android - Toast 类型中的方法 makeText 不适用于参数

Question

当我们滚动到下一个片段页面时，我正在使用 ViewPageIndicator 并尝试使用 Toast 来显示。

我让他跟随错误

The method makeText(Context, CharSequence, int) in the type Toast is not applicable for the arguments (PlaceDetailsFragment, String, int)

PlaceDetailsFragment.java

public class PlaceDetailsFragment extends SherlockFragment {
    ImageFragmentAdapter mAdapter;
    ViewPager mPager;
    PageIndicator mIndicator;

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

        mAdapter = new ImageFragmentAdapter(getActivity()
                .getSupportFragmentManager());

        mPager = (ViewPager) view.findViewById(R.id.pager);
        mPager.setAdapter(mAdapter);

        mIndicator = (CirclePageIndicator) view.findViewById(R.id.indicator);
        mIndicator.setViewPager(mPager);
        ((CirclePageIndicator) mIndicator).setSnap(true);

        mIndicator.setOnPageChangeListener(new ViewPager.OnPageChangeListener() {
            @Override
            public void onPageSelected(int position) {
                Toast.makeText(PlaceDetailsFragment.this, "Changed to page " + position, Toast.LENGTH_SHORT).show();
            }

            @Override
            public void onPageScrolled(int position, float positionOffset, int positionOffsetPixels) {
            }

            @Override
            public void onPageScrollStateChanged(int state) {
            }
        });
        return view;
    }

}

Answer 1

片段不扩展上下文。您必须让活动作为上下文传递。

Toast.makeText(PlaceDetailsFragment.this.getActivity(), "Changed to page " + position, Toast.LENGTH_SHORT).show();

Answer 2

PearsonArtFoto 已经给了你答案，但我想补充一些信息：你必须使用 getActivity() 因为你不是在 Activity（或扩展 Activity 的东西）中调用它。活动是一个上下文（它扩展了上下文），片段不是。

Answer 3

使用片段的容器参数

Toast.makeText(container.getContext(), picture, Toast.LENGTH_LONG).show();