在 ViewPager 中使用 SwipeRefreshLayout 和 WebView答案

【问题标题】：Working with SwipeRefreshLayout and WebView inside ViewPager在 ViewPager 中使用 SwipeRefreshLayout 和 WebView
【发布时间】：2014-05-25 19:00:12
【问题描述】：

我在我的应用程序中使用SwipeRefreshLayout 和WebView 没有问题。

ViewPager 代码内：

@Override
public Object instantiateItem(View collection, int position) {

    currentArticle = newsList.get(position);

    View webViewContainer =  getActivity().getLayoutInflater().inflate(R.layout.view_pager_item, null);

    WebView webview = (WebView) webViewContainer.findViewById(R.id.webview);
    SetSettingForWebView(webview);
    webview.loadUrl(currentArticle.getArticleURL());
    SwipeRefreshLayout swipe = (SwipeRefreshLayout) webViewContainer.findViewById(R.id.swipe_container);
    setSettingForSwipeLayout(swipe);
    ((ViewPager) collection).addView(webViewContainer, 0);

    return webViewContainer;
}

无论我是否定义SwipeRefreshLayout，都会发生错误。

这是错误。如您所见，它与我的代码无关，但我不知道如何解决这个问题

日志：

05-25 21:55:59.804: E/AndroidRuntime(4665): FATAL EXCEPTION: main
05-25 21:55:59.804: E/AndroidRuntime(4665): Process: com.dimrix.test, PID: 4665
05-25 21:55:59.804: E/AndroidRuntime(4665): java.lang.NullPointerException
05-25 21:55:59.804: E/AndroidRuntime(4665):     at android.support.v4.widget.SwipeRefreshLayout.startRefresh(SwipeRefreshLayout.java:441)
05-25 21:55:59.804: E/AndroidRuntime(4665):     at android.support.v4.widget.SwipeRefreshLayout.onTouchEvent(SwipeRefreshLayout.java:399)
05-25 21:55:59.804: E/AndroidRuntime(4665):     at android.view.View.dispatchTouchEvent(View.java:7811)
05-25 21:55:59.804: E/AndroidRuntime(4665):     at android.view.ViewGroup.dispatchTransformedTouchEvent(ViewGroup.java:2210)
05-25 21:55:59.804: E/AndroidRuntime(4665):     at android.view.ViewGroup.dispatchTouchEvent(ViewGroup.java:1945)
05-25 21:55:59.804: E/AndroidRuntime(4665):     at android.view.ViewGroup.dispatchTransformedTouchEvent(ViewGroup.java:2216)
05-25 21:55:59.804: E/AndroidRuntime(4665):     at android.view.ViewGroup.dispatchTouchEvent(ViewGroup.java:1959)
05-25 21:55:59.804: E/AndroidRuntime(4665):     at android.view.ViewGroup.dispatchTransformedTouchEvent(ViewGroup.java:2216)
05-25 21:55:59.804: E/AndroidRuntime(4665):     at android.view.ViewGroup.dispatchTouchEvent(ViewGroup.java:1959)
05-25 21:55:59.804: E/AndroidRuntime(4665):     at android.view.ViewGroup.dispatchTransformedTouchEvent(ViewGroup.java:2216)
05-25 21:55:59.804: E/AndroidRuntime(4665):     at android.view.ViewGroup.dispatchTouchEvent(ViewGroup.java:1959)
05-25 21:55:59.804: E/AndroidRuntime(4665):     at android.view.ViewGroup.dispatchTransformedTouchEvent(ViewGroup.java:2216)
05-25 21:55:59.804: E/AndroidRuntime(4665):     at android.view.ViewGroup.dispatchTouchEvent(ViewGroup.java:1959)
05-25 21:55:59.804: E/AndroidRuntime(4665):     at android.view.ViewGroup.dispatchTransformedTouchEvent(ViewGroup.java:2216)
05-25 21:55:59.804: E/AndroidRuntime(4665):     at android.view.ViewGroup.dispatchTouchEvent(ViewGroup.java:1959)
05-25 21:55:59.804: E/AndroidRuntime(4665):     at android.view.ViewGroup.dispatchTransformedTouchEvent(ViewGroup.java:2216)
05-25 21:55:59.804: E/AndroidRuntime(4665):     at android.view.ViewGroup.dispatchTouchEvent(ViewGroup.java:1959)
05-25 21:55:59.804: E/AndroidRuntime(4665):     at android.view.ViewGroup.dispatchTransformedTouchEvent(ViewGroup.java:2216)
05-25 21:55:59.804: E/AndroidRuntime(4665):     at android.view.ViewGroup.dispatchTouchEvent(ViewGroup.java:1959)
05-25 21:55:59.804: E/AndroidRuntime(4665):     at android.view.ViewGroup.dispatchTransformedTouchEvent(ViewGroup.java:2216)
05-25 21:55:59.804: E/AndroidRuntime(4665):     at android.view.ViewGroup.dispatchTouchEvent(ViewGroup.java:1959)
05-25 21:55:59.804: E/AndroidRuntime(4665):     at android.view.ViewGroup.dispatchTransformedTouchEvent(ViewGroup.java:2216)
05-25 21:55:59.804: E/AndroidRuntime(4665):     at android.view.ViewGroup.dispatchTouchEvent(ViewGroup.java:1959)
05-25 21:55:59.804: E/AndroidRuntime(4665):     at android.view.ViewGroup.dispatchTransformedTouchEvent(ViewGroup.java:2216)
05-25 21:55:59.804: E/AndroidRuntime(4665):     at android.view.ViewGroup.dispatchTouchEvent(ViewGroup.java:1959)
05-25 21:55:59.804: E/AndroidRuntime(4665):     at android.view.ViewGroup.dispatchTransformedTouchEvent(ViewGroup.java:2216)
05-25 21:55:59.804: E/AndroidRuntime(4665):     at android.view.ViewGroup.dispatchTouchEvent(ViewGroup.java:1959)
05-25 21:55:59.804: E/AndroidRuntime(4665):     at android.view.ViewGroup.dispatchTransformedTouchEvent(ViewGroup.java:2216)
05-25 21:55:59.804: E/AndroidRuntime(4665):     at android.view.ViewGroup.dispatchTouchEvent(ViewGroup.java:1959)
05-25 21:55:59.804: E/AndroidRuntime(4665):     at android.view.ViewGroup.dispatchTransformedTouchEvent(ViewGroup.java:2216)
05-25 21:55:59.804: E/AndroidRuntime(4665):     at android.view.ViewGroup.dispatchTouchEvent(ViewGroup.java:1959)
05-25 21:55:59.804: E/AndroidRuntime(4665):     at com.android.internal.policy.impl.PhoneWindow$DecorView.superDispatchTouchEvent(PhoneWindow.java:2169)
05-25 21:55:59.804: E/AndroidRuntime(4665):     at com.android.internal.policy.impl.PhoneWindow.superDispatchTouchEvent(PhoneWindow.java:1613)
05-25 21:55:59.804: E/AndroidRuntime(4665):     at android.app.Activity.dispatchTouchEvent(Activity.java:2539)
05-25 21:55:59.804: E/AndroidRuntime(4665):     at android.support.v7.app.ActionBarActivityDelegateICS$WindowCallbackWrapper.dispatchTouchEvent(ActionBarActivityDelegateICS.java:268)
05-25 21:55:59.804: E/AndroidRuntime(4665):     at com.android.internal.policy.impl.PhoneWindow$DecorView.dispatchTouchEvent(PhoneWindow.java:2117)
05-25 21:55:59.804: E/AndroidRuntime(4665):     at android.view.View.dispatchPointerEvent(View.java:8005)
05-25 21:55:59.804: E/AndroidRuntime(4665):     at android.view.ViewRootImpl$ViewPostImeInputStage.processPointerEvent(ViewRootImpl.java:4300)
05-25 21:55:59.804: E/AndroidRuntime(4665):     at android.view.ViewRootImpl$ViewPostImeInputStage.onProcess(ViewRootImpl.java:4179)
05-25 21:55:59.804: E/AndroidRuntime(4665):     at android.view.ViewRootImpl$InputStage.deliver(ViewRootImpl.java:3714)
05-25 21:55:59.804: E/AndroidRuntime(4665):     at android.view.ViewRootImpl$InputStage.onDeliverToNext(ViewRootImpl.java:3764)
05-25 21:55:59.804: E/AndroidRuntime(4665):     at android.view.ViewRootImpl$InputStage.forward(ViewRootImpl.java:3733)
05-25 21:55:59.804: E/AndroidRuntime(4665):     at android.view.ViewRootImpl$AsyncInputStage.forward(ViewRootImpl.java:3844)
05-25 21:55:59.804: E/AndroidRuntime(4665):     at android.view.ViewRootImpl$InputStage.apply(ViewRootImpl.java:3741)
05-25 21:55:59.804: E/AndroidRuntime(4665):     at android.view.ViewRootImpl$AsyncInputStage.apply(ViewRootImpl.java:3901)
05-25 21:55:59.804: E/AndroidRuntime(4665):     at android.view.ViewRootImpl$InputStage.deliver(ViewRootImpl.java:3714)
05-25 21:55:59.804: E/AndroidRuntime(4665):     at android.view.ViewRootImpl$InputStage.onDeliverToNext(ViewRootImpl.java:3764)
05-25 21:55:59.804: E/AndroidRuntime(4665):     at android.view.ViewRootImpl$InputStage.forward(ViewRootImpl.java:3733)
05-25 21:55:59.804: E/AndroidRuntime(4665):     at android.view.ViewRootImpl$InputStage.apply(ViewRootImpl.java:3741)
05-25 21:55:59.804: E/AndroidRuntime(4665):     at android.view.ViewRootImpl$InputStage.deliver(ViewRootImpl.java:3714)
05-25 21:55:59.804: E/AndroidRuntime(4665):     at android.view.ViewRootImpl.deliverInputEvent(ViewRootImpl.java:5973)
05-25 21:55:59.804: E/AndroidRuntime(4665):     at android.view.ViewRootImpl.doProcessInputEvents(ViewRootImpl.ja

【问题讨论】：

标签： android android-viewpager android-support-library swiperefreshlayout

【解决方案1】：

SwipeRefreshLayout.java 的第 441 行是

    mListener.onRefresh();

你provide an OnRefreshListener 了吗？

【讨论】：

我做到了。即使我没有，我也不会崩溃。

【解决方案2】：

转到项目->Properties->Java Buildpath 并添加支持 library V4 并从 order 和 Export 检查库 选项卡，确保勾选标记。

【讨论】：

正如我所写，滑动在我的应用程序中的其他片段上运行良好

【解决方案3】：

这可能是因为您在 ViewPager 中有 SwipeRefreshLayout，即在 view_pager_item.xml 中。所以当SwipeRefreshLayout查找其上下文时，它会找到包含ViewPager的Activity或Fragment。

尝试将SwipeRefreshLayout 移动到包含 ViewPager 的 Activity 或 Fragment 中，看看效果如何。

【讨论】：

【解决方案4】：

您是否已为 SwipeRefreshLayout 视图设置了监听器？

例如，如果你的 Fragment/Activity 实现了SwipeRefreshLayout.OnRefreshListener，则需要将 SwipeRefreshLayout 实例设置为：

SwipeRefreshLayout layout = (SwipeRefreshLayout)view.findViewById(R.id.swipe);
layout.setOnRefreshListener(this);

这应该可以修复崩溃:)

【讨论】：