关于 java:Run time error while inflating SliderImages using Viewpager

Run time error while inflating SliderImages using Viewpager

这是我的股票片段 //

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

View view = inflater.inflate(R.layout.fragment_stock, container, false);
slideDotspanel = (LinearLayout) view.findViewById(R.id.SliderDots);

gridview = (GridView) view.findViewById(R.id.custom_grid);
gridview.setAdapter(new CustomAdapter(this, osNameList, osImages));

viewPager = (ViewPager) view.findViewById(R.id.viewpager);
adapter = new ViewPagerAdapter(this.getActivity());
viewPager.setAdapter(adapter);
return view;

这是我的 stockfragment.xml //

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<android.support.v4.view.ViewPager
android:layout_width="wrap_content"
android:id="@+id/viewPager"
android:layout_height="200dp"
android:layout_marginBottom="8dp" />
<LinearLayout
android:id="@+id/SliderDots"
android:layout_below="@+id/viewPager"
android:orientation="horizontal"
android:gravity="center_horizontal|center_vertical"
android:layout_width="match_parent"
android:layout_height="wrap_content">

</LinearLayout>

这是我的 ViewPagerAdapter 类 //

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class ViewPagerAdapter extends PagerAdapter {

private int[] image_resource = {R.drawable.arrow, R.drawable.bin, R.drawable.gallery, R.drawable.got};
private Context ctx;
private LayoutInflater layoutInflater;

public ViewPagerAdapter(Context ctx) {
this.ctx = ctx;
}

@Override
public int getCount() {
return image_resource.length;
}

@Override
public boolean isViewFromObject(View view, Object object) {
return (view == (ImageView)object);
}

@Override
public Object instantiateItem(ViewGroup container, int position) {
layoutInflater = (LayoutInflater) ctx.getSystemService(Context.LAYOUT_INFLATER_SERVICE);
View item_view = layoutInflater.inflate(R.layout.custom_layout, container, false);
ImageView imageview = (ImageView) item_view.findViewById(R.id.imageView);
imageview.setImageResource(image_resource[position]);

container.addView(item_view);
//((ViewPager) container).addView(item_view, 0);
return item_view;
}

@Override
public void destroyItem(ViewGroup container, int position, Object object) {
container.removeView((LinearLayout)object);
}

这是 ViewPagerAdapter.xml //

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android:orientation="vertical"
android:layout_width="match_parent"
android:layout_height="match_parent">
<android.support.v7.widget.AppCompatImageView
android:layout_width="match_parent"
android:layout_height="match_parent"
android:src="@mipmap/ic_launcher"
android:id="@+id/imageView"
/>

我的日志猫错误是

java.lang.NullPointerException: Attempt to invoke virtual method 'void
android.support.v4.view.ViewPager.setAdapter(android.support.v4.view.PagerAdapter)'
on a null object reference
at com.example.admin.navigationandtabbed.StockFragment.onCreateView(StockFragment.java:79)
at android.support.v4.app.Fragment.performCreateView(Fragment.java:2080)
at android.support.v4.app.FragmentManagerImpl.moveToState(FragmentManager.java:1108)
at android.support.v4.app.FragmentManagerImpl.moveToState(FragmentManager.java:1290)
at android.support.v4.app.BackStackRecord.run(BackStackRecord.java:801)

解释---

在抛出的 StockFragment 片段中此代码存在运行时错误
空指针异常的异常。
当我从 Activity 执行此操作时，相同的部分正在运行，但是当我在 Fragment 执行此操作时。它正在抛出错误。

请帮助
提前谢谢你。

viewPager 不同于 viewpager

在你的 StockFragment.java

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viewPager = (ViewPager) view.findViewById(R.id.viewpager);

改成

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viewPager = (ViewPager) view.findViewById(R.id.viewpager);