Question

我是android的新手，我想在一个已经扩展到Fragment的类中添加一个带点指示符的图像滑块。我想在fragment_about_sl.xml中添加图像滑块（代码如下所示）和后端在aboutSLFragment.java（代码如下所示）中。我怎么能这样做，请告诉我要实现的完整代码。

fragment_about_sl.xml

<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:tools="http://schemas.android.com/tools"
android:layout_width="match_parent"
android:layout_height="match_parent">

<!-- TODO: Update blank fragment layout -->

<TextView
    android:layout_width="wrap_content"
    android:layout_height="wrap_content"
    android:text="hkjhkjhkjhk"/>
</LinearLayout>

aboutSLFragment.java

public class aboutSLFragment extends Fragment {



public aboutSLFragment() {
    // Required empty public constructor
}


@Override
public View onCreateView(LayoutInflater inflater, ViewGroup container,
                         Bundle savedInstanceState) {
    // Inflate the layout for this fragment
    return inflater.inflate(R.layout.fragment_about_sl, container, false);
}

@Override
public void onViewCreated(View view, @Nullable Bundle savedInstanceState) {
    super.onViewCreated(view, savedInstanceState);
    //you can set the title for your toolbar here for different fragments different titles
    getActivity().setTitle("About Sri Lanka");
}

}

我已将aboutSLFragment.java扩展到Fragment，因为我在创建导航抽屉时使用了片段。请告诉我添加到xml和java类的内容。谢谢！

我已将图像滑块添加到我的班级但红色中有一些错误。任何人都可以提供帮助。我已经加粗了红色错误。 public class aboutSLFragment扩展了Fragment {

ViewPager viewPager;
LinearLayout sliderDotspanel;
private int dotscount;
private ImageView[] dots;


public aboutSLFragment() {
    // Required empty public constructor
}


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

    viewPager = (ViewPager) **findViewById**(R.id.viewPager);

    sliderDotspanel = (LinearLayout) **findViewById**(R.id.SliderDots);

    ViewPagerAdapter viewPagerAdapter = new ViewPagerAdapter(**this**);

    viewPager.setAdapter(viewPagerAdapter);

    dotscount = viewPagerAdapter.getCount();
    dots = new ImageView[dotscount];

    for(int i = 0; i < dotscount; i++){

        dots[i] = new ImageView(**this**);
        dots[i].setImageDrawable(ContextCompat.getDrawable(**getApplicationContext()**, R.drawable.non_active_dot));

        LinearLayout.LayoutParams params = new LinearLayout.LayoutParams(LinearLayout.LayoutParams.WRAP_CONTENT, LinearLayout.LayoutParams.WRAP_CONTENT);

        params.setMargins(8, 0, 8, 0);

        sliderDotspanel.addView(dots[i], params);

    }

    dots[0].setImageDrawable(ContextCompat.getDrawable(**getApplicationContext()**, R.drawable.active_dot));

    viewPager.addOnPageChangeListener(new ViewPager.OnPageChangeListener() {
        @Override
        public void onPageScrolled(int position, float positionOffset, int positionOffsetPixels) {

        }

        @Override
        public void onPageSelected(int position) {

            for(int i = 0; i< dotscount; i++){
                dots[i].setImageDrawable(ContextCompat.getDrawable(**getApplicationContext()**, R.drawable.non_active_dot));
            }

            dots[position].setImageDrawable(ContextCompat.getDrawable(**getApplicationContext()**, R.drawable.active_dot));

        }

        @Override
        public void onPageScrollStateChanged(int state) {

        }
    });

    // Inflate the layout for this fragment
    return inflater.inflate(R.layout.fragment_about_sl, container, false);
}

@Override
public void onViewCreated(View view, @Nullable Bundle savedInstanceState) {
    super.onViewCreated(view, savedInstanceState);
    //you can set the title for your toolbar here for different fragments different titles
    getActivity().setTitle("About Sri Lanka");
}

}

Answer 1

以下是您编辑的代码形式

ViewPager viewPager;
LinearLayout sliderDotspanel;
private int dotscount;
private ImageView[] dots;


public aboutSLFragment() {
    // Required empty public constructor
}


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

    View view = inflater.inflate(R.layout.fragment_about_sl, container, false);

    viewPager = (ViewPager) view.findViewById(R.id.viewPager);

    sliderDotspanel = (LinearLayout) view.findViewById(R.id.SliderDots);

    ViewPagerAdapter viewPagerAdapter = new ViewPagerAdapter(getActivity());

    viewPager.setAdapter(viewPagerAdapter);

    dotscount = viewPagerAdapter.getCount();
    dots = new ImageView[dotscount];

    for(int i = 0; i < dotscount; i++){

        dots[i] = new ImageView(getActivity());
        dots[i].setImageDrawable(ContextCompat.getDrawable(getActivity().getApplicationContext(), R.drawable.non_active_dot));

        LinearLayout.LayoutParams params = new LinearLayout.LayoutParams(LinearLayout.LayoutParams.WRAP_CONTENT, LinearLayout.LayoutParams.WRAP_CONTENT);

        params.setMargins(8, 0, 8, 0);

        sliderDotspanel.addView(dots[i], params);

    }

    dots[0].setImageDrawable(ContextCompat.getDrawable(getActivity().getApplicationContext(), R.drawable.active_dot));

    viewPager.addOnPageChangeListener(new ViewPager.OnPageChangeListener() {
        @Override
        public void onPageScrolled(int position, float positionOffset, int positionOffsetPixels) {

        }

        @Override
        public void onPageSelected(int position) {

            for(int i = 0; i< dotscount; i++){
                dots[i].setImageDrawable(ContextCompat.getDrawable(getActivity().getApplicationContext(), R.drawable.non_active_dot));
            }

            dots[position].setImageDrawable(ContextCompat.getDrawable(getActivity().getApplicationContext(), R.drawable.active_dot));

        }

        @Override
        public void onPageScrollStateChanged(int state) {

        }
    });

    // Inflate the layout for this fragment
    return view;
}

@Override
public void onViewCreated(View view, @Nullable Bundle savedInstanceState) {
    super.onViewCreated(view, savedInstanceState);
    //you can set the title for your toolbar here for different fragments different titles
    getActivity().setTitle("About Sri Lanka");
}

}

如何在片段中添加带点指示符的图像滑块？

1 个答案: