Question

我在布局中使用了scrollview。我需要在有滚动事件时设置动画，并在滚动结束时停止动画。

我检查了scrollview但它似乎没有提供这些事件。我需要使用手势检测器吗？

请帮忙。

谢谢，斯纳

Answer 1

import android.view.GestureDetector;
import android.view.GestureDetector.SimpleOnGestureListener;
import android.view.MotionEvent;
import android.view.View;
import android.view.View.OnTouchListener;

public class OnSwipeTouchListener implements OnTouchListener {

    private final GestureDetector gestureDetector;

    public OnSwipeTouchListener (Context ctx){
        gestureDetector = new GestureDetector(ctx, new GestureListener());
    }

    private final class GestureListener extends SimpleOnGestureListener {

        private static final int SWIPE_THRESHOLD = 100;
        private static final int SWIPE_VELOCITY_THRESHOLD = 100;

        @Override
        public boolean onDown(MotionEvent e) {
            return true;
        }

        @Override
        public boolean onFling(MotionEvent e1, MotionEvent e2, float velocityX, float velocityY) {
            boolean result = false;
            try {
                float diffY = e2.getY() - e1.getY();
                float diffX = e2.getX() - e1.getX();
                if (Math.abs(diffX) > Math.abs(diffY)) {
                    if (Math.abs(diffX) > SWIPE_THRESHOLD && Math.abs(velocityX) > SWIPE_VELOCITY_THRESHOLD) {
                        if (diffX > 0) {
                            onSwipeRight();
                        } else {
                            onSwipeLeft();
                        }
                    }
                    result = true;
                } 
                else if (Math.abs(diffY) > SWIPE_THRESHOLD && Math.abs(velocityY) > SWIPE_VELOCITY_THRESHOLD) {
                        if (diffY > 0) {
                            onSwipeBottom();
                        } else {
                            onSwipeTop();
                        }
                    }
                    result = true;

            } catch (Exception exception) {
                exception.printStackTrace();
            }
            return result;
        }
    }

    public void onSwipeRight() {
    }

    public void onSwipeLeft() {
    }

    public void onSwipeTop() {
    }

    public void onSwipeBottom() {
    }
}

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Answer 2

您可以展开ScrollView，并覆盖

@Override
protected void onScrollChanged(int l, int t, int oldl, int oldt)

获取滚动条。要在您的activity / fragment中获取此值，您还可以定义一个侦听器

Answer 3

这解决了我的问题！：）

svMovieDetails.setOnTouchListener（new View.OnTouchListener（）{

        @Override
        public boolean onTouch( View v, MotionEvent event ) {
            switch ( event.getAction( ) ) {
                case MotionEvent.ACTION_SCROLL:
                case MotionEvent.ACTION_MOVE:
                    Log.e( "SCROLL", "ACTION_SCROLL" );
                    break;
                case MotionEvent.ACTION_DOWN:
                    Log.e( "SCROLL", "ACTION_DOWN" );
                    break;
                case MotionEvent.ACTION_CANCEL:
                case MotionEvent.ACTION_UP:
                    Log.e( "SCROLL", "SCROLL_STOP" );
                    break;
            }
            return false;
        }
    } );

无论如何我能检测到滚动和滚动停止事件吗？

3 个答案: