PercentFrameLayout: You must supply a layout_width attribute
问题 I try to use a PercentFrameLayout but I get this error message: Binary XML file line #: You must supply a layout_width attribute. This is the xml I use: <android.support.percent.PercentFrameLayout xmlns:android="http://schemas.android.com/apk/res/android" xmlns:app="http://schemas.android.com/apk/res-auto" android:layout_width="match_parent" android:layout_height="match_parent"> <ImageView app:layout_heightPercent="50%" app:layout_marginLeftPercent="25%" app:layout_marginTopPercent="25%" app