錯誤充氣類Android中的按鈕

Question

我有一個應用程序與最低sdk 16至23我想盡可能使用材料設計。它也必須是全屏應用程序。包括AppCompat支持庫。現在我已經登錄活動有一些按鈕：

<Button 
    android:id="@+id/act_logon_btn_logon" 
    style="@style/ButtonDefault" 
    android:layout_width="match_parent" 
    android:layout_height="wrap_content" 
    android:text="@string/act_logon_logon" /> 

樣式如下（價值觀/ styles.xml）：

<style name="Theme.AppCompat.Light.NoActionBar.FullScreen" parent="@style/Theme.AppCompat.Light"> 
    <item name="windowNoTitle">true</item> 
    <item name="windowActionBar">false</item> 
    <item name="android:windowFullscreen">true</item> 
    <item name="android:windowContentOverlay">@null</item> 
</style> 

<style name="AppThemeBase" parent="Theme.AppCompat.Light.NoActionBar.FullScreen"></style> 

<style name="AppTheme" parent="AppThemeBase"></style> 

<style name="ButtonDefault" parent="Widget.AppCompat.Button"> 
    <item name="android:textSize">?attr/font_medium</item> 
</style> 

<style name="FontStyle"></style> 

<style name="FontStyle.Small"> 
    <item name="font_small">12sp</item> 
    <item name="font_medium">14sp</item> 
    <item name="font_large">16sp</item> 
</style> 

<style name="FontStyle.Medium"> 
    <item name="font_small">16sp</item> 
    <item name="font_medium">18sp</item> 
    <item name="font_large">20sp</item> 
</style> 

<style name="FontStyle.Large"> 
    <item name="font_small">20sp</item> 
    <item name="font_medium">22sp</item> 
    <item name="font_large">24sp</item> 
</style> 

和價值/ ATTRS：

<declare-styleable name="FontStyle"> 
    <attr name="font_small" format="dimension" /> 
    <attr name="font_medium" format="dimension" /> 
    <attr name="font_large" format="dimension" /> 
</declare-styleable> 

屬性font_medium的定義如here所述。我不明白的行爲是，當登錄活動被打開時，一切正常，沒有例外。但是當我從內部帶有片段的登錄活動中打開另一個活動，並且片段中有一個帶有此樣式的按鈕時，我會收到一個異常，指出「錯誤膨脹類按鈕」。當我從ButtonDefault樣式中刪除textSize屬性時，一切正常。爲什麼它在某個地方和某個地方工作？自定義屬性有問題嗎？

我試過用這種風格創建values-v21/styles.xml，但沒有效果。

您是否也可以解釋以下父類型定義之間的區別？我迷路了。

parent="Widget.AppCompat.Button" 
parent="@style/Widget.AppCompat.Button" 
parent="android:Widget.Button" 
parent="android:Widget.AppCompat.Button" 
parent="android:Widget.Material.Button" 
parent="android:style/Widget.Material.Button" 

謝謝。

編輯1 - 例外：

12-17 10:56:53.950: E/AndroidRuntime(7251): FATAL EXCEPTION: main 
12-17 10:56:53.950: E/AndroidRuntime(7251): Process: test.android, PID: 7251 
12-17 10:56:53.950: E/AndroidRuntime(7251): java.lang.RuntimeException: Unable to start activity ComponentInfo{test.dci.android/test.dci.android.view.activity.TransactionActivity}: android.view.InflateException: Binary XML file line #49: Error inflating class Button 
12-17 10:56:53.950: E/AndroidRuntime(7251):  at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2702) 
12-17 10:56:53.950: E/AndroidRuntime(7251):  at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:2767) 
12-17 10:56:53.950: E/AndroidRuntime(7251):  at android.app.ActivityThread.access$900(ActivityThread.java:177) 
12-17 10:56:53.950: E/AndroidRuntime(7251):  at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1449) 
12-17 10:56:53.950: E/AndroidRuntime(7251):  at android.os.Handler.dispatchMessage(Handler.java:102) 
12-17 10:56:53.950: E/AndroidRuntime(7251):  at android.os.Looper.loop(Looper.java:145) 
12-17 10:56:53.950: E/AndroidRuntime(7251):  at android.app.ActivityThread.main(ActivityThread.java:5951) 
12-17 10:56:53.950: E/AndroidRuntime(7251):  at java.lang.reflect.Method.invoke(Native Method) 
12-17 10:56:53.950: E/AndroidRuntime(7251):  at java.lang.reflect.Method.invoke(Method.java:372) 
12-17 10:56:53.950: E/AndroidRuntime(7251):  at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:1400) 
12-17 10:56:53.950: E/AndroidRuntime(7251):  at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:1195) 
12-17 10:56:53.950: E/AndroidRuntime(7251): Caused by: android.view.InflateException: Binary XML file line #49: Error inflating class Button 
12-17 10:56:53.950: E/AndroidRuntime(7251):  at android.view.LayoutInflater.createViewFromTag(LayoutInflater.java:770) 
12-17 10:56:53.950: E/AndroidRuntime(7251):  at android.view.LayoutInflater.rInflate(LayoutInflater.java:813) 
12-17 10:56:53.950: E/AndroidRuntime(7251):  at android.view.LayoutInflater.rInflate(LayoutInflater.java:821) 
12-17 10:56:53.950: E/AndroidRuntime(7251):  at android.view.LayoutInflater.inflate(LayoutInflater.java:511) 
12-17 10:56:53.950: E/AndroidRuntime(7251):  at android.view.LayoutInflater.inflate(LayoutInflater.java:415) 
12-17 10:56:53.950: E/AndroidRuntime(7251):  at test.dci.android.view.fragment.TransactionFragment.onCreateView(TransactionFragment.java:71) 
12-17 10:56:53.950: E/AndroidRuntime(7251):  at android.support.v4.app.Fragment.performCreateView(Fragment.java:1962) 
12-17 10:56:53.950: E/AndroidRuntime(7251):  at android.support.v4.app.FragmentManagerImpl.moveToState(FragmentManager.java:1036) 
12-17 10:56:53.950: E/AndroidRuntime(7251):  at android.support.v4.app.FragmentManagerImpl.moveToState(FragmentManager.java:1226) 
12-17 10:56:53.950: E/AndroidRuntime(7251):  at android.support.v4.app.FragmentManagerImpl.addFragment(FragmentManager.java:1328) 
12-17 10:56:53.950: E/AndroidRuntime(7251):  at android.support.v4.app.FragmentManagerImpl.onCreateView(FragmentManager.java:2284) 
12-17 10:56:53.950: E/AndroidRuntime(7251):  at android.support.v4.app.FragmentController.onCreateView(FragmentController.java:111) 
12-17 10:56:53.950: E/AndroidRuntime(7251):  at android.support.v4.app.FragmentActivity.dispatchFragmentsOnCreateView(FragmentActivity.java:314) 
12-17 10:56:53.950: E/AndroidRuntime(7251):  at android.support.v4.app.BaseFragmentActivityHoneycomb.onCreateView(BaseFragmentActivityHoneycomb.java:31) 
12-17 10:56:53.950: E/AndroidRuntime(7251):  at android.support.v4.app.FragmentActivity.onCreateView(FragmentActivity.java:79) 
12-17 10:56:53.950: E/AndroidRuntime(7251):  at test.dci.android.view.activity.TransactionActivity.onCreateView(TransactionActivity.java:1) 
12-17 10:56:53.950: E/AndroidRuntime(7251):  at android.view.LayoutInflater.createViewFromTag(LayoutInflater.java:740) 
12-17 10:56:53.950: E/AndroidRuntime(7251):  at android.view.LayoutInflater.rInflate(LayoutInflater.java:813) 
12-17 10:56:53.950: E/AndroidRuntime(7251):  at android.view.LayoutInflater.inflate(LayoutInflater.java:511) 
12-17 10:56:53.950: E/AndroidRuntime(7251):  at android.view.LayoutInflater.inflate(LayoutInflater.java:415) 
12-17 10:56:53.950: E/AndroidRuntime(7251):  at android.view.LayoutInflater.inflate(LayoutInflater.java:366) 
12-17 10:56:53.950: E/AndroidRuntime(7251):  at android.support.v7.app.AppCompatDelegateImplV7.setContentView(AppCompatDelegateImplV7.java:256) 
12-17 10:56:53.950: E/AndroidRuntime(7251):  at android.support.v7.app.AppCompatActivity.setContentView(AppCompatActivity.java:109) 
12-17 10:56:53.950: E/AndroidRuntime(7251):  at test.dci.android.view.activity.TransactionActivity.onCreate(TransactionActivity.java:31) 
12-17 10:56:53.950: E/AndroidRuntime(7251):  at android.app.Activity.performCreate(Activity.java:6289) 
12-17 10:56:53.950: E/AndroidRuntime(7251):  at android.app.Instrumentation.callActivityOnCreate(Instrumentation.java:1119) 
12-17 10:56:53.950: E/AndroidRuntime(7251):  at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2655) 
12-17 10:56:53.950: E/AndroidRuntime(7251):  ... 10 more 
12-17 10:56:53.950: E/AndroidRuntime(7251): Caused by: java.lang.RuntimeException: Failed to resolve attribute at index 12 
12-17 10:56:53.950: E/AndroidRuntime(7251):  at android.content.res.TypedArray.getDimensionPixelSize(TypedArray.java:582) 
12-17 10:56:53.950: E/AndroidRuntime(7251):  at android.widget.TextView.<init>(TextView.java:1400) 
12-17 10:56:53.950: E/AndroidRuntime(7251):  at android.widget.Button.<init>(Button.java:115) 
12-17 10:56:53.950: E/AndroidRuntime(7251):  at android.widget.Button.<init>(Button.java:108) 
12-17 10:56:53.950: E/AndroidRuntime(7251):  at android.support.v7.widget.AppCompatButton.<init>(AppCompatButton.java:62) 
12-17 10:56:53.950: E/AndroidRuntime(7251):  at android.support.v7.widget.AppCompatButton.<init>(AppCompatButton.java:58) 
12-17 10:56:53.950: E/AndroidRuntime(7251):  at android.support.v7.app.AppCompatViewInflater.createView(AppCompatViewInflater.java:98) 
12-17 10:56:53.950: E/AndroidRuntime(7251):  at android.support.v7.app.AppCompatDelegateImplV7.createView(AppCompatDelegateImplV7.java:938) 
12-17 10:56:53.950: E/AndroidRuntime(7251):  at android.support.v7.app.AppCompatDelegateImplV7.onCreateView(AppCompatDelegateImplV7.java:992) 
12-17 10:56:53.950: E/AndroidRuntime(7251):  at 

Answer 1

已解決。問題在於，inflater的屬性是未知的（或未指定）。解決方案是在使用屬性的視圖膨脹之前定義屬性值！

解決方案1：具有此屬性的樣式不僅必須在活動中指定，還必須在具有此屬性的某些視圖的片段中指定。所以前加入這一行片段的onCreateView()該膨脹片段的根視圖行：

getContext().getTheme().applyStyle(fontStyleResId, true); 

解決方案2：

<style name="AppThemeBase" parent="Theme.AppCompat.Light.NoActionBar.FullScreen"> 
    <item name="font_small">@dimen/font_size_medium_small</item> 
    <item name="font_medium">@dimen/font_size_medium_medium</item> 
    <item name="font_large">@dimen/font_size_medium_large</item> 
</style> 

Answer 2

正如我們在評論部分討論的，問題是，充氣不知何故未能識別?attr/font_medium，從而提高異常。

您可以使用dimens.xml文件指定自定義尺寸，像這樣：

<resources> 
    <dimen name="small">14sp</dimen> 
    <dimen name="medium">16sp</dimen> 
    <dimen name="large">18sp</dimen> 
</resources> 

，然後在styles.xml你指的這些值是這樣的：

<style name="ButtonDefault" parent="Widget.AppCompat.Button"> 
    <item name="android:textSize">@dimen/medium</item> 
</style> 

由於每個其他資源，dimens.xml都可以放置在相應的資源文件夾中以適應特定的設備配置（屏幕尺寸，密度，語言等）。