Android ViewPager 自动换页 [英] Android ViewPager automatically change page

问题描述

我想安排一个动作来自动更改我的 ViewPager 页面.我试过了:

I want to schedule an action to change automatically my ViewPager pages. I've tried:

@Override
    public void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);

    ...

    swipeTimer = new Timer();
    swipeTimer.schedule(new TimerTask() {

         @Override
         public void run() {
            if (currentPage == NUM_PAGES) {
                currentPage = 0;
            }
            featureViewPager.setCurrentItem(currentPage++, true);
         }
    }, 100, 500);

但我总是得到:

E/AndroidRuntime(5381): FATAL EXCEPTION: Timer-0
E/AndroidRuntime(5381): java.lang.IllegalStateException: Must be called from main thread of process

我已经在主线程中了，对吧?我该如何解决?
感谢您抽出宝贵时间.

I'm already in main thread right? How can I solve this?
Thanks for your time.

====================================

感谢您的所有回答.根据这些回复，我发现了 2 个解决方案:
解决方案 1:

====================================

Thanks for all your answers. Based on these responses I came across 2 solutions:
Solution 1:

swipeTimer = new Timer();
            swipeTimer.schedule(new TimerTask() {

                @Override
                public void run() {
                    runOnUiThread(new Runnable() {
                        @Override
                        public void run() {
                            if (currentPage == NUM_PAGES) {
                                currentPage = 0;
                            }
                            featureViewPager.setCurrentItem(currentPage++, true);
                        }
                    });
                }
            }, 500, 3000);

解决方案 2:

Solution 2:

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

            swipeTimer = new Timer();
            swipeTimer.schedule(new TimerTask() {

                @Override
                public void run() {
                    handler.post(Update);
                }
            }, 500, 3000);

哪个更好或它们相同?
再次感谢.

Which one is better or they are the same?
Thanks once again.

推荐答案

如果你想在主 UI 中使用线程，那么你需要使用一个hander来处理它.

If you want to use thread in the main UI then you need to use a hander to hand it.

Handler handler = new Handler();

        Runnable update = new Runnable()  {

            public void run() {
                if ( currentPage == NUM_PAGES ) {

                    currentPage = 0;
                }
                featureViewPager.setCurrentItem(currentPage++, true);
            }
        };


        new Timer().schedule(new TimerTask() {

            @Override
            public void run() {
                handler.post(update);
            }
        }, 100, 500);

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