如何在視圖傳呼機中自動更改圖像，當它到達最後一張圖像時它應該自動到達第一張圖像

Question

我現在正在實現視圖傳呼機，並且我想要在特定的時期自動地逐一更改圖像時間可能在5毫秒內一次。

我也有手動允許用戶刷卡圖像（它工作正常）

但圖像不會自動改變，當它到達最後的圖像就會自動走到第一圖像

final Handler handler = new Handler(); 
     final Runnable Update = new Runnable() { 
      public void run() { 
       if (currentPage == strImages.length-1) { 
        currentPage = 0; 
       } 
       intro_images.setCurrentItem(currentPage++, true); 
      } 
     }; 

     timer = new Timer(); // This will create a new Thread 
     timer .schedule(new TimerTask() { // task to be scheduled 

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

我用上面的代碼，但它不能正常工作

Answer 1

嘗試這種添加addOnPageChangeListener您viewPager這樣

 viewPager.addOnPageChangeListener(new ViewPager.OnPageChangeListener() { 
     @Override 
     public void onPageScrolled(int position, float positionOffset, int positionOffsetPixels) { 
      if (position == strImages.length-1) { 
       currentPage = 0; 
      } 
      intro_images.setCurrentItem(currentPage++, true); 
     } 

     @Override 
     public void onPageSelected(int position) { 

     } 

     @Override 
     public void onPageScrollStateChanged(int state) { 

     } 
    }); 

或自動切換頁面試試這個創建這樣

Timer timer; 
timer = new Timer(); 
timer.scheduleAtFixedRate(new RemindTask(), 0, 3000); // delay*/ 

private class RemindTask extends TimerTask { 
int current = viewPager.getCurrentItem(); 

@Override 
public void run() { 
    runOnUiThread(new Runnable() { 
     public void run() { 

      if (current < strImages.size()) { 
        viewPager.setCurrentItem(current); 
        current += 1; 
       } else { 

        current = 0; 
        viewPager.setCurrentItem(current); 

       } 
     } 
    }); 

} 
} 

Answer 2

AnimationDrawable animation = new AnimationDrawable(); 

Answer 3

一次任務只需添加監聽到你的viewpager得到最後的位置，並滾動到第一位置。

vp.addOnPageChangeListener(new ViewPager.OnPageChangeListener() { 
        @Override 
        public void onPageSelected(int position) { 
         if(position==yourlist.length){ 
          vp.setCurrentItem(0); 
         } 
        } 
       }); 

Answer 4

下面的代碼是獲得最後的位置，並滾動到1號位：

pager.addOnPageChangeListener(new ViewPager.OnPageChangeListener() 
{ 
      @Override 

     public void onPageScrolled(int position, float positionOffset,int positionOffsetPixels) { 
       if (position == Yourlist.size()-1) { 
        pager.setCurrentItem(0); 
       } 
        pager.setCurrentItem(position++,true); 


      } 

      @Override 
      public void onPageSelected(int position) { 

      } 

      @Override 
      public void onPageScrollStateChanged(int state) { 

      } 
     }); 

下面的代碼是爲了在使用倒數計時器每10秒自動改變畫面：

- First you have to declare one array,which will contain your 
    images,then after you have to use below code. 

int i=0; 


new CountDownTimer(1000,1000) 
{ 

       @Override 
       public void onTick(long millisUntilFinished) {} 

       @Override 
       public void onFinish() { 
        iV.setImageDrawable(sdk.getContext().getResources().getDrawable(array[i])); 
        i++; 
        if(i== array.length-1) {i=0;} 
        start(); 
       } 
      }.start(); 

Answer 5

您不需要Handler和的組合對於這一點，你可以用簡單的Handler這樣使用Handler.postDelayed

private Handler handler = new Handler(); 

final Runnable Update = new Runnable() { 
    public void run() { 
     int totalCount = intro_images.getAdapter().getCount(); 
     int currentItem = intro_images.getCurrentItem(); 
     if (currentItem == (totalCount - 1)) { 
      currentItem = 0; 
     } else { 
      currentItem = currentItem + 1; 
     } 
     intro_images.setCurrentItem(currentItem, true); 

     handler.postDelayed(this, 3000); 
    } 
}; 

@Override 
protected void onResume() { 
    super.onResume(); 

    handler.postDelayed(Update, 500); 
} 

@Override 
protected void onPause() { 
    super.onPause(); 

    if(handler != null) { 
     handler.removeCallbacks(Update); 
    } 
}