Androidの疑難雜症之加載布局報Error inflating class

android.view.InflateException: Binary XML file line #12: Error inflating class <unknown>

出現這種錯誤有可能是，你的布局當中某個wedget的屬性出錯，比如引用了?attr/xxxx，但是你的主題里面卻沒有給這個attr賦值。

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
    android:id="@+id/llPlaceHolderLoading"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:layout_gravity="center"
    android:background="?attr/primary_page_background"
    android:gravity="center"
    android:orientation="vertical"
    android:visibility="visible" >

    <ProgressBar
        style="@style/AppTheme.Widget.Progress"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_marginBottom="8dp" />

    <TextView
        android:id="@+id/tvLoadTip"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_marginBottom="16dp"
        android:text="?attr/loading_tip"
        android:textColor="@color/progress_tips_text_color"
        android:textAppearance="?android:attr/textAppearanceMedium" />

</LinearLayout>

像這樣的在style里面沒有把attr賦值，這個界面是加載不錯來，並且報錯

02-03 17:24:50.746: E/AndroidRuntime(10702): java.lang.RuntimeException: Unable to start activity ComponentInfo{net.realtor.app.extranet.cmls/net.realtor.app.extranet.cmls.ui.activity.TestActivity}: android.view.InflateException: Binary XML file line #12: Error inflating class android.widget.ProgressBar