传递整数片段片段 - sectionsPageAdapter，ViewPager

Question

我所试图做的事：

我有承载两个片段的活动 - CreateActivity.java承载Fragment1.java和Fragment2.java。

当在Fragment1中点击ListFragment中的项目时，我想切换到查看Fragment2并根据Fragment1中列表中单击的位置显示一些信息。

我试图通过列表中的“位置”的价值，像这样：在片段1 ListFragment项目

用户点击这个代码，然后将“位置”向CreateActivity.java值：

OnMemeSelectedListener mCallback; 

public interface OnListSelectedListener { 
    public void onArticleSelected(int position); 
} 

public void onAttach(Activity activity) { 
    super.onAttach(activity); 
    try { 
     mCallback = (OnListSelectedListener) activity; 
    } catch (ClassCastException e) { 
     throw new ClassCastException(activity.toString() 
       + " must implement OnHeadlineSelectedListener"); 
    } 
} 

@Override 
public void onListItemClick(ListView l, View v, int position, long id) { 
    super.onListItemClick(l, v, position, id); 
    mCallback.onArticleSelected(position); 
} 

在CreateActivity.java下面的方法被调用，以获得整数“位置”：

@Override 
public void onArticleSelected(int position) { 
    // Fragment2 newFragment = new Fragment2(); 
    Bundle args = new Bundle(); 
    args.putInt(Fragment2.ARG_POSITION, position); 
    Fragment2 fragobj = new Fragment2(); 
    fragobj.setArguments(args); 
    Log.w("myApp", "" + position); 
    //Switch to Fragment2 Tab 
    mViewPager.setCurrentItem(1); 
} 

截至这是完全的工作作为日志输出正确的位置列表。现在获得Fragment2.class我写了下面这行的整数：

int Position = getArguments().getInt(ARG_POSITION, position); 

但是我在开始CreateActivity.java得到NullPointError在我的日志：

08-31 17:45:04.102: E/AndroidRuntime(14779): FATAL EXCEPTION: main 
08-31 17:45:04.102: E/AndroidRuntime(14779): java.lang.NullPointerException 
08-31 17:45:04.102: E/AndroidRuntime(14779): at com.meme.hdmeme.Fragment2.onCreateView(Fragment2.java:59) 
08-31 17:45:04.102: E/AndroidRuntime(14779): at android.support.v4.app.Fragment.performCreateView(Fragment.java:1478) 
08-31 17:45:04.102: E/AndroidRuntime(14779): at android.support.v4.app.FragmentManagerImpl.moveToState(FragmentManager.java:927) 
08-31 17:45:04.102: E/AndroidRuntime(14779): at android.support.v4.app.FragmentManagerImpl.moveToState(FragmentManager.java:1104) 
08-31 17:45:04.102: E/AndroidRuntime(14779): at android.support.v4.app.BackStackRecord.run(BackStackRecord.java:682) 
08-31 17:45:04.102: E/AndroidRuntime(14779): at android.support.v4.app.FragmentManagerImpl.execPendingActions(FragmentManager.java:1460) 
08-31 17:45:04.102: E/AndroidRuntime(14779): at android.support.v4.app.FragmentManagerImpl.executePendingTransactions(FragmentManager.java:472) 
08-31 17:45:04.102: E/AndroidRuntime(14779): at android.support.v4.app.FragmentPagerAdapter.finishUpdate(FragmentPagerAdapter.java:141) 
08-31 17:45:04.102: E/AndroidRuntime(14779): at android.support.v4.view.ViewPager.populate(ViewPager.java:1068) 
08-31 17:45:04.102: E/AndroidRuntime(14779): at android.support.v4.view.ViewPager.populate(ViewPager.java:914) 
08-31 17:45:04.102: E/AndroidRuntime(14779): at android.support.v4.view.ViewPager.onMeasure(ViewPager.java:1436) 
08-31 17:45:04.102: E/AndroidRuntime(14779): at android.view.View.measure(View.java:15518) 
08-31 17:45:04.102: E/AndroidRuntime(14779): at android.view.ViewGroup.measureChildWithMargins(ViewGroup.java:4825) 
08-31 17:45:04.102: E/AndroidRuntime(14779): at android.widget.FrameLayout.onMeasure(FrameLayout.java:310) 
08-31 17:45:04.102: E/AndroidRuntime(14779): at android.view.View.measure(View.java:15518) 
08-31 17:45:04.102: E/AndroidRuntime(14779): at android.widget.LinearLayout.measureVertical(LinearLayout.java:847) 
08-31 17:45:04.102: E/AndroidRuntime(14779): at android.widget.LinearLayout.onMeasure(LinearLayout.java:588) 
08-31 17:45:04.102: E/AndroidRuntime(14779): at android.view.View.measure(View.java:15518) 
08-31 17:45:04.102: E/AndroidRuntime(14779): at android.view.ViewGroup.measureChildWithMargins(ViewGroup.java:4825) 
08-31 17:45:04.102: E/AndroidRuntime(14779): at android.widget.FrameLayout.onMeasure(FrameLayout.java:310) 
08-31 17:45:04.102: E/AndroidRuntime(14779): at com.android.internal.policy.impl.PhoneWindow$DecorView.onMeasure(PhoneWindow.java:2313) 
08-31 17:45:04.102: E/AndroidRuntime(14779): at android.view.View.measure(View.java:15518) 
08-31 17:45:04.102: E/AndroidRuntime(14779): at android.view.ViewRootImpl.performMeasure(ViewRootImpl.java:1874) 
08-31 17:45:04.102: E/AndroidRuntime(14779): at android.view.ViewRootImpl.measureHierarchy(ViewRootImpl.java:1089) 
08-31 17:45:04.102: E/AndroidRuntime(14779): at android.view.ViewRootImpl.performTraversals(ViewRootImpl.java:1265) 
08-31 17:45:04.102: E/AndroidRuntime(14779): at android.view.ViewRootImpl.doTraversal(ViewRootImpl.java:989) 
08-31 17:45:04.102: E/AndroidRuntime(14779): at android.view.ViewRootImpl$TraversalRunnable.run(ViewRootImpl.java:4351) 
08-31 17:45:04.102: E/AndroidRuntime(14779): at android.view.Choreographer$CallbackRecord.run(Choreographer.java:749) 
08-31 17:45:04.102: E/AndroidRuntime(14779): at android.view.Choreographer.doCallbacks(Choreographer.java:562) 
08-31 17:45:04.102: E/AndroidRuntime(14779): at android.view.Choreographer.doFrame(Choreographer.java:532) 
08-31 17:45:04.102: E/AndroidRuntime(14779): at android.view.Choreographer$FrameDisplayEventReceiver.run(Choreographer.java:735) 
08-31 17:45:04.102: E/AndroidRuntime(14779): at android.os.Handler.handleCallback(Handler.java:725) 
08-31 17:45:04.102: E/AndroidRuntime(14779): at android.os.Handler.dispatchMessage(Handler.java:92) 
08-31 17:45:04.102: E/AndroidRuntime(14779): at android.os.Looper.loop(Looper.java:137) 
08-31 17:45:04.102: E/AndroidRuntime(14779): at android.app.ActivityThread.main(ActivityThread.java:5195) 
08-31 17:45:04.102: E/AndroidRuntime(14779): at java.lang.reflect.Method.invokeNative(Native Method) 
08-31 17:45:04.102: E/AndroidRuntime(14779): at java.lang.reflect.Method.invoke(Method.java:511) 
08-31 17:45:04.102: E/AndroidRuntime(14779): at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:795) 
08-31 17:45:04.102: E/AndroidRuntime(14779): at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:562) 
08-31 17:45:04.102: E/AndroidRuntime(14779): at dalvik.system.NativeStart.main(Native Method) 

我一直停留在这几个小时和无法找到一个解决方法，在所有59行（导致NPE）是：

int Position = getArguments().getInt(ARG_POSITION, position); 

我必须创建之前就设置Fragment2的论点？我想在这个活动中创建这个数据之后传递给Fragment2，有什么想法吗？

感谢

Answer 1

看起来你在呼唤你onCreateView 。那时候还没有任何争论。

覆盖Fragment2中的setArguments，并将相关代码显示出您从第一个Fragment中获取的内容。

这有可能进入你的Fragment2：

@Override 
    public void setArguments(Bundle args) { 
     super.setArguments(args); 
     int Position = args.getInt(ARG_POSITION, position); 

     // now adjust what ever you want to display 
    }