SwipeRefreshLayout与EmptyView NullPointerException异常 [英] SwipeRefreshLayout with EmptyView nullPointerException
本文介绍了SwipeRefreshLayout与EmptyView NullPointerException异常的处理方法，对大家解决问题具有一定的参考价值，需要的朋友们下面随着小编来一起学习吧！
问题描述
每当我向下滑动即可刷新，我得到一个NullPointerException异常，但它不是在的我的code 的，而从SwipeRefreshLayout的startRefresh（）方法。
Whenever I swipe down to refresh, I get a NullPointerException but it's not in my code, rather in the startRefresh() method from SwipeRefreshLayout.
07-14 11:55:06.714: E/AndroidRuntime(20484): java.lang.NullPointerException
07-14 11:55:06.714: E/AndroidRuntime(20484): at android.support.v4.widget.SwipeRefreshLayout.startRefresh(SwipeRefreshLayout.java:441)
07-14 11:55:06.714: E/AndroidRuntime(20484): at android.support.v4.widget.SwipeRefreshLayout.onTouchEvent(SwipeRefreshLayout.java:399)
07-14 11:55:06.714: E/AndroidRuntime(20484): at android.view.View.dispatchTouchEvent(View.java:7253)
07-14 11:55:06.714: E/AndroidRuntime(20484): at android.view.ViewGroup.dispatchTransformedTouchEvent(ViewGroup.java:2168)
07-14 11:55:06.714: E/AndroidRuntime(20484): at android.view.ViewGroup.dispatchTouchEvent(ViewGroup.java:1903)
07-14 11:55:06.714: E/AndroidRuntime(20484): at android.view.ViewGroup.dispatchTransformedTouchEvent(ViewGroup.java:2174)
07-14 11:55:06.714: E/AndroidRuntime(20484): at android.view.ViewGroup.dispatchTouchEvent(ViewGroup.java:1917)
07-14 11:55:06.714: E/AndroidRuntime(20484): at android.view.ViewGroup.dispatchTransformedTouchEvent(ViewGroup.java:2174)
07-14 11:55:06.714: E/AndroidRuntime(20484): at android.view.ViewGroup.dispatchTouchEvent(ViewGroup.java:1917)
07-14 11:55:06.714: E/AndroidRuntime(20484): at android.view.ViewGroup.dispatchTransformedTouchEvent(ViewGroup.java:2174)
07-14 11:55:06.714: E/AndroidRuntime(20484): at android.view.ViewGroup.dispatchTouchEvent(ViewGroup.java:1917)
07-14 11:55:06.714: E/AndroidRuntime(20484): at android.view.ViewGroup.dispatchTransformedTouchEvent(ViewGroup.java:2174)
07-14 11:55:06.714: E/AndroidRuntime(20484): at android.view.ViewGroup.dispatchTouchEvent(ViewGroup.java:1917)
07-14 11:55:06.714: E/AndroidRuntime(20484): at com.android.internal.policy.impl.PhoneWindow$DecorView.superDispatchTouchEvent(PhoneWindow.java:2215)
07-14 11:55:06.714: E/AndroidRuntime(20484): at com.android.internal.policy.impl.PhoneWindow.superDispatchTouchEvent(PhoneWindow.java:1458)
07-14 11:55:06.714: E/AndroidRuntime(20484): at android.app.Activity.dispatchTouchEvent(Activity.java:2410)
07-14 11:55:06.714: E/AndroidRuntime(20484): at com.android.internal.policy.impl.PhoneWindow$DecorView.dispatchTouchEvent(PhoneWindow.java:2163)
07-14 11:55:06.714: E/AndroidRuntime(20484): at android.view.View.dispatchPointerEvent(View.java:7433)
07-14 11:55:06.714: E/AndroidRuntime(20484): at android.view.ViewRootImpl.deliverPointerEvent(ViewRootImpl.java:3220)
07-14 11:55:06.714: E/AndroidRuntime(20484): at android.view.ViewRootImpl.deliverInputEvent(ViewRootImpl.java:3165)
07-14 11:55:06.714: E/AndroidRuntime(20484): at android.view.ViewRootImpl.doProcessInputEvents(ViewRootImpl.java:4292)
07-14 11:55:06.714: E/AndroidRuntime(20484): at android.view.ViewRootImpl.enqueueInputEvent(ViewRootImpl.java:4271)
07-14 11:55:06.714: E/AndroidRuntime(20484): at android.view.ViewRootImpl$WindowInputEventReceiver.onInputEvent(ViewRootImpl.java:4363)
07-14 11:55:06.714: E/AndroidRuntime(20484): at android.view.InputEventReceiver.dispatchInputEvent(InputEventReceiver.java:179)
07-14 11:55:06.714: E/AndroidRuntime(20484): at android.view.InputEventReceiver.nativeConsumeBatchedInputEvents(Native Method)
07-14 11:55:06.714: E/AndroidRuntime(20484): at android.view.InputEventReceiver.consumeBatchedInputEvents(InputEventReceiver.java:171)
07-14 11:55:06.714: E/AndroidRuntime(20484): at android.view.ViewRootImpl.doConsumeBatchedInput(ViewRootImpl.java:4342)
07-14 11:55:06.714: E/AndroidRuntime(20484): at android.view.ViewRootImpl$ConsumeBatchedInputRunnable.run(ViewRootImpl.java:4382)
07-14 11:55:06.714: E/AndroidRuntime(20484): at android.view.Choreographer$CallbackRecord.run(Choreographer.java:749)
07-14 11:55:06.714: E/AndroidRuntime(20484): at android.view.Choreographer.doCallbacks(Choreographer.java:562)
07-14 11:55:06.714: E/AndroidRuntime(20484): at android.view.Choreographer.doFrame(Choreographer.java:530)
07-14 11:55:06.714: E/AndroidRuntime(20484): at android.view.Choreographer$FrameDisplayEventReceiver.run(Choreographer.java:735)
07-14 11:55:06.714: E/AndroidRuntime(20484): at android.os.Handler.handleCallback(Handler.java:725)
07-14 11:55:06.714: E/AndroidRuntime(20484): at android.os.Handler.dispatchMessage(Handler.java:92)
07-14 11:55:06.714: E/AndroidRuntime(20484): at android.os.Looper.loop(Looper.java:137)
07-14 11:55:06.714: E/AndroidRuntime(20484): at android.app.ActivityThread.main(ActivityThread.java:5227)
07-14 11:55:06.714: E/AndroidRuntime(20484): at java.lang.reflect.Method.invokeNative(Native Method)
07-14 11:55:06.714: E/AndroidRuntime(20484): at java.lang.reflect.Method.invoke(Method.java:511)
07-14 11:55:06.714: E/AndroidRuntime(20484): at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:795)
07-14 11:55:06.714: E/AndroidRuntime(20484): at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:562)
07-14 11:55:06.714: E/AndroidRuntime(20484): at dalvik.system.NativeStart.main(Native Method)
`
这是我的onCreate和我的主要活动onRefresh，MonitoredCoursesActivity：
This is my onCreate and onRefresh of my main Activity, MonitoredCoursesActivity:
public class MonitoredCoursesActivity extends ListActivity implements OnRefreshListener {
private SwipeRefreshLayout swipeLayout;
private ArrayList<Course> monitored;
private String lastUpdate;
private ListView myList;
private MyListAdapter myListAdapter;
final Context context = this;
// private int freqUpdate;
// private String updateTime;
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
if (loadState()==null) {
monitored = new ArrayList<Course>();
}
myList=(ListView)findViewById(android.R.id.list);
myListAdapter = new MyListAdapter(context, R.layout.row, monitored);
View empty = findViewById(android.R.id.empty);
myList.setEmptyView(empty);
myList.setAdapter(myListAdapter);
myList.setLongClickable(true);
registerForContextMenu(myList);
swipeLayout = (SwipeRefreshLayout) findViewById(R.id.swipe_container);
swipeLayout.setOnRefreshListener(this);
swipeLayout.setColorScheme(android.R.color.holo_blue_bright,
android.R.color.holo_green_light,
android.R.color.holo_orange_light,
android.R.color.holo_red_light);
swipeLayout.setHapticFeedbackEnabled(true);
@Override
public void onRefresh() {
new Handler().postDelayed(new Runnable() {
@Override public void run() {
//Refresh all courses in the list
updateCoursesInfo();
swipeLayout.setRefreshing(false);
}
}, 10000);
}
我activity_main.xml中：
My activity_main.xml:
<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:tools="http://schemas.android.com/tools"
android:layout_width="match_parent"
android:layout_height="match_parent" >
<android.support.v4.widget.SwipeRefreshLayout
xmlns:android="http://schemas.android.com/apk/res/android"
android:id="@+id/swipe_container"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:orientation="vertical"
android:text="@string/courses" >
<ListView
android:id="@android:id/list"
android:layout_width="fill_parent"
android:layout_height="0dip"
android:layout_weight="2"
android:cacheColorHint="#000000"
android:divider="#D5DDDE"
android:dividerHeight="1dp"
android:drawSelectorOnTop="false"
android:focusableInTouchMode="false"
android:footerDividersEnabled="false"
android:headerDividersEnabled="true"
android:listSelector="@android:color/transparent" />
</android.support.v4.widget.SwipeRefreshLayout>
<android.support.v4.widget.SwipeRefreshLayout
android:id="@+id/swipeRefreshLayout_emptyView"
android:layout_width="match_parent"
android:layout_height="match_parent" >
<ScrollView
android:layout_width="match_parent"
android:layout_height="match_parent"
android:scrollbarStyle="outsideOverlay" >
<TextView
android:id="@android:id/empty"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_gravity="center_vertical|center_horizontal"
android:alpha="0.18"
android:clickable="false"
android:gravity="center|center_vertical|center_horizontal"
android:longClickable="false"
android:text="@string/empty_list"
android:textAppearance="?android:attr/textAppearanceLarge"
android:textColor="@android:color/widget_edittext_dark"
android:textSize="35sp"
android:textStyle="bold"
android:typeface="normal" />
</ScrollView>
</android.support.v4.widget.SwipeRefreshLayout>
我row.xml为ListView的项目：
My row.xml for ListView items:
`
`
<GridLayout
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:columnCount="2" >
<TextView
android:id="@+id/txtCourseName"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_gravity="left"
android:layout_marginBottom="2dp"
android:paddingRight="5dp"
android:text="@string/section"
android:textSize="25sp" />
<TextView
android:id="@+id/txtSection"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_column="1"
android:layout_gravity="center"
android:layout_row="0"
android:text="@string/section"
android:textAppearance="?android:attr/textAppearanceMedium" />
</GridLayout>
<TextView
android:id="@+id/txtRemaining"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_marginRight="68dp"
android:text="@string/remaining"
android:textAppearance="?android:attr/textAppearanceMedium" />
<TextView
android:id="@+id/txtCRN"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:text="@string/crn"
android:textAppearance="?android:attr/textAppearanceMedium" />
<TextView
android:id="@+id/txtFecha"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_gravity="center_horizontal|top"
android:textAppearance="?android:attr/textAppearanceSmall" />
</LinearLayout>`
我已经搜查和<一个href=\"http://stackoverflow.com/questions/24298214/exception-dispatching-input-event-and-null-pointer-exception-on-swiperefreshlayo\">this是唯一类似的问题，但解决方案并不适用于我的情况（至少我是这么认为的）。任何线索？先谢谢了。
I've searched and this is the only similar question, but the solution doesn't apply to my case (or at least I think so). Any clues? Thanks in advance.
推荐答案
您需要有
context = this;
在的onCreate
在
myListAdapter = new MyListAdapter(context, R.layout.row, monitored);// here you are using context
上下文可一次活动是创建
441线是
mListener.onRefresh();
查看源
public void setOnRefreshListener(OnRefreshListener listener) {
mListener = listener;
}
因此，有你实施 OnRefreshListener 在适当的活动？
由于在聊天中讨论
删除第二 SwipeRefreshLayout
要设置一个空视图列表视图来阅读下面的，而不是具有其他swiperefreshlayout
To set a empty view to listview read the below instead of having the other swiperefreshlayout
http://cyrilmottier.com/2011 / 06/20 /列表视图-TIPS-技巧-1-手柄空虚/
这篇关于SwipeRefreshLayout与EmptyView NullPointerException异常的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持IT屋！
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