Android Studio CardView错误:无法实例化 [英] Android Studio CardView error: could not be instantiated

问题描述

每当我在activity_main.xml中放入CardView时，都会出现此错误.

I get this error whenever I put a CardView in my activity_main.xml.

无法实例化以下类:

- android.support.v7.widget.CardView (打开类，显示异常，清除缓存)

- android.support.v7.widget.CardView (Open Class, Show Exception, Clear Cache)

我已将其添加到build.gradle中:

I've added this to the build.gradle :

    compile 'com.android.support:design:23.2.1'
    //CardView
    compile 'com.android.support:cardview-v7:25.0.0'
    //RecyclerView
    compile 'com.android.support:recyclerview-v7:25.0.0'

这是我的activity_main.xml

This is my activity_main.xml

<ScrollView xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    android:id="@+id/ScrollView01"
    android:layout_width="fill_parent"
    android:layout_height="fill_parent" >



    <LinearLayout 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="wrap_content"
        android:layout_height="wrap_content"
        tools:context="com.example.ivanp.meteostanica.TvrdjavaFragment"
        android:orientation="vertical"
        android:weightSum="1"
        >

        <ImageView
            android:layout_width="match_parent"
            android:layout_height="wrap_content"
            app:srcCompat="@drawable/bubanj"
            android:id="@+id/imageView8"
            android:adjustViewBounds="true" />


        <android.support.v7.widget.CardView
            xmlns:android="http://schemas.android.com/apk/res/android"
            xmlns:card_view="http://schemas.android.com/apk/res-auto"
            android:foreground="?android:attr/selectableItemBackground"
            android:clickable="true"
            android:layout_margin="40dp"
            android:id="@+id/card_view"
            android:layout_width="fill_parent"
            android:layout_height="250dp"
            card_view:cardCornerRadius="2dp">

            <TextView
                android:text="TextView"
                android:layout_width="match_parent"
                android:layout_height="wrap_content"
                android:id="@+id/textView" />

        </android.support.v7.widget.CardView>

    </LinearLayout>
</ScrollView>

推荐答案

万一它缺少样式，请在您的CardView中添加 style ="@ style/CardView" .

In case its about missing styles add style="@style/CardView" to your CardView.

这篇关于Android Studio CardView错误:无法实例化的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持IT屋！