Android 使用SwipeRefreshLayout刷新时按back键时屏幕上仍显示片段

我有一个包含两个片段的活动：A和B。目前A添加到活动中。单击按钮后：

ft.replace(containerId, B, tag);
ft.addToBackStack("A");
ft.commit();

B显示，A正常移除。 拉动刷新，并在加载进度时按back：

// this is implementation in OnBackPressed()
....
int backStackEntryCount = fm.getBackStackEntryCount();
if (backStackEntryCount > 0) {
    fm.popBackStackImmediate();
}
....

问题是屏幕上仍然显示片段B（空白）和重叠片段A，如果再次返回，应用程序将退出。关于B的一些信息：

• 我在B上实现了布局
• 以下是B源代码：

  public class B extends MyFragment {
  
  protected View view;
  protected ListView listView;
  protected ImageView progress;
  protected TextView notifText;
  protected LayoutInflater inflater;
  protected PTRBaseAdapter adapter;
  protected SwipeRefreshLayout mSwipeRefreshLayout;
  
  protected String emptyText;
  protected boolean fromRest;
  protected int loads = 0;
  protected float mPreviousX = 0;
  protected float mPreviousY = 0;
  
  protected void doRefresh(boolean fromRest) {
      if (!isAdded()) return;
      notifText.setVisibility(View.GONE);
      fetchFromDatabase();
      if (fromRest) {
          refresh();
      }
  }
  
  private void fetchFromDatabase() {
      /* fetch data from db here and got the "list" */
      adapter = new EventAdapter(list);
      listView.setAdapter(adapter);
      loads++;
      if (adapter.getCount() == 0) {
          notifText.setText(R.string.NoEvents);
          notifText.setVisibility(View.VISIBLE);
      } else {
          notifText.setVisibility(View.GONE);
      }
  }
  
  private void refresh() {
      if (!isAdded()) return;
      GenericManager.getInstance().fetchEvents(mContext, new OnFinished() {
          @Override
          public void onFinished(boolean result) {
              if (result) {
                  if (isAdded() && getActivity() != null) {
                      fetchFromDatabase();
                      adapter.notifyDataSetChanged();
                      listView.invalidate();
                      mSwipeRefreshLayout.setRefreshing(false);
                  }
              }
          }
      });
  }
  
  @Override
  public View onCreateView(LayoutInflater inflater, ViewGroup container, Bundle savedInstanceState) {
      view = inflater.inflate(R.layout.ptr_list, container, false);
      this.inflater = inflater;
      mSwipeRefreshLayout = (SwipeRefreshLayout) view.findViewById(R.id.swipeRefresh);
      mSwipeRefreshLayout.setColorSchemeResources(R.color.md_material_blue_600);
  
      listView = (ListView) view.findViewById(R.id.pull_refresh_list);
      listView.setOnItemClickListener(mOnItemClickListener);
      listView.setOnScrollListener(new AbsListView.OnScrollListener() {
          @Override
          public void onScrollStateChanged(AbsListView view, int scrollState) {
  
          }
  
          @Override
          public void onScroll(AbsListView view, int firstVisibleItem, int visibleItemCount, int totalItemCount) {
              boolean enable = false;
              if (listView != null && listView.getChildCount() > 0) {
                  boolean firstItemVisible = (listView.getFirstVisiblePosition() == 0);
                  boolean topOfFirstItemVisible = (listView.getChildAt(0).getTop() == 0);
                  enable = firstItemVisible && topOfFirstItemVisible;
              }
              mSwipeRefreshLayout.setEnabled(enable);
          }
      });
  
      mSwipeRefreshLayout.setOnRefreshListener(new SwipeRefreshLayout.OnRefreshListener() {
          @Override
          public void onRefresh() {
              refresh();
          }
      });
  
      progress = (ImageView) view.findViewById(R.id.progress);
      progress.setVisibility(View.GONE);
  
      notifText = (TextView) view.findViewById(R.id.notifText);
      notifText.setOnTouchListener(new View.OnTouchListener() {
          @Override
          public boolean onTouch(View v, MotionEvent event) {
  
              int action = event.getActionMasked();
              float x = event.getX();
              float y = event.getY();
  
              switch (action) {
                  case MotionEvent.ACTION_DOWN:
                      break;
                  case MotionEvent.ACTION_MOVE:
                      float dx = x - mPreviousX;
                      float dy = y - mPreviousY;
  
                      if (dy > 300) {
                          mSwipeRefreshLayout.post(new Runnable() {
                              @Override
                              public void run() {
                                  mSwipeRefreshLayout.setRefreshing(true);
                                  doRefresh(fromRest);
                              }
                          });
                      }
                      break;
                  case MotionEvent.ACTION_UP:
                      break;
              }
              mPreviousX = x;
              mPreviousY = y;
              return true;
          }
      });
  
      setTopbarTitle();
      return view;
  }
  
  @Override
  public void onActivityCreated(Bundle savedInstanceState) {
      super.onActivityCreated(savedInstanceState);
      doRefresh(true);
  }
  
  @Override
  public void setTopbarTitle() {
      topbar = (TopBar) getActivity().findViewById(R.id.topbar);
      topbarTitle = R.string.Events;
      ((MyActivity) getActivity()).setTabBarVisibility(false);
      topbar.setVisibility(View.VISIBLE);
      super.setTopbarTitle();
  }
  
  @Override
  public void onResume() {
      doRefresh(false);
      super.onResume();
  }
  
  /* The adapter for list but I think it does not affect anything */
  

在MyFragment中，我覆盖了OnDetach：

  @Override
  public void onDetach() {
    super.onDetach();
    try {
        Field childFragmentManager = Fragment.class.getDeclaredField("mChildFragmentManager");
        childFragmentManager.setAccessible(true);
        childFragmentManager.set(this, null);

    } catch (NoSuchFieldException e) {
        throw new RuntimeException(e);
    } catch (IllegalAccessException e) {
        throw new RuntimeException(e);
    }
}

片段B的布局：

<?xml version="1.0" encoding="utf-8"?>
<android.support.v4.widget.SwipeRefreshLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:tools="http://schemas.android.com/tools"
    android:id="@+id/swipeRefresh"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    tools:context=".MyActivity">

    <RelativeLayout
        style="@style/viewstyle">

        <com.myapp.viewcomp.TopBar
            android:id="@+id/topbar"
            android:layout_width="match_parent"
            android:layout_height="wrap_content"
            android:visibility="gone" />

        <ImageView
            android:id="@+id/progress"
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:layout_centerInParent="true"
            android:src="@drawable/progress" />

        <ListView
            android:id="@+id/pull_refresh_list"
            style="@style/ptr_style"
            android:background="@color/white"
            android:divider="@color/white"
            android:layout_width="match_parent"
            android:layout_height="match_parent"
            android:layout_below="@id/topbar" />

        <TextView
            android:id="@+id/notifText"
            android:layout_width="match_parent"
            android:layout_height="match_parent"
            android:layout_below="@id/progress"
            android:layout_centerInParent="true"
            android:gravity="center"
            android:paddingLeft="20dp"
            android:paddingRight="20dp"
            android:visibility="gone" />
    </RelativeLayout>

</android.support.v4.widget.SwipeRefreshLayout>

我不知道为什么碎片B进入了onDetach，但它仍然冻结在屏幕上，我可以在底部看到一点碎片。任何建议都是非常感谢的，我在这几天的时间里对这件事感到结巴：(

---

我认为问题出在B片段的实现中，但我无法解决，不确定问题是否来自SwipeRefreshLayout…

我自己解决了问题

mSwipeRefreshLayout.destroyDrawingCache();

---

既然您将替换事务添加到backstack中，那么让android处理backpress并从onbackpress中删除代码怎么样如果我让super.onbackpress（），应用程序将在单击“上一步”按钮后立即退出，并且OnBackPressed中的剪贴代码在许多情况下都会从我活动中的其他片段中删除，因此我无法删除它…请尝试onDestroy（）