at android.view.LayoutInflater.rInflate(LayoutInflater.java:1136)
at android.view.LayoutInflater.rInflateChildren(LayoutInflater.java:1094)
at android.view.LayoutInflater.inflate(LayoutInflater.java:692)
at android.view.LayoutInflater.inflate(LayoutInflater.java:536)
at android.view.LayoutInflater.inflate(LayoutInflater.java:483)
at androidx.appcompat.app.AppCompatDelegateImpl.setContentView(AppCompatDelegateImpl.java:699)
at androidx.appcompat.app.AppCompatActivity.setContentView(AppCompatActivity.java:195)
at com.xw.sunnyfast.ui.WeatherActivity.onCreate(WeatherActivity.kt:31)
at android.app.Activity.performCreate(Activity.java:8086)
at android.app.Activity.performCreate(Activity.java:8074)
at android.app.Instrumentation.callActivityOnCreate(Instrumentation.java:1313)
at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:3755)
at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:3961)
at android.app.servertransaction.LaunchActivityItem.execute(LaunchActivityItem.java:91)
at android.app.servertransaction.TransactionExecutor.executeCallbacks(TransactionExecutor.java:149)
at android.app.servertransaction.TransactionExecutor.execute(TransactionExecutor.java:103)
at android.app.ActivityThread$H.handleMessage(ActivityThread.java:2386)
at android.os.Handler.dispatchMessage(Handler.java:107)
at android.os.Looper.loop(Looper.java:213)
at android.app.ActivityThread.main(ActivityThread.java:8178)
2022-02-05 14:34:42.469 23284-23284/com.xw.sunnyfast E/AndroidRuntime: at java.lang.reflect.Method.invoke(Native Method)
at com.android.internal.os.RuntimeInit$MethodAndArgsCaller.run(RuntimeInit.java:513)
at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:1101)
Caused by: java.lang.IllegalArgumentException: The style on this component requires your app theme to be Theme.MaterialComponents (or a descendant).
at com.google.android.material.internal.ThemeEnforcement.checkTheme(ThemeEnforcement.java:243)
at com.google.android.material.internal.ThemeEnforcement.checkMaterialTheme(ThemeEnforcement.java:217)
at com.google.android.material.internal.ThemeEnforcement.checkCompatibleTheme(ThemeEnforcement.java:145)
at com.google.android.material.internal.ThemeEnforcement.obtainStyledAttributes(ThemeEnforcement.java:76)
at com.google.android.material.card.MaterialCardView.<init>(MaterialCardView.java:124)
at com.google.android.material.card.MaterialCardView.<init>(MaterialCardView.java:114)
... 34 more
指定Materail风格的白色主题：
android:theme="@style/Theme.MaterialComponents.Light"完整布局文件：
<?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"
android:theme="@style/Theme.MaterialComponents.Light"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:layout_margin="15dp"
app:cardCornerRadius="4dp">
<LinearLayout
android:orientation="vertical"
android:layout_width="match_parent"
android:layout_height="wrap_content">
<TextView
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_marginStart="15dp"
android:layout_marginTop="20dp"
android:text="生活指数"
android:textColor="?android:attr/textColorPrimary"
android:textSize="20sp"/>
<LinearLayout
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:layout_marginTop="20dp">
<RelativeLayout
android:layout_width="0dp"
android:layout_height="60dp"
android:layout_weight="1">
<ImageView
android:id="@+id/coldRiskImg"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_centerVertical="true"
android:layout_marginStart="20dp"
android:src="@drawable/ic_coldrisk" />
<LinearLayout
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_centerVertical="true"
android:layout_toEndOf="@id/coldRiskImg"
android:layout_marginStart="20dp"
android:orientation="vertical">
<TextView
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:textSize="12sp"
android:text="感冒" />
<TextView
android:id="@+id/coldRiskText"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_marginTop="4dp"
android:textSize="16sp"
android:textColor="?android:attr/textColorPrimary" />
</LinearLayout>
</RelativeLayout>
<RelativeLayout
android:layout_width="0dp"
android:layout_height="60dp"
android:layout_weight="1">
<ImageView
android:id="@+id/dressingImg"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_centerVertical="true"
android:layout_marginStart="20dp"
android:src="@drawable/ic_dressing" />
<LinearLayout
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_centerVertical="true"
android:layout_toEndOf="@id/dressingImg"
android:layout_marginStart="20dp"
android:orientation="vertical">
<TextView
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:textSize="12sp"
android:text="穿衣" />
<TextView
android:id="@+id/dressingText"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_marginTop="4dp"
android:textSize="16sp"
android:textColor="?android:attr/textColorPrimary" />
</LinearLayout>
</RelativeLayout>
</LinearLayout>
<LinearLayout
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:layout_marginBottom="20dp">
<RelativeLayout
android:layout_width="0dp"
android:layout_height="60dp"
android:layout_weight="1">
<ImageView
android:id="@+id/ultravioletImg"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_centerVertical="true"
android:layout_marginStart="20dp"
android:src="@drawable/ic_ultraviolet" />
<LinearLayout
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_centerInParent="true"
android:layout_toEndOf="@id/ultravioletImg"
android:layout_marginStart="20dp"
android:orientation="vertical">
<TextView
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:textSize="12sp"
android:text="实时紫外线" />
<TextView
android:id="@+id/ultravioletText"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_marginTop="4dp"
android:textSize="16sp"
android:textColor="?android:attr/textColorPrimary" />
</LinearLayout>
</RelativeLayout>
<RelativeLayout
android:layout_width="0dp"
android:layout_height="60dp"
android:layout_weight="1">
<ImageView
android:id="@+id/carWashingImg"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_centerVertical="true"
android:layout_marginStart="20dp"
android:src="@drawable/ic_carwashing" />
<LinearLayout
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_centerInParent="true"
android:layout_toEndOf="@id/carWashingImg"
android:layout_marginStart="20dp"
android:orientation="vertical">
<TextView
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:textSize="12sp"
android:text="洗车" />
<TextView
android:id="@+id/carWashingText"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_marginTop="4dp"
android:textSize="16sp"
android:textColor="?android:attr/textColorPrimary" />
</LinearLayout>
</RelativeLayout>
</LinearLayout>
</LinearLayout>
</com.google.android.material.card.MaterialCardView>效果：
?
感谢：原文链接：https://blog.csdn.net/qq_22488067/article/details/106338577