Question

我正在尝试从Recycler View图像打开一个对话框单击...对话框包含一个Viewpager来制作一个刷卡视图库..

打开对话框的代码

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();

            }
        });

适配器代码：

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＆gt;＆gt;

<?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>

每个视图的XML

<?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＆gt;＆gt;＆gt;

E / AndroidRuntime：致命异常：主要处理：com.example.cosmic.zumi_test，PID：22289 java.lang.NullPointerException：尝试调用虚方法＆＃39; java.lang.Object中 android.content.Context.getSystemService（java.lang.String中）＆＃39;在null 对象参考在android.view.LayoutInflater.from（LayoutInflater.java:219）在 com.example.cosmic.zumi_test.FullScreenImageAdapter.instantiateItem（FullScreenImageAdapter.java:56）在android.support.v4.view.ViewPager.addNewItem（ViewPager.java:1034）在android.support.v4.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.measure（View.java:17572）在android.view.ViewGroup.measureChildWithMargins（ViewGroup.java:5604）在 android.widget.LinearLayout.measureChildBeforeLayout（LinearLayout.java:1436）在android.widget.LinearLayout.measureVertical（LinearLayout.java:722）在android.widget.LinearLayout.onMeasure（LinearLayout.java:613）在android.view.View.measure（View.java:17572）在android.view.ViewGroup.measureChildWithMargins（ViewGroup.java:5604）在android.widget.FrameLayout.onMeasure（FrameLayout.java:436）在android.view.View.measure（View.java:17572）在android.view.ViewGroup.measureChildWithMargins（ViewGroup.java:5604）在android.widget.FrameLayout.onMeasure（FrameLayout.java:436）在android.view.View.measure（View.java:17572）在android.view.ViewGroup.measureChildWithMargins（ViewGroup.java: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.measure（View.java:17572）在android.view.ViewRootImpl.performMeasure（ViewRootImpl.java:2015）在android.view.ViewRootImpl.measureHierarchy（ViewRootImpl.java:1173）在android.view.ViewRootImpl.performTraversals（ViewRootImpl.java:1379）在android.view.ViewRootImpl.doTraversal（ViewRootImpl.java:1061）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.doFrame（Choreographer.java:550）在 android.view.Choreographer $ FrameDisplayEventReceiver.run（Choreographer.java:753）在android.os.Handler.handleCallback（Handler.java:739）在android.os.Handler.dispatchMessage（Handler.java:95）在android.os.Looper.loop（Looper.java:135）在android.app.ActivityThread.main（ActivityThread.java:5345） at java.lang.reflect.Method.invoke（Native Method）在java.lang.reflect.Method.invoke（Method.java:372）在 com.android.internal.os.ZygoteInit $ MethodAndArgsCaller.run（ZygoteInit.java:947）在com.android.internal.os.ZygoteInit.main（ZygoteInit.java:742）

Answer 1

在创建对话框之前，它没有“所有者”。因此，调用dialog.getOwnerActivity()会返回null。

只是提示：您无需将Activity传递到适配器。

在instantiateItem中，只需使用容器中的Context来接收LayoutInflater：

LayoutInflater inflater = LayoutInflater.from(container.getContext());

Answer 2

_activity内的FullScreenImageAdapter似乎为空。这是因为dialog.getOwnerActivity()为空（如前所述@dipdipdip）。不要像你那样实例化视图寻呼机适配器，而是尝试这种方式：

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

<强>更新

要在对话框中显示不同的图像，请以这种方式更改寻呼机适配器内的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;
}

Viewpager

2 个答案: