13

我现在使用 android view pager 来显示图像和文本我想要的是，如果用户没有更改图像，那么它应该在几秒钟后开始自动更改图像，当用户再次开始使用他的手指然后图像不应该自动改变吗？

我尝试使用处理程序来创建延迟，但它对我不起作用？

请帮助任何人

public class SimpleImageViewerActivity  extends Activity implements ViewPager.OnPageChangeListener{
    private Handler handler;
    ViewPager myPager;
    @Override
    public void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.imageslideshow);
        MyPagerAdapter adapter = new MyPagerAdapter();
        myPager = (ViewPager) findViewById(R.id.slideShowPager);
        myPager.setAdapter(adapter);
        myPager.setCurrentItem(0);

        handler = new Handler();
    myPager.setOnPageChangeListener(this);
    }

    private class MyPagerAdapter extends PagerAdapter {

        public int getCount() {
            return 5;
        }

        public Object instantiateItem(View collection, int position) {

            LayoutInflater inflater = (LayoutInflater) collection.getContext()
                    .getSystemService(Context.LAYOUT_INFLATER_SERVICE);

            int resId = 0;
            switch (position) {
            case 0:
                resId = R.layout.farleft;
                break;
            case 1:
                resId = R.layout.left;
                break;
            case 2:
                resId = R.layout.middle;
                break;
            case 3:
                resId = R.layout.right;
                break;
            case 4:
                resId = R.layout.farright;
                break;
            }

            View view = inflater.inflate(resId, null);

            ((ViewPager) collection).addView(view, 0);

            return view;
        }

        @Override
        public void destroyItem(View arg0, int arg1, Object arg2) {
            ((ViewPager) arg0).removeView((View) arg2);

        }

        @Override
        public void finishUpdate(View arg0) {
            // TODO Auto-generated method stub

        }

        @Override
        public boolean isViewFromObject(View arg0, Object arg1) {
            return arg0 == ((View) arg1);

        }

        @Override
        public void restoreState(Parcelable arg0, ClassLoader arg1) {
            // TODO Auto-generated method stub

        }

        @Override
        public Parcelable saveState() {
            // TODO Auto-generated method stub
            return null;
        }

        @Override
        public void startUpdate(View arg0) {
            // TODO Auto-generated method stub

        }


    }

    @Override
    public void onPageScrollStateChanged(int arg0) {
        // TODO Auto-generated method stub

    }

    @Override
    public void onPageScrolled(int arg0, float arg1, int arg2) {
        // TODO Auto-generated method stub

        updateUI(arg2);
    }

    @Override
    public void onPageSelected(int arg0) {
        // TODO Auto-generated method stub
        //updateUI(arg0);

    }

    public void onNothingSelected(AdapterView<?> adapterView) {    
        final int i =0;
        adapterView.postDelayed(new Runnable(){

            @Override
            public void run() {
                // TODO Auto-generated method stub
                updateUI(i);            
            }

        }, 5000);
        Toast.makeText(this, "In nothing selected method",Toast.LENGTH_SHORT).show();




    }

    private void updateUI(final int fi) {
           /* handler.post(new Runnable() {
                public void run() {
                    gallery.setSelection(i);
                    viewPager.setCurrentItem(i);

                    //textView.setText("Photo #" + i);
                }
            });*/
            handler.postDelayed(new Runnable() {
                public void run() {
                    int i=fi;
                    int j = i;
                    myPager.setCurrentItem(j++);
                    System.out.println("Hello");             

                }
            },1000);
        }   


}
4

3 回答 3

3

使用 javautil timer 并设置一个，在计时器结束时您可以使用

class UpdateTimeTask extends TimerTask {
   public void run() {
    //Code for the viewPager to change view
  }
 }


 // Code to schedule the timer
 timer = new Timer();
 timer.schedule(new UpdateTimeTask(), 100, 200);

希望这会有所帮助，请使用 android 文档进行准确的 API 调用

<ViewPager>.setCurrentitem(i++%<MaxViews>)
于 2012-04-06T11:12:16.013 回答
0

就 UI 更新而言，您可以通过处理程序来完成，因此在 timertask 类中调用处理程序，您可以执行以下操作：

Timer timer=null;
static int time_tomove = 0;

class UpdateTimeTask extends TimerTask {
       public void run() {
        //Code for the viewPager to change view
           System.out.println("The value of the time_tomove ");
           time_tomove++;
           Message msg = handler_timer.obtainMessage();
            Bundle b = new Bundle();
            b.putInt("time", time_tomove);
            msg.setData(b);
            handler_timer.sendMessage(msg);
      }
     }




public static Handler handler_timer = new Handler(){
    @Override
    public void handleMessage(Message msg) {
        super.handleMessage(msg);
    magazineHolder.setCurrentItem(time_tomove);
    }
};

完成此操作后，您可以在 onresume 或 oncreate() 方法中调用以下两行

timer = new Timer();
         timer.schedule(new UpdateTimeTask(), 100, 2000);
于 2014-01-29T13:36:22.860 回答
0

科特林方式

这是来自 Fragment 上下文，requireActivity()如果您在 Activity中，请删除

private var timer: Timer? = null
private var page = 0
private var maxPages = 4

   // Use this method to setup your viewpager in your onCreate() or onActivityCreated() methods
   fun setupViewPager(){
    viewPager2.adapter = MyAdapter()
    viewPager2.isUserInputEnabled = false
    pageSwitcher(5)
}

fun pageSwitcher(seconds: Int) {
    timer = Timer()
    timer!!.scheduleAtFixedRate(RemindTask(), 0, seconds * 1000.toLong())
}

class RemindTask:TimerTask(){

        override fun run() {
            requireActivity().runOnUiThread {
                if(page == maxPages){
                    page = 0
                }else{
                    viewPager2.setCurrentItem(page++,true)
                }
            }
        }
    }
于 2020-01-22T17:54:35.170 回答