如何从 ViewPager 更改子片段 imageView

Question

我有ViewPager和4个片段。片段 2 称为 StatusFragment。在那个 StatusFragment 我有一个 ImageView。在 ViewPager 中，我得到了 bundle 的字符串，这是一个图像路径。我成功地获得了我的包，但现在我需要用位图解码我的路径并将其添加到 StatusFragment 的 ImageView 中。我尝试从 StatusFragment public 执行 ImageView，然后将其从 ViewPager 更改，但结果是 NullPointerException。如何从 ViewPager 更改该图像？谢谢。

这里是 ViewPager 代码。

public class SlidePageTabsMainFragment extends BaseFragment {
private View mainView;
private TabLayout mTabs;
private ViewPager mPage;
private FragmentActivity myContext;
private CoordinatorLayout coordinatorLayout;
private StatusFragment statusFragment;

@Override
public View onCreateView(LayoutInflater inflater, ViewGroup container, Bundle savedInstanceState) {
    mainView = inflater.inflate(R.layout.slide_page_tabs_main_fragment, container, false);
    mTabs = (TabLayout) mainView.findViewById(R.id.tab_layout);
    mPage = (ViewPager) mainView.findViewById(R.id.view_pager);
    coordinatorLayout = (CoordinatorLayout) mainView.findViewById(R.id.coordinator_layout_id);

    mPage.setOffscreenPageLimit(3);

    //mTabs.setupWithViewPager(mPage);
    SetUpViewPager();
    getTabLayoutLocation();
    setmFloatingActionButtons();

    Bundle getBundleImagePath = getArguments();
    if(getBundleImagePath != null){
        String getImagePaths = getBundleImagePath.getString("imagePath");
        Toast.makeText(myContext, getImagePaths, Toast.LENGTH_SHORT).show();

        Bitmap imageBitmap = BitmapFactory.decodeFile(getImagePaths);
        //statusFragment.photoId.setImageBitmap(imageBitmap);

        mPage.setCurrentItem(1);
    }
    return mainView;
}
}

@Override
public String toString() {
    return "SlidePageTabsMainFragment";
}

public void SetUpViewPager() {
    //Add fragments
    SlidePageTabsAdapter adapter = new SlidePageTabsAdapter(getChildFragmentManager());
    adapter.addFragment(new SupportopFragment());
    adapter.addFragment(new StatusFragment());
    adapter.addFragment(new ConnectionsFragment());
    adapter.addFragment(new SupportersFragment());

    //Setting adapter
    mPage.setAdapter(adapter);
    mTabs.setupWithViewPager(mPage);

    //Setting icons in tabs
    mTabs.getTabAt(0).setIcon(R.drawable.supportop_icon);
    mTabs.getTabAt(1).setIcon(R.drawable.repair_icon);
    mTabs.getTabAt(2).setIcon(R.drawable.transport_icon);
    mTabs.getTabAt(3).setIcon(R.drawable.security_icon);
    //mPage.addOnPageChangeListener(new TabLayout.TabLayoutOnPageChangeListener(mTabs));

    mPage.addOnPageChangeListener(pageChangeListener);

    // mTabs.addOnTabSelectedListener(new TabLayout.ViewPagerOnTabSelectedListener(mPage));

}
}

好的，那是一个有点大的代码，但我想你已经理解了。

现在我将添加 StatusFragment。

public class StatusFragment extends BaseFragment {

private View mainView;
public ImageView photoId;
private SlidePageTabsMainFragment slidePages;

public StatusFragment() {};

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

    mainView = inflater.inflate(R.layout.status_fragment, container, false);

    photoId = (ImageView) mainView.findViewById(R.id.photo_id);
    slidePages = new SlidePageTabsMainFragment();

    return mainView;
}

@Override
public String toString() {
    return "StatusFragment";
}
}

好的，现在当您观看代码时，如果我在 ViewPager 中获取捆绑包，我该如何从 ViewPager 更改 photoId 图像？不要说要在 StatusFragment 中获取捆绑包。我只需要在 ViewPager 中获取它。谢谢。

Answer 1

只需将包含位图的 StatusFragment 捆绑到其中。 Bitmap 实现了 Parcelable，因此它可以存储在 Bundle 中：

在SlidePageTabsMainFragment

public void setUpViewPager(Bitmap b) {
    Bundle args = new Bundle();
    args.putParcelable("image", b);
    //... your code
    // Add arguments to the Fragment
    Fragment statusFragment = new StatusFragment();
    statusFragment.setArguments(args);

    //...   
    adapter.addFragment(statusFragment);
    //...
}

在 StatusFragment

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

    mainView = inflater.inflate(R.layout.status_fragment, container, false);

    photoId = (ImageView) mainView.findViewById(R.id.photo_id);

    // Get the Bitmap and set it to the ImageView
    Bundle bundle = getArguments();
    Bitmap image = (Bitmap) bundle.getParcelable("image");
    photoId.setImageBitmap(image);

    slidePages = new SlidePageTabsMainFragment();

    return mainView;
}

如何从 ViewPager 更改子片段 imageView

How to change child fragment imageView from ViewPager

android

bundle

android-fragments

android-viewpager