java Android无法使用attrs值膨胀布局文件
我正在开发一款可以在夜间模式和日间模式之间切换的应用程序 我用这些值创建了一个attrs文件
<?xml version="1.0" encoding="utf-8"?>
<resources>
<declare-styleable name="ds" >
<attr name="backgroundcolor" format="color"/>
<attr name="cardbackground" format="color"/>
<attr name="textcolor" format="color"/>
<attr name="tintcolor" format="color"/>
<attr name="buttoncolor" format="color"/>
</declare-styleable>
</resources>
和我制作了相应的两种样式，分别用于日间模式和夜间模式
<?xml version="1.0" encoding="utf-8"?>
<resources>
<!-- Base application theme. -->
<!-- Light Mode -->
<style name="AppTheme" parent="Theme.AppCompat.Light.DarkActionBar">
<!-- Customize your theme here. -->
<item name="colorPrimary">#2196F3</item>
<item name="colorPrimaryDark">#1976D2</item>
<item name="colorAccent">@color/colorAccent</item>
<item name="backgroundcolor">#fcfcfc</item>
<item name="cardbackground">#ffffff</item>
<item name="textcolor">#808080</item>
<item name="tintcolor">#000000</item>
<item name="buttoncolor">#2196F3</item>
</style>
<!-- Dark Mode -->
<style name="darktheme" parent="Theme.AppCompat.Light.DarkActionBar">
<!-- Customize your theme here. -->
<item name="colorPrimary">#212121</item>
<item name="colorPrimaryDark">#000000</item>
<item name="colorAccent">@color/colorAccent</item>
<item name="backgroundcolor">#303030</item>
<item name="cardbackground">#424242</item>
<item name="textcolor">#FFFFFF</item>
<item name="tintcolor">#FFFFFF</item>
<item name="buttoncolor">#2196F3</item>
</style>
</resources>
我在布局中添加了attrs值来代替background和textColor属性，以便在它们之间切换
这是布局文件
<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:安卓="http://schemas.安卓.com/apk/res/安卓"
xmlns:card_view="http://schemas.安卓.com/apk/res-auto"
安卓:orientation="vertical"
安卓:layout_width="match_parent"
安卓:minHeight="500dp"
安卓:layout_margin="5dp"
安卓:layout_height="match_parent"
安卓:background="?attr/backgroundcolor">
<安卓.support.v7.widget.CardView
安卓:id="@+id/card_view"
安卓:layout_gravity="center"
安卓:layout_width="match_parent"
安卓:layout_height="match_parent"
安卓:layout_margin="5dp"
card_view:cardCornerRadius="7dp"
card_view:contentPadding="10dp"
安卓:background="?attr/cardbackground">
<LinearLayout
安卓:layout_width="match_parent"
安卓:layout_height="match_parent"
安卓:orientation="vertical"
安卓:background="?attr/backgroundcolor">
<ImageView
安卓:id="@+id/imageView"
安卓:layout_width="match_parent"
安卓:layout_height="200dp"
安卓:src="@drawable/images"
安卓:scaleType="centerCrop"/>
<TextView
安卓:id="@+id/header"
安卓:layout_width="wrap_content"
安卓:padding="2dp"
安卓:text="Hello"
安卓:textColor="?attr/textcolor"
安卓:layout_height="wrap_content"
安卓:layout_marginTop="10dp"
安卓:textSize="18sp"
安卓:textStyle="bold" />
<TextView
安卓:id="@+id/mNews"
安卓:layout_width="wrap_content"
安卓:padding="2dp"
安卓:layout_height="wrap_content"
安卓:text="Asam"
安卓:layout_marginTop="10dp"
安卓:textSize="16sp"
安卓:textStyle="italic"
安卓:textColor="?attr/textcolor"/>
</LinearLayout>
</安卓.support.v7.widget.CardView>
</LinearLayout>
我正在实现一个ViewPager，其中我正在扩展布局文件，以前没有实现attrs它工作得很好，但现在在布局xml文件中使用attrs值时，它正在使应用程序崩溃
这是Viewpager适配器，在这里我正在膨胀布局文件
public class HorizontalPagerAdapter extends PagerAdapter {
String mResources[] = {"spider man description", "Iron man description", "batman description", "superman description"};
String mHeader[] = {"Spider-Man", "Iron Man", "BatMan", "Super Man"};
int mImages[] = {R.drawable.images, R.drawable.ironman, R.drawable.batman, R.drawable.super_man};
Context mContext;
LayoutInflater mLayoutInflater;
public HorizontalPagerAdapter(Context context) {
mContext = context;
mLayoutInflater = (LayoutInflater) mContext.getSystemService(Context.LAYOUT_INFLATER_SERVICE);
}
@Override
public int getCount() {
return mResources.length;
}
@Override
public boolean isViewFromObject(View view, Object object) {
return view == ((LinearLayout) object);
}
@Override
public Object instantiateItem(ViewGroup container, int position) {
View itemView = mLayoutInflater.inflate(R.layout.content_main, container, false);
TextView newsHeader = (TextView) itemView.findViewById(R.id.header);
TextView newsContent = (TextView) itemView.findViewById(R.id.mNews) ;
ImageView imageView = (ImageView) itemView.findViewById(R.id.imageView);
newsHeader.setText(mHeader[position]);
newsContent.setText(mResources[position]);
imageView.setImageResource(mImages[position]);
container.addView(itemView);
return itemView;
}
@Override
public void destroyItem(ViewGroup container, int position, Object object) {
container.removeView((LinearLayout) object);
}
}
因此，运行应用程序时会出现此错误
E/AndroidRuntime: FATAL EXCEPTION: main
Process: com.example.slimshady.newsreaderfinal, PID: 5440
安卓.view.InflateException: Binary XML file line #2: Binary XML file line #2: Error inflating class <unknown>
Caused by: 安卓.view.InflateException: Binary XML file line #2: Error inflating class <unknown>
Caused by: java.lang.reflect.InvocationTargetException
at java.lang.reflect.Constructor.newInstance0(Native Method)
at java.lang.reflect.Constructor.newInstance(Constructor.java:334)
at 安卓.view.LayoutInflater.createView(LayoutInflater.java:647)
at com.安卓.internal.policy.PhoneLayoutInflater.onCreateView(PhoneLayoutInflater.java:58)
at 安卓.view.LayoutInflater.onCreateView(LayoutInflater.java:720)
at 安卓.view.LayoutInflater.createViewFromTag(LayoutInflater.java:788)
at 安卓.view.LayoutInflater.createViewFromTag(LayoutInflater.java:730)
at 安卓.view.LayoutInflater.inflate(LayoutInflater.java:492)
at 安卓.view.LayoutInflater.inflate(LayoutInflater.java:423)
at com.example.slimshady.newsreaderfinal.HorizontalPagerAdapter.instantiateItem(HorizontalPagerAdapter.java:40)
at 安卓.support.v4.view.ViewPager.addNewItem(ViewPager.java:1010)
at 安卓.support.v4.view.ViewPager.populate(ViewPager.java:1158)
at 安卓.support.v4.view.ViewPager.populate(ViewPager.java:1092)
at 安卓.support.v4.view.ViewPager.onMeasure(ViewPager.java:1622)
at 安卓.view.View.measure(View.java:22071)
at 安卓.widget.RelativeLayout.measureChildHorizontal(RelativeLayout.java:715)
at 安卓.widget.RelativeLayout.onMeasure(RelativeLayout.java:461)
at 安卓.view.View.measure(View.java:22071)
at 安卓.support.v4.widget.DrawerLayout.onMeasure(DrawerLayout.java:1119)
at 安卓.view.View.measure(View.java:22071)
at 安卓.view.ViewGroup.measureChildWithMargins(ViewGroup.java:6602)
at 安卓.widget.FrameLayout.onMeasure(FrameLayout.java:185)
at 安卓.support.v7.widget.ContentFrameLayout.onMeasure(ContentFrameLayout.java:143)
at 安卓.view.View.measure(View.java:22071)
at 安卓.view.ViewGroup.measureChildWithMargins(ViewGroup.java:6602)
at 安卓.support.v7.widget.ActionBarOverlayLayout.onMeasure(ActionBarOverlayLayout.java:401)
at 安卓.view.View.measure(View.java:22071)
at 安卓.view.ViewGroup.measureChildWithMargins(ViewGroup.java:6602)
at 安卓.widget.FrameLayout.onMeasure(FrameLayout.java:185)
at 安卓.view.View.measure(View.java:22071)
at 安卓.view.ViewGroup.measureChildWithMargins(ViewGroup.java:6602)
at 安卓.widget.LinearLayout.measureChildBeforeLayout(LinearLayout.java:1514)
at 安卓.widget.LinearLayout.measureVertical(LinearLayout.java:806)
at 安卓.widget.LinearLayout.onMeasure(LinearLayout.java:685)
at 安卓.view.View.measure(View.java:22071)
at 安卓.view.ViewGroup.measureChildWithMargins(ViewGroup.java:6602)
at 安卓.widget.FrameLayout.onMeasure(FrameLayout.java:185)
at com.安卓.internal.policy.DecorView.onMeasure(DecorView.java:724)
at 安卓.view.View.measure(View.java:22071)
at 安卓.view.ViewRootImpl.performMeasure(ViewRootImpl.java:2422)
at 安卓.view.ViewRootImpl.measureHierarchy(ViewRootImpl.java:1504)
at 安卓.view.ViewRootImpl.performTraversals(ViewRootImpl.java:1761)
at 安卓.view.ViewRootImpl.doTraversal(ViewRootImpl.java:1392)
at 安卓.view.ViewRootImpl$TraversalRunnable.run(ViewRootImpl.java:6752)
at 安卓.view.Choreographer$CallbackRecord.run(Choreographer.java:911)
at 安卓.view.Choreographer.doCallbacks(Choreographer.java:723)
at 安卓.view.Choreographer.doFrame(Choreographer.java:658)
at 安卓.view.Choreographer$FrameDisplayEventReceiver.run(Choreographer.java:897)
at 安卓.os.Handler.handleCallback(Handler.java:790)
at 安卓.os.Handler.dispatchMessage(Handler.java:99)
at 安卓.os.Looper.loop(Looper.java:164)
at 安卓.app.ActivityThread.main(ActivityThread.java:6494)
at java.lang.reflect.Method.invoke(Native Method)
at com.安卓.internal.os.RuntimeInit$MethodAndArgsCaller.run(RuntimeInit.java:438)
at com.安卓.internal.os.ZygoteInit.main(ZygoteInit.java:807)
Caused by: java.lang.UnsupportedOperationException: Failed to resolve attribute at index 13: TypedValue{t=0x2/d=0x7f030036 a=-1}
at 安卓.content.res.TypedArray.getDrawableForDensity(TypedArray.java:944)
at 安卓.content.res.TypedArray.getDrawable(TypedArray.java:928)
at 安卓.view.View.<init>(View.java:4768)
at 安卓.view.ViewGroup.<init>(ViewGroup.java:597)
at 安卓.widget.LinearLayout.<init>(LinearLayout.java:234)
at 安卓.widget.LinearLayout.<init>(LinearLayout.java:230)
at 安卓.widget.LinearLayout.<init>(LinearLayout.java:226)
... 55 more
Application terminated.
我做错了什么？无法在线找到此问题的正确解决方案，因此我正在创建此线程
# 1 楼答案
膨胀
View时，相关属性和值将从LayoutInflater使用的Context上的Theme中提取。在这种情况下，传递给HorizontalPagerAdapter的Context显然没有正确的Theme，如Failed to resolve attribute消息所示当应用程序
Context用于创建UI组件时，通常会发生这种情况。默认情况下，应用程序Context实际上没有附加Theme，即使在清单的<application>元素上指定了一个android:theme。这只是为Activity类设置一个默认的Theme通常，您只想使用当前的
Activity作为与View相关的任何内容的Context，事实上，这就是这里的解决方案。Activity将附加相应的Theme，然后在Adapter中膨胀这些页面时，您的自定义属性将正确解析# 2 楼答案
不要使用样式表，创建其他样式。在新值目录中创建xml，并使用更改的值创建AppTheme的另一个副本
Full guide