带有视页的对话框中出错

Question

我正试图从回收器视图图像点击打开一个对话框...该对话框包含一个视图页来创建一个滑动视图库..

holder.image.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View v) {

                final Dialog dialog = new Dialog(holder.itemView.getContext());

                dialog.requestWindowFeature(Window.FEATURE_NO_TITLE);
                dialog.setCanceledOnTouchOutside(false);
                dialog.setCancelable(true);
                dialog.setContentView(R.layout.activity_fullscreen_image);

                ImageView back=(ImageView)dialog.findViewById(R.id.back);
                ViewPager viewPagerPhotoSlideShow = (ViewPager) dialog.findViewById(R.id.pager);

                ArrayList<String> pagerListItems=new ArrayList<String>();
                pagerListItems.add(0,"https://firebasestorage.googleapis.com/v0/b/zumi-60a8f.appspot.com/o/Chat_Images%2Fcropped-1222406361.png?alt=media&token=22b8673f-5602-48d4-980f-986d505d2d8f");
                pagerListItems.add(1,"https://firebasestorage.googleapis.com/v0/b/zumi-60a8f.appspot.com/o/Chat_Images%2Fcropped1611377016.png?alt=media&token=e7a40c6c-35ad-48ee-80ca-656384fcf68c");

                FullScreenImageAdapter adapterPhotoViewPager = new FullScreenImageAdapter(dialog.getOwnerActivity(), pagerListItems);
                viewPagerPhotoSlideShow.setAdapter(adapterPhotoViewPager);
                viewPagerPhotoSlideShow.setCurrentItem(0);


                back.setOnClickListener(new View.OnClickListener() {
                    @Override
                    public void onClick(View v) {
                        dialog.cancel();
                    }
                });


                WindowManager.LayoutParams lp = new WindowManager.LayoutParams();
                lp.copyFrom(dialog.getWindow().getAttributes());
                lp.width = WindowManager.LayoutParams.MATCH_PARENT;
                lp.height = WindowManager.LayoutParams.MATCH_PARENT;
                lp.gravity = Gravity.CENTER;

                Window window = dialog.getWindow();
                window.setAttributes(lp);
                window.setBackgroundDrawable(new ColorDrawable(Color.TRANSPARENT));
                dialog.show();

            }
        });

public class FullScreenImageAdapter extends PagerAdapter {

    private Activity _activity;
    private ArrayList<String> _imagePaths;
    private LayoutInflater inflater;

    // constructor
    public FullScreenImageAdapter(Activity activity,
                                  ArrayList<String> imagePaths) {
        this._activity = activity;
        this._imagePaths = imagePaths;
    }

    @Override
    public int getCount() {
        return this._imagePaths.size();
    }

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

    @Override
    public Object instantiateItem(ViewGroup container, int position) {
        ImageView imgDisplay;
      //  Button btnClose;

        inflater = (LayoutInflater) _activity
                .getSystemService(Context.LAYOUT_INFLATER_SERVICE);


        View viewLayout = inflater.inflate(R.layout.layout_fullscreen_image_each, container,
                false);

        imgDisplay = (ImageView) viewLayout.findViewById(R.id.imgDisplay);

        Glide.with(container.getContext()).load(_imagePaths.get(0))
                .priority(Priority.HIGH).animate(android.R.anim.fade_in)
                .override(120, 87).fitCenter().skipMemoryCache(false)
                .diskCacheStrategy(DiskCacheStrategy.RESULT)
                .into(imgDisplay);

        ((ViewPager) container).addView(viewLayout);

        return viewLayout;
    }

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

    }

}

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:orientation="vertical" >

    <ImageView
        android:layout_width="30dp"
        android:layout_height="30dp"
        android:src="@drawable/arrow"
        android:rotation="180"
        android:id="@+id/back"/>

    <android.support.v4.view.ViewPager
        android:id="@+id/pager"
        android:layout_width="fill_parent"
        android:layout_height="fill_parent" />


</LinearLayout>

<?xml version="1.0" encoding="utf-8"?>
<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
    android:layout_width="match_parent"
    android:layout_height="match_parent" >

    <ImageView
        android:id="@+id/imgDisplay"
        android:layout_width="fill_parent"
        android:layout_height="fill_parent"
        android:scaleType="fitCenter" />

</RelativeLayout>

错误>>>

E/AndroidRuntime：致命异常：main process：com.example.cosmic.zumi_test,pid：22289 java.lang.nullpointerException：试图在Android.support.v4的Android.support.v4的Android.cosmic.zumi_test.from(layoutInflater.java.219)和Android.support.v4.view.viewpager.addnewitem（viewpager.java:1034)上的空对象引用上调用虚拟方法'java.lang.object在Android.support.v4.view.view.viewpager.populate(ViewPager.java:1182)，在Android.support.v4.view.viewPager.populate(ViewPager.java:1116)，在Android.support.v4.view.viewPager.onMeasure(ViewPager.java:1642)在Android.view.view.viewPager.onMeasure(ViewPager.java:1642)，在Android.view.view.viewGroup.Measure奥尼梅苏在Android.view.view.measur(view.java:17572)，在Android.view.viewgroup.measureChildWithMargins（viewgroup.java:5604)，在Android.widget.frameLayout.onMeasur(frameLayout.java:436)，在Android.view.viewgroup.measureChildWithMargins（viewgroup.java:436，在Android.view.viewgroup.measureChildWithMargins（:5604)在Android.widget.frameLayout.onMeasure（frameLayout.java:436)在com.android.internal.policy.impl.phoneWindow$decorview.onMeasure（phoneWindow.java:2632)在Android.view.view.view.measure（view.java:17572)在Android.view.viewrootimpl.measure（view.java:1752)在Android.view.viewrootimpl.measure（view.java:1173在Android.view.ViewRootimpl$traversalrunnable.run(viewrootimpl.java:5895)在Android.view.choreographer$CallbackRecord.run(choreographer.java:767)在Android.view.choreographer.docallbacks（choreographer.java:580)在Android.view.choreographer.java:550)在Android.view.choreographer.doFrame（choreographer.java:550)在id.os.looper.loop(looper.java:135)，地址为Android.app.activitythread.main（activitythread.java:5345)，地址为java.lang.reflect.Method.invoke（本机方法），地址为java.lang.reflect.Method.invoke(Method.java:372)，地址为com.android.internal.os.zygoteinit.run(zygoteinit.jam(zygoteinit.java:742)。

Answer 1

似乎_activity在FullScreenImageAdapter中为空。这是因为dialog.getowneractivity()是null（正如@dipdipdip所说）。不要像您那样实例化视图分页程序适配器，请尝试这样做：

FullScreenImageAdapter adapterPhotoViewPager = new FullScreenImageAdapter(v.getContext(), pagerListItems);

更新

若要在对话框中显示不同的图像，请按以下方式更改页适配器中的InstantiateItem方法：

@Override
public Object instantiateItem(ViewGroup container, int position) {
    ImageView imgDisplay;
  //  Button btnClose;

    inflater = (LayoutInflater) _activity
            .getSystemService(Context.LAYOUT_INFLATER_SERVICE);


    View viewLayout = inflater.inflate(R.layout.layout_fullscreen_image_each, container,
            false);

    imgDisplay = (ImageView) viewLayout.findViewById(R.id.imgDisplay);

    Glide.with(container.getContext()).load(_imagePaths.get(position))
            .priority(Priority.HIGH).animate(android.R.anim.fade_in)
            .override(120, 87).fitCenter().skipMemoryCache(false)
            .diskCacheStrategy(DiskCacheStrategy.RESULT)
            .into(imgDisplay);

    ((ViewPager) container).addView(viewLayout);

    return viewLayout;
}