android view如何获取DecorView

要获取DecorView，可以通过以下步骤：

1. 首先获取当前Activity的Window对象，可以调用Activity的getWindow()方法来获取。

2. 然后调用Window对象的getDecorView()方法即可获取到DecorView。

示例代码：

// 获取当前Activity的Window对象
Window window = getWindow();
// 获取DecorView
View decorView = window.getDecorView();

值得注意的是，获取到DecorView后，可以通过它来获取整个屏幕的大小，以及设置全屏等操作。但是建议在开发中尽量避免直接对DecorView进行操作，以免影响系统UI的正常显示。

相关问题

Activity 中怎么获取DecorView

在Android应用程序的Activity中，你可以通过Activity类的`getWindow()`方法获取到对应的`Window`对象，然后调用`getWindow().getDecorView()`来获取DecorView。DecorView是Activity的根视图，包含了所有其他可见组件。这是一个典型的示例：

View decorView = getApplicationContext().getSystemService(Context.WINDOW_SERVICE)
        .getDecorView();

或者如果你是在Activity内部获取：

Window window = this.getWindow();
decorView = window.getDecorView();

不过，一般在实际开发中，除非有特殊需求，否则直接操作DecorView的情况并不多见，因为大多数时候我们会在更上层的ViewGroup（如`LinearLayout`, `CoordinatorLayout`等）或者Fragment里面进行布局管理和事件处理。

E/AndroidRuntime: FATAL EXCEPTION: main Process: com.example.hjschoolhelper210301201_1, PID: 13135 java.lang.NullPointerException: Attempt to invoke virtual method 'void android.widget.TextView.setText(java.lang.CharSequence)' on a null object reference at com.example.hjschoolhelper210301201_1.ClubinfoAdpter.getView(ClubinfoAdpter.java:44) at android.widget.AbsListView.obtainView(AbsListView.java:2458) at android.widget.ListView.makeAndAddView(ListView.java:2067) at android.widget.ListView.fillDown(ListView.java:793) at android.widget.ListView.fillFromTop(ListView.java:855) at android.widget.ListView.layoutChildren(ListView.java:1838) at android.widget.AbsListView.onLayout(AbsListView.java:2255) at android.view.View.layout(View.java:23693) at android.view.ViewGroup.layout(ViewGroup.java:6413) at androidx.constraintlayout.widget.ConstraintLayout.onLayout(ConstraintLayout.java:1855) at android.view.View.layout(View.java:23693) at android.view.ViewGroup.layout(ViewGroup.java:6413) at android.widget.FrameLayout.layoutChildren(FrameLayout.java:332) at android.widget.FrameLayout.onLayout(FrameLayout.java:270) at android.view.View.layout(View.java:23693) at android.view.ViewGroup.layout(ViewGroup.java:6413) at androidx.appcompat.widget.ActionBarOverlayLayout.onLayout(ActionBarOverlayLayout.java:536) at android.view.View.layout(View.java:23693) at android.view.ViewGroup.layout(ViewGroup.java:6413) at android.widget.FrameLayout.layoutChildren(FrameLayout.java:332) at android.widget.FrameLayout.onLayout(FrameLayout.java:270) at android.view.View.layout(View.java:23693) at android.view.ViewGroup.layout(ViewGroup.java:6413) at android.widget.LinearLayout.setChildFrame(LinearLayout.java:1891) at android.widget.LinearLayout.layoutVertical(LinearLayout.java:1729) at android.widget.LinearLayout.onLayout(LinearLayout.java:1638) at android.view.View.layout(View.java:23693) at android.view.ViewGroup.layout(ViewGroup.java:6413) at android.widget.FrameLayout.layoutChildren(FrameLayout.java:332) at android.widget.FrameLayout.onLayout(FrameLayout.java:270) at com.android.internal.policy.DecorView.onLayout(DecorView.java:799) at android.view.View.layout(View.java:23693) at android.view.ViewGroup.layout(ViewGroup.java:6413) at android.view.ViewRootImpl.performLayout(ViewRootImpl.java:3999) at android.view.ViewRootImpl.performTraversals(ViewRootImpl.java:3372) at android.view.ViewRootImpl.doTraversal(ViewRootImpl.java:2328) at android.view.ViewRootImpl$TraversalRunnable.run(ViewRootImpl.java:9087) at android.view.Choreographer$CallbackRecord.run(Choreographer.java:1231) at android.view.Choreographer$CallbackRecord.run(Choreographer.java:1239) at android.view.Choreographer.doCallbacks(Choreographer.java:899) at android.view.Choreographer.doFrame(Choreographer.java:832) at android.view.Choreographer$FrameDisplayEventReceiver.run(Choreographer.java:1214) at android.os.Handler.handleCallback(Handler.java:942) at android.os.Handler.dispatchMessage(Handler.java:99) at android.os.Looper.loopOnce(Looper.java:201) at android.os.Looper.loop(Looper.java:288) at android.app.ActivityThread.main(ActivityThread.java:7872) at java.lang.reflect.Method.invoke(Native Method) at com.android.internal.os.RuntimeInit$MethodAndArgsCaller.run(RuntimeInit.java:548) at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:936)

这是一个 Android 平台的运行时错误，具体错误信息为：在 ClubinfoAdpter.java 的第 44 行尝试调用一个空对象的方法 setText(CharSequence)，因此出现了 NullPointerException 异常。建议检查 ClubinfoAdpter.java 中的代码，确保 TextView 对象已经正确初始化并且不为空。如果问题仍然存在，可以提供更多相关的代码和上下文信息以便更好地排查问题。