android - 在对话框中使用 ViewPager 的最佳做法是什么

Question

我正在尝试在对话框中显示一个 viewPager。所以首先我尝试了一个简单的对话框，我没有得到任何错误，但是一个空的 View ，我不知道为什么。然后我读到:a viewPager can't work with a normal Dialog you need to use a DialogFragment。

所以现在我正在使用 DialogFragment，但我仍然遇到同样的问题，没有 ViewPager，我只有我的对话框的 RelativeLayout，它显示但为空。

这是我的 DialogFragment:

public class NewFeatureDialog extends DialogFragment {

    private Activity activity;
    private Dialog newFeatureDialog;
    private ViewPager viewPager;
    private NewFeatureAdapter adapter;
    private ArrayList<NewFeature> nfList;
    private View view;

    public NewFeatureDialog(Activity activity) {
        this.activity = activity;
    }

    @Override
    public View onCreateView(LayoutInflater inflater, ViewGroup container, Bundle savedInstanceState) {
        view = inflater.inflate(R.layout.dialog_new_features, container);
        return view;
    }

    @Override
    public void onActivityCreated(Bundle savedInstanceState) {
        super.onActivityCreated(savedInstanceState);

        fillNewFeatureList();// create my list of data

        setUi();
    }

    private void setUi() {
        viewPager = (ViewPager)view.findViewById(R.id.view_pager_new_feature);
        adapter = new NewFeatureAdapter(activity, nfList);
        viewPager.setAdapter(adapter);
        viewPager.setCurrentItem(0);
    }
}

对话框布局:

<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
    android:layout_width="wrap_content"
    android:layout_height="wrap_content"
    android:background="@drawable/bg_demo_area"
    android:orientation="vertical">

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

</RelativeLayout>

ViewPager 适配器:

public class NewFeatureAdapter extends PagerAdapter {

    private Activity activity;
    private ArrayList<NewFeature> newFeatureList;
    private LayoutInflater layoutInflater;

    public NewFeatureAdapter(Activity activity, ArrayList<NewFeature> newFeatureList) {
        this.activity = activity;
        this.newFeatureList = newFeatureList;
    }

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

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

    @Override
    public Object instantiateItem(ViewGroup container, int position) {

        layoutInflater = LayoutInflater.from(activity);
        View view = layoutInflater.inflate(R.layout.item_new_feature, container, false);

        ImageView featureScreen = (ImageView) view.findViewById(R.id.image_new_feature);
        TextView featureTitle = (TextView) view.findViewById(R.id.new_feature_title);
        TextView featureDescription = (TextView) view.findViewById(R.id.description_new_feature);

        NewFeature newFeature = newFeatureList.get(position);
        if (newFeature != null) {
            if (featureScreen != null) {
                featureScreen.setImageResource(newFeature.getResourceImage());
            }
            if (featureTitle != null) {
                featureTitle.setText(newFeature.getName());
            }
            if (featureDescription != null) {
                featureDescription.setText(newFeature.getDescription());
            }
        }
        return view;
    }

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

这里似乎一切正常。我没有任何空值或其他错误，但我的应用程序的对话框中没有显示任何内容。

我的 Activity 扩展了 Activity，我只是像这样在 dialoFragment 中使用:

FragmentManager fragmentManager = getFragmentManager();
NewFeatureDialog dialog = new NewFeatureDialog(this);
dialog.show(fragmentManager,"dialogFragment");

做我想做的事情的最佳做法是什么？是否可以使用普通对话框来显示 viewPager ？

Answer 1

所以我在这里找到了解决该问题的方法。

事实上，我忘记了 instantiateItem(..) 方法中的一行，相对于在适配器中创建的 View 需要像这样附加到我的 viewPager 容器的那一刻:

container.addView(view, 0);

这是我的 instantiateItem(..) 方法:

    @Override
    public Object instantiateItem(ViewGroup container, int position) {

        layoutInflater = (LayoutInflater) container.getContext().getSystemService(Context.LAYOUT_INFLATER_SERVICE);
        View view = layoutInflater.inflate(R.layout.item_new_feature, container, false);

        ImageView featureScreen = (ImageView) view.findViewById(R.id.image_new_feature);
        TextView featureTitle = (TextView) view.findViewById(R.id.new_feature_title);
        TextView featureDescription = (TextView) view.findViewById(R.id.description_new_feature);

        NewFeature newFeature = newFeatureList.get(position);
        if (newFeature != null) {
            if (featureScreen != null) {
                featureScreen.setImageResource(newFeature.getResourceImage());
            }
            if (featureTitle != null) {
                featureTitle.setText(newFeature.getName());
            }
            if (featureDescription != null) {
                featureDescription.setText(newFeature.getDescription());
            }
        }
        container.addView(view, 0);
        return view;
    }

我检查过你可以在对话框中使用它，也可以在 fragment 中使用它，它工作正常。