0
我试图让这个代码工作:如何正确使用视图和布局对象的混合使用instantiateItem?
@Override
public Object instantiateItem(ViewGroup collection, int position) {
View v = null;
if(0 == position) {
String data = "<html><body>Hi there</body><html>";
WebView wv = (WebView) findViewById(R.id.webView);
wv.loadData(data, "text/html", null);
v = wv;
}
else {
LayoutInflater vi = (LayoutInflater) cxt.getSystemService(Context.LAYOUT_INFLATER_SERVICE);
v = vi.inflate(R.layout.editor, null);
}
collection.addView(v,0);
return v;
}
我基本上模仿本文在这里建一个水平刷卡观点:http://android-developers.blogspot.com/2011/08/horizontal-view-swiping-with-viewpager.html
我得到一个崩溃时,我使用此代码。我通过尝试将布局插入到ViewGroup中来收集我没有正确执行的操作。有什么建议么?
03-20 14:49:55.037: ERROR/AndroidRuntime(25990): FATAL EXCEPTION: main
java.lang.NullPointerException
at com.EditorHyde.app.b.a(Unknown Source)
at android.support.v4.view.ViewPager.a(Unknown Source)
at android.support.v4.view.ViewPager.a(Unknown Source)
at android.support.v4.view.ViewPager.c(Unknown Source)
at android.support.v4.view.ViewPager.onMeasure(Unknown Source)
at android.view.View.measure(View.java:15518)
at android.view.ViewGroup.measureChildWithMargins(ViewGroup.java:4825)
at android.widget.LinearLayout.measureChildBeforeLayout(LinearLayout.java:1404)
at android.widget.LinearLayout.measureVertical(LinearLayout.java:695)
at android.widget.LinearLayout.onMeasure(LinearLayout.java:588)
at android.view.View.measure(View.java:15518)
at android.view.ViewGroup.measureChildWithMargins(ViewGroup.java:4825)
at android.widget.FrameLayout.onMeasure(FrameLayout.java:310)
at android.view.View.measure(View.java:15518)
at android.widget.LinearLayout.measureVertical(LinearLayout.java:847)
at android.widget.LinearLayout.onMeasure(LinearLayout.java:588)
at android.view.View.measure(View.java:15518)
at android.view.ViewGroup.measureChildWithMargins(ViewGroup.java:4825)
at android.widget.FrameLayout.onMeasure(FrameLayout.java:310)
at com.android.internal.policy.impl.PhoneWindow$DecorView.onMeasure(PhoneWindow.java:2176)
at android.view.View.measure(View.java:15518)
at android.view.ViewRootImpl.performMeasure(ViewRootImpl.java:1874)
at android.view.ViewRootImpl.measureHierarchy(ViewRootImpl.java:1089)
at android.view.ViewRootImpl.performTraversals(ViewRootImpl.java:1265)
at android.view.ViewRootImpl.doTraversal(ViewRootImpl.java:989)
at android.view.ViewRootImpl$TraversalRunnable.run(ViewRootImpl.java:4351)
at android.view.Choreographer$CallbackRecord.run(Choreographer.java:749)
at android.view.Choreographer.doCallbacks(Choreographer.java:562)
at android.view.Choreographer.doFrame(Choreographer.java:532)
at android.view.Choreographer$FrameDisplayEventReceiver.run(Choreographer.java:735)
at android.os.Handler.handleCallback(Handler.java:725)
at android.os.Handler.dispatchMessage(Handler.java:92)
at android.os.Looper.loop(Looper.java:137)
at android.app.ActivityThread.main(ActivityThread.java:5041)
at java.lang.reflect.Method.invokeNative(Native Method)
at java.lang.reflect.Method.invoke(Method.java:511)
at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:793)
at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:560)
at dalvik.system.NativeStart.main(Native Method)
我会尝试。但不知道为什么会导致空指针异常。谢谢 – xrd 2013-03-20 22:10:48
同样的问题。这是一个运行时问题。您的修复将会是编译时问题。 – xrd 2013-03-20 22:57:48
尝试更改if(0 ==位置)为if(位置== 0)。 idk但0 ==位置似乎很奇怪。 – 2014-07-13 22:28:10