Android.View.WindowInSets类NotFoundException

Question

android.view.windowinsets是在API级别20中添加的。

我在我的CustomLayout中导入Android.view.WindowInsets并重写OnAppleWindowInsets(WindowInsetsInsets),但ClassNotFoundException出现在api级别从14到21的某些电话中。原因何在？

发生在：根Nexus 5,Android 4.4.2

堆栈跟踪：

Fatal Exception: java.lang.NoClassDefFoundError: android/view/WindowInsets
   at java.lang.Class.getDeclaredMethods(Class.java)
   at java.lang.Class.getDeclaredMethods(Class.java:656)
   at android.view.ViewDebug.getExportedPropertyMethods(ViewDebug.java:960)
   at android.view.ViewDebug.exportMethods(ViewDebug.java:1047)
   at android.view.ViewDebug.dumpViewProperties(ViewDebug.java:997)
   at android.view.ViewDebug.dumpViewProperties(ViewDebug.java:983)
   at android.view.ViewDebug.dumpView(ViewDebug.java:900)
   at android.view.ViewDebug.dumpViewHierarchy(ViewDebug.java:855)
   at android.view.ViewDebug.dumpViewHierarchy(ViewDebug.java:867)
   at android.view.ViewDebug.dumpViewHierarchy(ViewDebug.java:867)
   at android.view.ViewDebug.dumpViewHierarchy(ViewDebug.java:867)
   at android.view.ViewDebug.dumpViewHierarchy(ViewDebug.java:867)
   at android.view.ViewDebug.dumpViewHierarchy(ViewDebug.java:867)
   at android.view.ViewDebug.dumpViewHierarchy(ViewDebug.java:867)
   at android.view.ViewDebug.dump(ViewDebug.java:793)
   at android.view.ViewDebug.dispatchCommand(ViewDebug.java:416)
   at android.view.ViewRootImpl$W.executeCommand(ViewRootImpl.java:6258)
   at android.view.IWindow$Stub.onTransact(IWindow.java:65)
   at android.os.Binder.execTransact(Binder.java:404)
   at dalvik.system.NativeStart.run(NativeStart.java)
Caused by java.lang.ClassNotFoundException: Didn't find class "android.view.WindowInsets" on path: DexPathList[[zip file "/data/app/***-1.apk"],nativeLibraryDirectories=[/data/app-lib/***-1, /vendor/lib, /system/lib]]
   at dalvik.system.BaseDexClassLoader.findClass(BaseDexClassLoader.java:56)
   at java.lang.ClassLoader.loadClass(ClassLoader.java:497)
   at java.lang.ClassLoader.loadClass(ClassLoader.java:457)
   at java.lang.Class.getDeclaredMethods(Class.java)
   at java.lang.Class.getDeclaredMethods(Class.java:656)
   at android.view.ViewDebug.getExportedPropertyMethods(ViewDebug.java:960)
   at android.view.ViewDebug.exportMethods(ViewDebug.java:1047)
   at android.view.ViewDebug.dumpViewProperties(ViewDebug.java:997)
   at android.view.ViewDebug.dumpViewProperties(ViewDebug.java:983)
   at android.view.ViewDebug.dumpView(ViewDebug

Answer 1

系统遍历视图的所有公共方法，并遇到重写的onapplywindowinsetswithwindowinsets参数。系统中不存在此类型，因此发生崩溃。

Lollipop引入了view.onapplywindowinsets方法，但它也引入了onapplywindowinsetslistener，如果设置了该方法，将调用该方法，而不是前面提到的方法。

我在运行Android4.4的三星设备上有过这样的报道。

可以通过转储视图层次结构来触发。

到目前为止这还不能解决任何问题。support-v4库提供了帮助：

public class SampleView extends View {
    public SampleView(final Context context) {
        this(context, null);
    }

    public SampleView(final Context context, @Nullable final AttributeSet attrs) {
        this(context, attrs, 0);
    }

    public SampleView(final Context context, @Nullable final AttributeSet attrs, final int defStyleAttr) {
        super(context, attrs, defStyleAttr);

        ViewCompat.setOnApplyWindowInsetsListener(this, new android.support.v4.view.OnApplyWindowInsetsListener() {
            @Override
            public WindowInsetsCompat onApplyWindowInsets(final View v, final WindowInsetsCompat insets) {
                // Do whatever you needed to do in the first place...
                return insets.consumeSystemWindowInsets();
            }
        });
    }
}

在公共构造函数中使用上面的内容。WindowinSetsCompat是由support-v4库提供的，因此它始终存在，它不会直接在视图上公开任何不存在的未来类，并且该代码仅在Lollipop之后才有效（在Lollipop中引入了实际的WindowinSets)。