这是我的build.gradle：

apply plugin: 'com.android.application'
 
android {
    compileSdkVersion 'android-L'
    buildToolsVersion "20.0.0"
 
    defaultConfig {
        applicationId "com.tod.android.lpreviewtest"
        minSdkVersion 'L'
        targetSdkVersion 'L'
        versionCode 1
        versionName "1.0"
    }
    buildTypes {
        release {
            runProguard false
            proguardFiles getDefaultProguardFile('proguard-android.txt'),'proguard-rules.pro'
        }
    }
}
 
dependencies {
    compile fileTree(dir: 'libs',include: ['*.jar'])
    compile 'com.android.support:cardview-v7:+'
}

现在我的布局：

<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:paddingLeft="@dimen/activity_horizontal_margin"
    android:paddingRight="@dimen/activity_horizontal_margin"
    android:paddingTop="@dimen/activity_vertical_margin"
    android:paddingBottom="@dimen/activity_vertical_margin"
    tools:context=".MyActivity">
    <android.support.v7.widget.CardView
        xmlns:card_view="http://schemas.android.com/apk/res-auto"
        android:id="@+id/card_view"
        android:layout_gravity="center"
        android:layout_width="200dp"
        android:layout_height="200dp"
        card_view:cardCornerRadius="4dp">
 
        <TextView
            android:id="@+id/info_text"
            android:layout_width="match_parent"
            android:layout_height="match_parent" />
    </android.support.v7.widget.CardView>
</RelativeLayout>

当我在android studio中切换到屏幕预览时,我得到一个渲染错误：

Rendering Problems The following classes could not be instantiated:
-android.support.v7.widget.CardView (Open Class,Show Exception)
 
Exception Details java.lang.ClassFormatError: Illegal field name "CardView.Dark"         
in class android/support/v7/cardview/R$style  at
java.lang.ClassLoader.defineClass1(ClassLoader.java:-2) at
java.lang.ClassLoader.defineClass(ClassLoader.java:792) at 
java.lang.ClassLoader.defineClass(ClassLoader.java:635) at 
java.lang.ClassLoader.loadClass(ClassLoader.java:424) at 
java.lang.ClassLoader.loadClass(ClassLoader.java:411) at 
java.lang.ClassLoader.loadClass(ClassLoader.java:357) at 
android.support.v7.widget.CardView.initialize(CardView.java:69) at 
android.support.v7.widget.CardView.<init>(CardView.java:60) at 
java.lang.reflect.Constructor.newInstance(Constructor.java:526) at 
android.view.LayoutInflater.rInflate_Original(LayoutInflater.java:802) at 
android.view.LayoutInflater_Delegate.rInflate(LayoutInflater_Delegate.java:64) at 
android.view.LayoutInflater.rInflate(LayoutInflater.java:778) at 
android.view.LayoutInflater.inflate(LayoutInflater.java:500) at 
android.view.LayoutInflater.inflate(LayoutInflater.java:381)

我尝试忽略错误,并在avd中运行该应用程序,而一切编译正常,布局中不会显示卡片视图.请帮忙！

附：我正在使用新的Android Studio beta 0.8.0