我是 Android Studio 的新手。在 activity_main.xml 标签下,我遇到了这个问题。那么,如何解决呢?我已经离线安装了 Android Studio 1.4.1 包。另外,在 activity_main.xml 中,我无法将小部件拖放到手机上。但是,在 content_main.xml 中可以进行拖放。
Rendering Problems
The following classes could not be instantiated:
- android.support.design.widget.CoordinatorLayout (Open Class, Show Exception, Clear Cache)
- android.support.design.widget.AppBarLayout (Open Class, Show Exception, Clear Cache)
Tip: Use View.isInEditMode() in your custom views to skip code or show sample data when shown in the IDE
Exception Details
java.lang.IllegalArgumentException: You need to use a Theme.AppCompat theme (or descendant) with the design library.
at android.support.design.widget.ThemeUtils.checkAppCompatTheme(ThemeUtils.java:34)
at android.support.design.widget.CoordinatorLayout.<init>(CoordinatorLayout.java:178)
at android.support.design.widget.CoordinatorLayout.<init>(CoordinatorLayout.java:172)
at java.lang.reflect.Constructor.newInstance(Constructor.java:422)
at android.view.LayoutInflater.createViewFromTag(LayoutInflater.java:704)
at android.view.LayoutInflater.inflate(LayoutInflater.java:492)
at android.view.LayoutInflater.inflate(LayoutInflater.java:394)
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这里是我的activity_main.xml文本:
在这里放置XML代码
<?xml version="1.0" encoding="utf-8"?>
<android.support.design.widget.CoordinatorLayout
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="match_parent"
android:layout_height="match_parent" android:fitsSystemWindows="true"
tools:context=".MainActivity">
<android.support.design.widget.AppBarLayout android:layout_height="wrap_content"
android:layout_width="match_parent" android:theme="@style/AppTheme.AppBarOverlay">
<android.support.v7.widget.Toolbar android:id="@+id/toolbar"
android:layout_width="match_parent" android:layout_height="?attr/actionBarSize"
android:background="?attr/colorPrimary" app:popupTheme="@style/AppTheme.PopupOverlay" />
</android.support.design.widget.AppBarLayout>
<android.support.design.widget.FloatingActionButton android:id="@+id/fab"
android:layout_width="wrap_content" android:layout_height="wrap_content"
android:layout_gravity="bottom|end" android:layout_margin="@dimen/fab_margin"
android:src="@android:drawable/ic_dialog_email" />
</android.support.design.widget.CoordinatorLayout>