Question

我想在我的应用程序中左右滑动，但是当我使用PhotoView库时，不会触发Swipe事件。

如何使用PhotoView库实现滑动操作？

OnSwipeTouchListener.java

import android.content.Context;
import android.view.GestureDetector;
import android.view.MotionEvent;
import android.view.View;

public class OnSwipeTouchListener implements View.OnTouchListener {

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

    public boolean onTouch(final View view, final MotionEvent motionEvent) {
        return gestureDetector.onTouchEvent(motionEvent);
    }

    private final class GestureListener extends GestureDetector.SimpleOnGestureListener {

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

        @Override
        public boolean onDown(MotionEvent e) {
            return true;
        }
        // Determines the fling velocity and then fires the appropriate swipe event accordingly
        @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();
                        }
                    }
                } else {
                    if (Math.abs(diffY) > SWIPE_THRESHOLD && Math.abs(velocityY) > SWIPE_VELOCITY_THRESHOLD) {
                        if (diffY > 0) {
                            onSwipeDown();
                        } else {
                            onSwipeUp();
                        }
                    }
                }
            } catch (Exception exception) {
                exception.printStackTrace();
            }
            return result;
        }
    }
    public void onSwipeRight() {
    }

    public void onSwipeLeft() {
    }

    public void onSwipeUp() {
    }

    public void onSwipeDown() {
    }
}

My MainActivity我使用SwipeEvent和PhotoView

@Override
protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.activity_main);

    // Setup Universial Image Loader
    DisplayImageOptions defaultOptions = new DisplayImageOptions.Builder()
            .cacheInMemory(true)
            .cacheOnDisc(true)
            .build();

    ImageLoaderConfiguration config = new ImageLoaderConfiguration.Builder(getApplicationContext())
            .defaultDisplayImageOptions(defaultOptions)
            .build();
    ImageLoader.getInstance().init(config);


    imageViewComic = (ImageView) findViewById(R.id.imageViewComic);

    imageViewComic.setOnTouchListener(new OnSwipeTouchListener(this) {
        @Override
        public void onSwipeDown() {
            Toast.makeText(MainActivity.this, "Down", Toast.LENGTH_SHORT).show();
        }

        @Override
        public void onSwipeLeft() {
            Toast.makeText(MainActivity.this, "Left", Toast.LENGTH_SHORT).show();
        }

        @Override
        public void onSwipeUp() {
            Toast.makeText(MainActivity.this, "Up", Toast.LENGTH_SHORT).show();
        }

        @Override
        public void onSwipeRight() {
            Toast.makeText(MainActivity.this, "Right", Toast.LENGTH_SHORT).show();
        }
    });

    mAttacher = new PhotoViewAttacher(imageViewComic);


    // Button for loading latest comic
    btnLatestComic = (Button) findViewById(R.id.btnLoadComic);
    btnLatestComic.setOnClickListener(new View.OnClickListener() {
        @Override
        public void onClick(View view) {
            new JSONParse().execute("http://xkcd.com/info.0.json");
        }
    });


    // Button for loading previous comic
    btnPrevComic = (Button) findViewById(R.id.btnPrevComic);
    btnPrevComic.setOnClickListener(new View.OnClickListener() {
        @Override
        public void onClick(View view) {
           getPrevComic();
        }
    });


    // Button for loading next comic
    btnNextComic = (Button) findViewById(R.id.btnNextComic);
    btnNextComic.setOnClickListener(new View.OnClickListener() {
        @Override
        public void onClick(View view) {
            getNextComic();
        }
    });





    SharedPreferences Sharedsettings;
    SharedPreferences.Editor editor;
    Sharedsettings = PreferenceManager.getDefaultSharedPreferences(getApplicationContext());
    boolean load_latest = Sharedsettings.getBoolean("load_latest_startup", true);

    if( load_latest == true) {
        //Load latest comic
        new JSONParse().execute("http://xkcd.com/info.0.json");
    }
    else
    {
        getLastComic();
    }


}

Answer 1

使用此类创建fling函数，它将简单地扩展SimpleOnGestureListener，然后使用该fling函数来滑动图像。我在这里使用ViewPager。

class MyGestureDetector extends SimpleOnGestureListener {
    @Override
    public boolean onFling(MotionEvent e1, MotionEvent e2, float velocityX, float velocityY) {
        try {
            if (Math.abs(e1.getY() - e2.getY()) > SWIPE_MAX_OFF_PATH)
                return false;
            // right to left swipe
            if (e1.getX() - e2.getX() > SWIPE_MIN_DISTANCE  && Math.abs(velocityX) > SWIPE_THRESHOLD_VELOCITY
                    && selectedPg == (pageCount - 1)) {
                shop_view_pager.setCurrentItem(0);
                return true;
            } else if (e2.getX() - e1.getX() > SWIPE_MIN_DISTANCE   && Math.abs(velocityX) > SWIPE_THRESHOLD_VELOCITY
                    && selectedPg == 0) {
                shop_view_pager.setCurrentItem(pageCount - 1);
                return true;
            }
        } catch (Exception e) {
            // nothing
        }
        return false;
    }
}

现在为MyGestureDetector创建一个对象，并使用OnTouchListener设置手势功能。

final GestureDetector gestureDetector = new GestureDetector(new MyGestureDetector());
    view_pager.setOnTouchListener(new OnTouchListener() {
        public boolean onTouch(View v, MotionEvent event) {
            return gestureDetector.onTouchEvent(event);
        }
    });
    view_pager.setOnPageChangeListener(new OnPageChangeListener() {

        public void onPageSelected(int position) {
            selectedPg = position;
        }

使用PhotoView库时未触发滑动事件

1 个答案: