android - fragment - removeGlobalOnLayoutListener IllegalStateException

Question

我正在尝试使用以下 ViewTreeObserver 获取 Fragment 中 ImageView 的高度和宽度:

import android.view.ViewTreeObserver;
import android.view.ViewTreeObserver.OnGlobalLayoutListener;

private ImageView imageViewPicture;

@Override
public View onCreateView(LayoutInflater inflater, ViewGroup container, Bundle savedInstanceState) {
    View view = inflater.inflate(R.layout.fragment_general_activity_add_recipe, container, false);
    setHasOptionsMenu(true);

    ...

    final ViewTreeObserver observer = imageViewPicture.getViewTreeObserver();
    observer.addOnGlobalLayoutListener (new OnGlobalLayoutListener () {
        @Override public void onGlobalLayout() {
            observer.removeGlobalOnLayoutListener(this);
        }
    });

    return view;
}

运行此代码会导致以下异常:

10-12 23:45:26.145: E/AndroidRuntime(12592): FATAL EXCEPTION: main
10-12 23:45:26.145: E/AndroidRuntime(12592): java.lang.IllegalStateException: This ViewTreeObserver is not alive, call getViewTreeObserver() again
10-12 23:45:26.145: E/AndroidRuntime(12592):     at android.view.ViewTreeObserver.checkIsAlive(ViewTreeObserver.java:509)
10-12 23:45:26.145: E/AndroidRuntime(12592):     at android.view.ViewTreeObserver.removeGlobalOnLayoutListener(ViewTreeObserver.java:356)
10-12 23:45:26.145: E/AndroidRuntime(12592):     at com.thimmey.rezepte.AddRecipeActivity_GeneralFragment$1.onGlobalLayout(AddActivity_GeneralFragment.java:83)
10-12 23:45:26.145: E/AndroidRuntime(12592):     at android.view.ViewTreeObserver.dispatchOnGlobalLayout(ViewTreeObserver.java:566)
10-12 23:45:26.145: E/AndroidRuntime(12592):     at android.view.ViewRootImpl.performTraversals(ViewRootImpl.java:1736)
10-12 23:45:26.145: E/AndroidRuntime(12592):     at android.view.ViewRootImpl.handleMessage(ViewRootImpl.java:2644)
10-12 23:45:26.145: E/AndroidRuntime(12592):     at android.os.Handler.dispatchMessage(Handler.java:99)
10-12 23:45:26.145: E/AndroidRuntime(12592):     at android.os.Looper.loop(Looper.java:137)
10-12 23:45:26.145: E/AndroidRuntime(12592):     at android.app.ActivityThread.main(ActivityThread.java:4517)
10-12 23:45:26.145: E/AndroidRuntime(12592):     at java.lang.reflect.Method.invokeNative(Native Method)
10-12 23:45:26.145: E/AndroidRuntime(12592):     at java.lang.reflect.Method.invoke(Method.java:511)
10-12 23:45:26.145: E/AndroidRuntime(12592):     at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:993)
10-12 23:45:26.145: E/AndroidRuntime(12592):     at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:760)
10-12 23:45:26.145: E/AndroidRuntime(12592):     at dalvik.system.NativeStart.main(Native Method)

文档说 removeGlobalOnLayoutListener 已被弃用，但如果我按照建议使用 removeOnGlobalLayoutListener，我会收到未定义的错误。

我做错了什么？

Answer 1

试试这个:

   ViewTreeObserver observer = imageViewPicture.getViewTreeObserver();
   observer.addOnGlobalLayoutListener (new OnGlobalLayoutListener () {
    @Override
     public void onGlobalLayout() {

       imageViewPicture.getViewTreeObserver().removeGlobalOnLayoutListener(this);
      }
    });