android - SwipeRefreshLayout 下拉异常分派输入事件和空指针异常

Question

我有一个滑动来刷新布局（android.support.v4 修订版 19.1 的一部分），当我在布局上向下滑动时，我可以到达顶部已满的位置，但进一步向下滑动将导致应用程序崩溃，并且 logcat 指向我的代码中没有特定的行。由于 SwipeRefreshLayout 才几个月大，因此互联网上没有很多信息可以帮助我找出问题所在。在我无法将支持 v4 修订版 19.1 添加到我的构建路径之前，但我很确定我已经解决了这个问题。这是 logcat，以及布局文件和我的 SwipeRefreshLayout 的代码。以及应用程序崩溃时的屏幕截图。

06-18 23:09:31.527: E/InputEventReceiver(25459): Exception dispatching input event.
06-18 23:09:31.547: E/AndroidRuntime(25459): FATAL EXCEPTION: main
06-18 23:09:31.547: E/AndroidRuntime(25459): Process: com.bernard.beaconportal, PID: 25459
06-18 23:09:31.547: E/AndroidRuntime(25459): java.lang.NullPointerException
06-18 23:09:31.547: E/AndroidRuntime(25459):    at android.support.v4.widget.SwipeRefreshLayout.startRefresh(SwipeRefreshLayout.java:441)
06-18 23:09:31.547: E/AndroidRuntime(25459):    at android.support.v4.widget.SwipeRefreshLayout.onTouchEvent(SwipeRefreshLayout.java:399)
06-18 23:09:31.547: E/AndroidRuntime(25459):    at android.view.View.dispatchTouchEvent(View.java:7706)
06-18 23:09:31.547: E/AndroidRuntime(25459):    at android.view.ViewGroup.dispatchTransformedTouchEvent(ViewGroup.java:2210)
06-18 23:09:31.547: E/AndroidRuntime(25459):    at android.view.ViewGroup.dispatchTouchEvent(ViewGroup.java:1945)
06-18 23:09:31.547: E/AndroidRuntime(25459):    at android.view.ViewGroup.dispatchTransformedTouchEvent(ViewGroup.java:2216)
06-18 23:09:31.547: E/AndroidRuntime(25459):    at android.view.ViewGroup.dispatchTouchEvent(ViewGroup.java:1959)
06-18 23:09:31.547: E/AndroidRuntime(25459):    at android.view.ViewGroup.dispatchTransformedTouchEvent(ViewGroup.java:2216)
06-18 23:09:31.547: E/AndroidRuntime(25459):    at android.view.ViewGroup.dispatchTouchEvent(ViewGroup.java:1959)
06-18 23:09:31.547: E/AndroidRuntime(25459):    at android.view.ViewGroup.dispatchTransformedTouchEvent(ViewGroup.java:2216)
06-18 23:09:31.547: E/AndroidRuntime(25459):    at android.view.ViewGroup.dispatchTouchEvent(ViewGroup.java:1959)
06-18 23:09:31.547: E/AndroidRuntime(25459):    at android.view.ViewGroup.dispatchTransformedTouchEvent(ViewGroup.java:2216)
06-18 23:09:31.547: E/AndroidRuntime(25459):    at android.view.ViewGroup.dispatchTouchEvent(ViewGroup.java:1959)
06-18 23:09:31.547: E/AndroidRuntime(25459):    at android.view.ViewGroup.dispatchTransformedTouchEvent(ViewGroup.java:2216)
06-18 23:09:31.547: E/AndroidRuntime(25459):    at android.view.ViewGroup.dispatchTouchEvent(ViewGroup.java:1959)
06-18 23:09:31.547: E/AndroidRuntime(25459):    at android.view.ViewGroup.dispatchTransformedTouchEvent(ViewGroup.java:2216)
06-18 23:09:31.547: E/AndroidRuntime(25459):    at android.view.ViewGroup.dispatchTouchEvent(ViewGroup.java:1959)
06-18 23:09:31.547: E/AndroidRuntime(25459):    at android.view.ViewGroup.dispatchTransformedTouchEvent(ViewGroup.java:2216)
06-18 23:09:31.547: E/AndroidRuntime(25459):    at android.view.ViewGroup.dispatchTouchEvent(ViewGroup.java:1959)
06-18 23:09:31.547: E/AndroidRuntime(25459):    at android.view.ViewGroup.dispatchTransformedTouchEvent(ViewGroup.java:2216)
06-18 23:09:31.547: E/AndroidRuntime(25459):    at android.view.ViewGroup.dispatchTouchEvent(ViewGroup.java:1959)
06-18 23:09:31.547: E/AndroidRuntime(25459):    at android.view.ViewGroup.dispatchTransformedTouchEvent(ViewGroup.java:2216)
06-18 23:09:31.547: E/AndroidRuntime(25459):    at android.view.ViewGroup.dispatchTouchEvent(ViewGroup.java:1959)
06-18 23:09:31.547: E/AndroidRuntime(25459):    at com.android.internal.policy.impl.PhoneWindow$DecorView.superDispatchTouchEvent(PhoneWindow.java:2339)
06-18 23:09:31.547: E/AndroidRuntime(25459):    at com.android.internal.policy.impl.PhoneWindow.superDispatchTouchEvent(PhoneWindow.java:1569)
06-18 23:09:31.547: E/AndroidRuntime(25459):    at android.app.Activity.dispatchTouchEvent(Activity.java:2492)
06-18 23:09:31.547: E/AndroidRuntime(25459):    at com.android.internal.policy.impl.PhoneWindow$DecorView.dispatchTouchEvent(PhoneWindow.java:2286)
06-18 23:09:31.547: E/AndroidRuntime(25459):    at android.view.View.dispatchPointerEvent(View.java:7886)
06-18 23:09:31.547: E/AndroidRuntime(25459):    at android.view.ViewRootImpl$ViewPostImeInputStage.processPointerEvent(ViewRootImpl.java:3947)
06-18 23:09:31.547: E/AndroidRuntime(25459):    at android.view.ViewRootImpl$ViewPostImeInputStage.onProcess(ViewRootImpl.java:3826)
06-18 23:09:31.547: E/AndroidRuntime(25459):    at android.view.ViewRootImpl$InputStage.deliver(ViewRootImpl.java:3392)
06-18 23:09:31.547: E/AndroidRuntime(25459):    at android.view.ViewRootImpl$InputStage.onDeliverToNext(ViewRootImpl.java:3442)
06-18 23:09:31.547: E/AndroidRuntime(25459):    at android.view.ViewRootImpl$InputStage.forward(ViewRootImpl.java:3411)
06-18 23:09:31.547: E/AndroidRuntime(25459):    at android.view.ViewRootImpl$AsyncInputStage.forward(ViewRootImpl.java:3518)
06-18 23:09:31.547: E/AndroidRuntime(25459):    at android.view.ViewRootImpl$InputStage.apply(ViewRootImpl.java:3419)
06-18 23:09:31.547: E/AndroidRuntime(25459):    at android.view.ViewRootImpl$AsyncInputStage.apply(ViewRootImpl.java:3575)
06-18 23:09:31.547: E/AndroidRuntime(25459):    at android.view.ViewRootImpl$InputStage.deliver(ViewRootImpl.java:3392)
06-18 23:09:31.547: E/AndroidRuntime(25459):    at android.view.ViewRootImpl$InputStage.onDeliverToNext(ViewRootImpl.java:3442)
06-18 23:09:31.547: E/AndroidRuntime(25459):    at android.view.ViewRootImpl$InputStage.forward(ViewRootImpl.java:3411)
06-18 23:09:31.547: E/AndroidRuntime(25459):    at android.view.ViewRootImpl$InputStage.apply(ViewRootImpl.java:3419)
06-18 23:09:31.547: E/AndroidRuntime(25459):    at android.view.ViewRootImpl$InputStage.deliver(ViewRootImpl.java:3392)
06-18 23:09:31.547: E/AndroidRuntime(25459):    at android.view.ViewRootImpl.deliverInputEvent(ViewRootImpl.java:5532)
06-18 23:09:31.547: E/AndroidRuntime(25459):    at android.view.ViewRootImpl.doProcessInputEvents(ViewRootImpl.java:5512)
06-18 23:09:31.547: E/AndroidRuntime(25459):    at android.view.ViewRootImpl.enqueueInputEvent(ViewRootImpl.java:5483)
06-18 23:09:31.547: E/AndroidRuntime(25459):    at android.view.ViewRootImpl$WindowInputEventReceiver.onInputEvent(ViewRootImpl.java:5612)
06-18 23:09:31.547: E/AndroidRuntime(25459):    at android.view.InputEventReceiver.dispatchInputEvent(InputEventReceiver.java:185)
06-18 23:09:31.547: E/AndroidRuntime(25459):    at android.view.InputEventReceiver.nativeConsumeBatchedInputEvents(Native Method)
06-18 23:09:31.547: E/AndroidRuntime(25459):    at android.view.InputEventReceiver.consumeBatchedInputEvents(InputEventReceiver.java:176)
06-18 23:09:31.547: E/AndroidRuntime(25459):    at android.view.ViewRootImpl.doConsumeBatchedInput(ViewRootImpl.java:5585)
06-18 23:09:31.547: E/AndroidRuntime(25459):    at android.view.ViewRootImpl$ConsumeBatchedInputRunnable.run(ViewRootImpl.java:5631)
06-18 23:09:31.547: E/AndroidRuntime(25459):    at android.view.Choreographer$CallbackRecord.run(Choreographer.java:761)
06-18 23:09:31.547: E/AndroidRuntime(25459):    at android.view.Choreographer.doCa

这是布局

<android.support.v4.widget.SwipeRefreshLayout 
    xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="wrap_content"
    android:background="#ffffff"
    android:id="@+id/swipe" >

    <ListView
        android:id="@+id/listView1"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_alignParentBottom="true"
        android:layout_alignParentLeft="true"
        android:layout_alignParentRight="true"
        android:layout_alignParentTop="true"
         android:background="#ffffff">

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

这是处理 SwipeRefreshLayout 的代码

SwipeRefreshLayout swipeLayout; 


    public static final String KEY_HOMEWORK="homework";
    public static final String KEY_DESC="desc";

    public View onCreateView(LayoutInflater inflater, ViewGroup container, Bundle savedInstanceState){


         View swipe = inflater.inflate(R.layout.activity_main, container, false); 

         swipeLayout = (SwipeRefreshLayout) swipe.findViewById(R.id.swipe);

         swipeLayout.setEnabled(false);

    ListView lView = (ListView) swipe.findViewById(R.id.listView1);

    lView.setOnScrollListener(new AbsListView.OnScrollListener() {
        @Override
        public void onScrollStateChanged(AbsListView absListView, int i) {

        }

        @Override
        public void onScroll(AbsListView absListView, int firstVisibleItem, int visibleItemCount, int totalItemCount) {
                if (firstVisibleItem == 0)
                    swipeLayout.setEnabled(true);
                else
                    swipeLayout.setEnabled(false);
        }
    });


    return swipe;

    }

这是它崩溃的屏幕截图，你可以看到它一直向下滑动，通常它会在此时触发一些东西。但随后它崩溃了。

score 4 · Accepted Answer

Your OnRefreshListener is null, either you haven't set one or at some point of your code you are setting it to null.

In the source of SwipeRefreshLayout, particularly in this snippet

 private void startRefresh() {
        removeCallbacks(mCancel);
        mReturnToStartPosition.run();
        setRefreshing(true);
        mListener.onRefresh();
    }

on line 441, the mListener.onRefresh(); raises NullPointerException.

score 0 · Accepted Answer

我想到了。由于此片段包含在视图分页器中，因此 SwipeRefreshLayout 会延续到视图分页器中的其他片段，但除非您向其中添加代码，否则其他片段会崩溃。对我来说真是愚蠢的错误。

android - SwipeRefreshLayout 下拉异常分派输入事件和空指针异常

2 回答 2

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