android - 无法解析符号卡，Android Studio中的依赖性错误

我试图证明我的计划是正确的。我根据文档添加了依赖项，但仍然出现错误：“无法解析符号卡”、“无法解析符号卡头”。
主要活动：

 @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);

        if (savedInstanceState == null) {
            getFragmentManager().beginTransaction()
                    .add(R.id.container, new PlaceholderFragment())
                    .commit();
        }

        ArrayList<Card> cards = new ArrayList<Card>();
        //Create a Card
        Card card = new Card(getContext());

        //Create a CardHeader
        CardHeader header = new CardHeader(getContext());
        ....
        //Add Header to card
        card.addCardHeader(header);

        cards.add(card);

        CardArrayAdapter mCardArrayAdapter = new CardArrayAdapter(getActivity(),cards);

        CardListView listView = (CardListView) getActivity().findViewById(R.id.myList);
        if (listView!=null){
            listView.setAdapter(mCardArrayAdapter);
        }
    }

fragment_main.xml文件

<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=".MainActivity$PlaceholderFragment">

    <it.gmariotti.cardslib.library.view.CardListView
        android:layout_width="match_parent"
        android:layout_height="match_parent"
        android:id="@+id/myList"/>

</RelativeLayout>

平地

buildscript {
    repositories {
        mavenCentral()
    }
    dependencies {
        classpath 'com.android.tools.build:gradle:0.6.+'
    }
}
apply plugin: 'android'

repositories {
    mavenCentral()
}

android {
    compileSdkVersion 18
    buildToolsVersion "18.1.1"

    defaultConfig {
        minSdkVersion 14
        targetSdkVersion 18
    }
}

dependencies {
    compile 'com.github.gabrielemariotti.cards:library:0.6.0'
}

最佳答案

转到File -> Invalidate Caches，使android studio的缓存失效。这可能会解决问题。