Question

我使用ViewPager和滑动选项如何检测滑动开始（视图开始之间转换的时刻）和滑动结束（视图停止时的转换时刻）？

Answer 1

您可以创建自己的自定义视图寻呼机并覆盖onDrag或onTouch事件方法。

public class MyViewPager extends ViewPager{

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

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

public MyViewPager(Context context, AttributeSet attrs, int defStyleAttr) {
    super(context, attrs, defStyleAttr);
}

@Override
public boolean onDragEvent(DragEvent event) {
    return super.onDragEvent(event);
}

@Override
public boolean onTouchEvent(MotionEvent event) {
    return super.onTouchEvent(event);
}
}

Answer 2

您可以使用OnPageChangeListener。方法onPageScrolled (int position, float positionOffset, int positionOffsetPixels)将通知您页面更改的进度（以像素为单位，或者作为0到1之间的浮点数），因此很容易看到它何时开始和停止。继承人的文件： http://developer.android.com/reference/android/support/v4/view/ViewPager.OnPageChangeListener.html#onPageScrolled%28int,%20float,%20int%29

Answer 3

您可以实现ViewPager类的OnPageListener接口。该界面提供了三种方法来监听ViewPager的更改。

 @Override
  public void onPageScrollStateChanged(int state) {
   //Called when the scroll state changes.
   // The state variable that you receive as parameter will help you know the state of the view pager. 
   // The ViewPager can be in any of the three states, 
   // SCROLL_STATE_IDLE, SCROLL_STATE_DRAGGING, SCROLL_STATE_SETTLING
   // If the state is SCROLL_STATE_DRAGGING, it signals that the page is being dragged. A transition to this state can signal a start of drag.
   // If the state is SCROLL_STATE_IDLE, it signals that there is no dragging going on and a possible end of any drags.
   // Keep a variable that changes state as per your requirements.
  }

  @Override
  public void onPageScrolled(int position, 
    float positionOffset, int positionOffsetPixels) {
   //This method will be invoked when the current page is scrolled, 
   //either as part of a programmatically initiated smooth scroll 
   //or a user initiated touch scroll.
   // The positionOffset parameted returns a float between [0,1) Any number between 0 and 1 indicates that the page is being dragged. 
   // This can be used as an indicator for drag start and end events.
  }

  @Override
  public void onPageSelected(int position) {
   //This method will be invoked when a new page becomes selected.

  }};

一切顺利：）

Android ViewPager开始滑动并停止滑动

3 个答案: