java如何在触摸事件中停止图像滑块的自动滚动

Question

我已经使用自定义ViewPager创建了一个自动图像滑块。现在我想知道如何停止触摸时图像的自动滑动，并在释放触摸时从左侧再次启动滑块

这是我的CustomViewPager。爪哇：-

public class CustomViewPager extends ViewPager {

    private boolean isPagingEnabled = true;

    public CustomViewPager(Context context) {
        super(context);
    }

    public CustomViewPager(Context context, AttributeSet attrs) {
        super(context, attrs);
    }

    @Override
    public boolean onTouchEvent(MotionEvent event) {

        return this.isPagingEnabled && super.onTouchEvent(event);
    }

    @Override
    public boolean onInterceptTouchEvent(MotionEvent event) {
        return this.isPagingEnabled && super.onInterceptTouchEvent(event);
    }

    public void setPagingEnabled(boolean b) {
        this.isPagingEnabled = b;
    }


}

这是ImageAdapter。爪哇：-

public  class SlidingImage_Adapter extends PagerAdapter {


    Context context;
    int images[];
    LayoutInflater inflater;


    public SlidingImage_Adapter(Context context, int images[]) {

        this.context = context;
        this.images = images;
        inflater = (LayoutInflater)context.getSystemService(Context.LAYOUT_INFLATER_SERVICE);
    }



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

    @Override
    public int getCount() {
        return images.length;
    }

    @Override
    public Object instantiateItem(ViewGroup container, final int position) {
        View itemView = inflater.inflate(R.layout.sliding_images, container, false);


        final ImageView imageView = (ImageView) itemView
                .findViewById(R.id.image);


        imageView.setImageResource(images[position]);

        container.addView(itemView, 0);

        return itemView;
    }

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

    @Override
    public void restoreState(Parcelable state, ClassLoader loader) {
    }

    @Override
    public Parcelable saveState() {
        return null;
    }

}

这是碎片。使用此CustomViewPager的java：-

public class HomeFragment extends Fragment {

    private static final String ARG_PARAM1 = "param1";
    private static final String ARG_PARAM2 = "param2";
    TextView tv_slider, tv_button;
    RelativeLayout dummyView;
    CustomViewPager mViewPager;

    Timer timer;
    final long DELAY_MS = 1000;//delay in milliseconds before task is to be executed
    final long PERIOD_MS = 3000;



    private static int currentPage = 0;
    private static int NUM_PAGES = 0;
     int images[] = {R.drawable.ecommerce, R.drawable.digital_marketing, R.drawable.explainer, R.drawable.it_services,
            R.drawable.mobile_app, R.drawable.seo, R.drawable.software, R.drawable.webdesign};
    SlidingImage_Adapter imageAdapter;


    // TODO: Rename and change types of parameters
    private String mParam1;
    private String mParam2;

    private OnFragmentInteractionListener mListener;

    public HomeFragment() {

    }

    public static HomeFragment newInstance(String param1, String param2) {
        HomeFragment fragment = new HomeFragment();
        Bundle args = new Bundle();
        args.putString(ARG_PARAM1, param1);
        args.putString(ARG_PARAM2, param2);
        fragment.setArguments(args);
        return fragment;
    }

    @Override
    public void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        if (getArguments() != null) {
            mParam1 = getArguments().getString(ARG_PARAM1);
            mParam2 = getArguments().getString(ARG_PARAM2);


        }
    }


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

         tv_slider=(TextView)v.findViewById(R.id.tv_slider);
         tv_slider.setTypeface(EasyFonts.robotoLight(this.getActivity()));
         tv_button=(TextView)v.findViewById(R.id.tv_button);
         tv_button.setTypeface(EasyFonts.robotoLight(this.getActivity()));


        mViewPager = (CustomViewPager) v.findViewById(R.id.pager);
        imageAdapter = new SlidingImage_Adapter(getActivity(),images);
        mViewPager.setAdapter(imageAdapter);




        final Handler handler = new Handler();
        final Runnable Update = new Runnable() {
           public void run() {
                if (currentPage == NUM_PAGES) {
                    currentPage = 0;
                }
                mViewPager.setCurrentItem(currentPage++, true);

            }
        };

                Timer swipeTimer = new Timer();
       swipeTimer.schedule(new TimerTask() {
            @Override
           public void run() {
               handler.post(Update);
           }
       }, DELAY_MS, PERIOD_MS);






        CirclePageIndicator indicator = (CirclePageIndicator)
                v.findViewById(R.id.indicator);

        indicator.setViewPager(mViewPager);

        final float density = getResources().getDisplayMetrics().density;

         //Set circle indicator radius
        indicator.setRadius(3 * density);

        NUM_PAGES =images.length;



        // Pager listener over indicator
        indicator.setOnPageChangeListener(new CustomViewPager.OnPageChangeListener() {

            @Override
            public void onPageSelected(int position) {
                currentPage = position;

            }



            @Override
            public void onPageScrolled(int pos, float arg1, int arg2) {

                switch (pos){

                    case 0:
                        tv_slider.setText(getString(R.string.es_content));
                        break;

                    case 1:
                        tv_slider.setText(getString(R.string.dm_content));
                        break;

                    case 2:
                        tv_slider.setText(getString(R.string.ev_content));
                        break;

                    case 3:
                        tv_slider.setText(getString(R.string.it_content));
                        break;

                    case 4:
                        tv_slider.setText(getString(R.string.md_content));
                        break;

                    case 5:
                        tv_slider.setText(getString(R.string.seo_content));
                        break;

                    case 6:
                        tv_slider.setText(getString(R.string.sd_content));
                        break;

                    case 7:
                        tv_slider.setText(getString(R.string.wd_content));
                        break;

                }



            }

            @Override
            public void onPageScrollStateChanged(int pos) {

            }
        });


        return v;


    }

Answer 1

我发现了一个第三方库"Library Link"，它具有启动和停止自动滚动的内置方法

Answer 2

这是我的示例代码，运行良好=>

public class MainActivity extends AppCompatActivity {

    final long DELAY_MS = 1000;//delay in milliseconds before task is to be executed
    final long PERIOD_MS = 3000;
    int currentPage = 0;
    public Timer timer;
    public Timer swipeTimer;
    public static boolean startSlider = true;
    public TextView textView;
    public LinearLayout layout;

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);
        textView = (TextView) findViewById(R.id.textView);
        layout = (LinearLayout) findViewById(R.id.layout);

        final Handler handler = new Handler();
        final Runnable Update = new Runnable() {
            public void run() {

                if (currentPage == 6) {
                    currentPage = 0;
                }
                currentPage++;
                textView.setText(String.valueOf(currentPage));

            }
        };


        swipeTimer = new Timer();
        swipeTimer.schedule(new TimerTask() {
            @Override
            public void run() {
                if (startSlider){
                    handler.post(Update);
                }

            }
        }, DELAY_MS, PERIOD_MS);

        layout.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View v) {
                if (startSlider){
                    startSlider = false;
                }else {
                    startSlider = true;
                }
            }
        });

    }

}

Answer 3

根据this文档，您已经覆盖的onTouchEvent是查看的地方

现在不要叫超级。再次使用onTouchEvent（事件），就像您在方法中所做的那样。实现您自己的自定义操作。通过调用super，您接受了默认行为