android:主题在布局文件中不起作用

Question

根据 this :

Elements in XML layout definitions can specify the android:theme attribute, which references a theme resource. This attribute modifies the theme for the element and any child elements, which is useful for altering theme color palettes in a specific portion of an interface.

这意味着我们可以在布局文件中指定android:theme。另外，如果我们查看 Toolbar 的使用方式:

<?xml version="1.0" encoding="utf-8"?>
<android.support.v7.widget.Toolbar xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    android:id="@+id/toolbar"
    android:layout_width="match_parent"
    android:layout_height="wrap_content"
    android:background="@color/green"
    android:minHeight="?attr/actionBarSize"
    app:theme="@style/ThemeOverlay.AppCompat.ActionBar" />

很明显，添加了theme 支持。

现在我正在尝试这个:

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:orientation="vertical">

    <TextView
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:text="Test"
        android:theme="@style/TextViewTheme" />
</LinearLayout>

TextViewTheme 是:

<style name="TextViewTheme" parent="TextAppearance.AppCompat">
    <item name="android:textColor">#ff0000</item>
</style>

这在设计编辑器中看起来很完美，但在运行时我遇到了这个异常:

12-05 15:56:40.414  32501-32501/com.my.app E/AndroidRuntime﹕ FATAL EXCEPTION: main
    Process: com.my.app, PID: 32501
    java.lang.RuntimeException: Unable to start activity ComponentInfo{com.my.app/com.my.app.TabbedActivity}: android.view.InflateException: Binary XML file line #8: Error inflating class android.widget.TextView
            at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2298)
            at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:2360)
            at android.app.ActivityThread.access$800(ActivityThread.java:144)
            at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1278)
            at android.os.Handler.dispatchMessage(Handler.java:102)
            at android.os.Looper.loop(Looper.java:135)
            at android.app.ActivityThread.main(ActivityThread.java:5221)
            at java.lang.reflect.Method.invoke(Native Method)
            at java.lang.reflect.Method.invoke(Method.java:372)
            at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:899)
            at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:694)
     Caused by: android.view.InflateException: Binary XML file line #8: Error inflating class android.widget.TextView
            at android.view.LayoutInflater.createView(LayoutInflater.java:633)
            at com.android.internal.policy.impl.PhoneLayoutInflater.onCreateView(PhoneLayoutInflater.java:55)
            at android.view.LayoutInflater.onCreateView(LayoutInflater.java:682)
            at android.view.LayoutInflater.createViewFromTag(LayoutInflater.java:741)
            at android.view.LayoutInflater.rInflate(LayoutInflater.java:806)
            at android.view.LayoutInflater.inflate(LayoutInflater.java:504)
            at android.view.LayoutInflater.inflate(LayoutInflater.java:414)
            at com.my.app.ui.DrawerFragment.onCreateView(DrawerFragment.java:20)
            at android.support.v4.app.Fragment.performCreateView(Fragment.java:1786)
            at android.support.v4.app.FragmentManagerImpl.moveToState(FragmentManager.java:920)
            at android.support.v4.app.FragmentManagerImpl.moveToState(FragmentManager.java:1104)
            at android.support.v4.app.FragmentManagerImpl.addFragment(FragmentManager.java:1206)
            at android.support.v4.app.FragmentManagerImpl.onCreateView(FragmentManager.java:2159)
            at android.support.v4.app.FragmentActivity.onCreateView(FragmentActivity.java:297)
            at android.support.v7.app.ActionBarActivity.onCreateView(ActionBarActivity.java:547)
            at android.view.LayoutInflater.createViewFromTag(LayoutInflater.java:727)
            at android.view.LayoutInflater.rInflate(LayoutInflater.java:806)
            at android.view.LayoutInflater.rInflate(LayoutInflater.java:809)
            at android.view.LayoutInflater.inflate(LayoutInflater.java:504)
            at android.view.LayoutInflater.inflate(LayoutInflater.java:414)
            at android.view.LayoutInflater.inflate(LayoutInflater.java:365)
            at android.support.v7.app.ActionBarActivityDelegateBase.setContentView(ActionBarActivityDelegateBase.java:228)
            at android.support.v7.app.ActionBarActivity.setContentView(ActionBarActivity.java:102)
            at com.my.app.TabbedActivity.onCreate(TabbedActivity.java:40)
            at android.app.Activity.performCreate(Activity.java:5933)
            at android.app.Instrumentation.callActivityOnCreate(Instrumentation.java:1105)
            at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2251)
            at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:2360)
            at android.app.ActivityThread.access$800(ActivityThread.java:144)
            at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1278)
            at android.os.Handler.dispatchMessage(Handler.java:102)
            at android.os.Looper.loop(Looper.java:135)
            at android.app.ActivityThread.main(ActivityThread.java:5221)
            at java.lang.reflect.Method.invoke(Native Method)
            at java.lang.reflect.Method.invoke(Method.java:372)
            at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:899)
            at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:694)
     Caused by: java.lang.reflect.InvocationTargetException
            at java.lang.reflect.Constructor.newInstance(Native Method)
            at java.lang.reflect.Constructor.newInstance(Constructor.java:288)
            at android.view.LayoutInflater.createView(LayoutInflater.java:607)
            at com.android.internal.policy.impl.PhoneLayoutInflater.onCreateView(PhoneLayoutInflater.java:55)
            at android.view.LayoutInflater.onCreateView(LayoutInflater.java:682)
            at android.view.LayoutInflater.createViewFromTag(LayoutInflater.java:741)
            at android.view.LayoutInflater.rInflate(LayoutInflater.java:806)
            at android.view.LayoutInflater.inflate(LayoutInflater.java:504)
            at android.view.LayoutInflater.inflate(LayoutInflater.java:414)
            at com.my.app.ui.DrawerFragment.onCreateView(DrawerFragment.java:20)
            at android.support.v4.app.Fragment.performCreateView(Fragment.java:1786)
            at android.support.v4.app.FragmentManagerImpl.moveToState(FragmentManager.java:920)
            at android.support.v4.app.FragmentManagerImpl.moveToState(FragmentManager.java:1104)
            at android.support.v4.app.FragmentManagerImpl.addFragment(FragmentManager.java:1206)
            at android.support.v4.app.FragmentManagerImpl.onCreateView(FragmentManager.java:2159)
            at android.support.v4.app.FragmentActivity.onCreateView(FragmentActivity.java:297)
            at android.support.v7.app.ActionBarActivity.onCreateView(ActionBarActivity.java:547)
            at android.view.LayoutInflater.createViewFromTag(LayoutInflater.java:727)
            at android.view.LayoutInflater.rInflate(LayoutInflater.java:806)
            at android.view.LayoutInflater.rInflate(LayoutInflater.java:809)
            at android.view.LayoutInflater.inflate(LayoutInflater.java:504)
            at android.view.LayoutInflater.inflate(LayoutInflater.java:414)
            at android.view.LayoutInflater.inflate(LayoutInflater.java:365)
            at android.support.v7.app.ActionBarActivityDelegateBase.setContentView(ActionBarActivityDelegateBase.java:228)
            at android.support.v7.app.ActionBarActivity.setContentView(ActionBarActivity.java:102)
            at com.my.app.TabbedActivity.onCreate(TabbedActivity.java:40)
            at android.app.Activity.performCreate(Activity.java:5933)
            at android.app.Instrumentation.callActivityOnCreate(Instrumentation.java:1105)
            at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2251)
            at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:2360)
            at android.app.ActivityThread.access$800(ActivityThread.java:144)
            at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1278)
            at android.os.Handler.dispatchMessage(Handler.java:102)
            at android.os.Looper.loop(Looper.java:135)
            at android.app.ActivityThread.main(ActivityThread.java:5221)
            at java.lang.reflect.Method.invoke(Native Method)
            at java.lang.reflect.Method.invoke(Method.java:372)
            at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:899)
            at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:694)
     Caused by: java.lang.RuntimeException: Failed to resolve attribute at index 24
            at android.content.res.TypedArray.getColor(TypedArray.java:401)
            at android.widget.TextView.<init>(TextView.java:692)
            at android.widget.TextView.<init>(TextView.java:629)
            at android.widget.TextView.<init>(TextView.java:625)
            at java.lang.reflect.Constructor.newInstance(Native Method)
            at java.lang.reflect.Constructor.newInstance(Constructor.java:288)
            at android.view.LayoutInflater.createView(LayoutInflater.java:607)
            at com.android.internal.policy.impl.PhoneLayoutInflater.onCreateView(PhoneLayoutInflater.java:55)
            at android.view.LayoutInflater.onCreateView(LayoutInflater.java:682)
            at android.view.LayoutInflater.createViewFromTag(LayoutInflater.java:741)
            at android.view.LayoutInflater.rInflate(LayoutInflater.java:806)
            at android.view.LayoutInflater.inflate(LayoutInflater.java:504)
            at android.view.LayoutInflater.inflate(LayoutInflater.java:414)
            at com.my.app.ui.DrawerFragment.onCreateView(DrawerFragment.java:20)
            at android.support.v4.app.Fragment.performCreateView(Fragment.java:1786)
            at android.support.v4.app.FragmentManagerImpl.moveToState(FragmentManager.java:920)
            at android.support.v4.app.FragmentManagerImpl.moveToState(FragmentManager.java:1104)
            at android.support.v4.app.FragmentManagerImpl.addFragment(FragmentManager.java:1206)
            at android.support.v4.app.FragmentManagerImpl.onCreateView(FragmentManager.java:2159)
            at android.support.v4.app.FragmentActivity.onCreateView(FragmentActivity.java:297)
            at android.support.v7.app.ActionBarActivity.onCreateView(ActionBarActivity.java:547)
            at android.view.LayoutInflater.createViewFromTag(LayoutInflater.java:727)
            at android.view.LayoutInflater.rInflate(LayoutInflater.java:806)
            at android.view.LayoutInflater.rInflate(LayoutInflater.java:809)
            at android.view.LayoutInflater.inflate(LayoutInflater.java:504)
            at android.view.LayoutInflater.inflate(LayoutInflater.java:414)
            at android.view.LayoutInflater.inflate(LayoutInflater.java:365)
            at android.support.v7.app.ActionBarActivityDelegateBase.setContentView(ActionBarActivityDelegateBase.java:228)
            at android.support.v7.app.ActionBarActivity.setContentView(ActionBarActivity.java:102)
            at com.my.app.TabbedActivity.onCreate(TabbedActivity.java:40)
            at android.app.Activity.performCreate(Activity.java:5933)
            at android.app.Instrumentation.callActivityOnCreate(Instrumentation.java:1105)
            at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2251)
            at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:2360)
            at android.app.ActivityThread.access$800(ActivityThread.java:144)
            at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1278)
            at android.os.Handler.dispatchMessage(Handler.java:102)
            at android.os.Looper.loop(Looper.java:135)
            at android.app.ActivityThread.main(ActivityThread.java:5221)
            at java.lang.reflect.Method.invoke(Native Method)
            at java.lang.reflect.Method.invoke(Method.java:372)
            at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:899)
            at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:694)

此外，我查看了 Google IO app source code并且在布局文件中找不到任何 android:theme。我是不是误会了什么？

Answer 1

在 TextView 的情况下，您应该使用 android:theme="@style/TextViewTheme"style="@style/TextViewTheme"。

那是因为(来自 http://developer.android.com/guide/topics/ui/themes.html ):

A theme is a style applied to an entire Activity or application, rather than an individual View (as in the example above). When a style is applied as a theme, every View in the Activity or application will apply each style property that it supports. For example, you can apply the same CodeFont style as a theme for an Activity and then all text inside that Activity will have green monospace font.

我认为这个替换也可以解决您的问题。

如果您希望所有 TextView 看起来都一样，请尝试将它们的样式包含到 AppTheme 中，如下所示:

<!-- Application theme. -->
<style name="AppTheme" parent="AppBaseTheme">
    <item name="android:textViewStyle">@style/TextViewTheme</item>
</style>