21

我是一名 n00b 程序员，需要很多帮助。

仅出于教程目的，我想做简单的动植物（植物和动物）百科全书

我想让我的主屏幕像 Android 的主屏幕一样可拖动。向右滑动打开植物页面，向左滑动打开动物页面。我不知道如何制作过渡效果。所以我们可以把它拖到一半来查看下一页的内容，然后拖回来取消它

你们能分享一个链接来制作可拖动的屏幕吗？

之前谢谢

[编辑]

@Agarwal 我尝试了您 Link2 中的代码，但它不起作用

我尝试通过将 Toast 放在内部类中来测试是否检测到手势，但没有显示 Toast。Link1 基本相同。

从代码的外观来看，我认为它不能让我的屏幕像 Android 的主屏幕那样可拖动

我的代码：

public class Home extends Activity implements OnClickListener {
    private GestureDetector gestureDetector;
    View.OnTouchListener gestureListener;
    ImageButton flora, fauna;
    Intent go;

@Override
public void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.main);

    initialize();

    gestureDetector = new GestureDetector(new SwipeGestureDetector());
    gestureListener = new View.OnTouchListener() {
        public boolean onTouch(View v, MotionEvent event) {
            return gestureDetector.onTouchEvent(event);
        }
    };
}

private void initialize() {
    //find view by id to image button
    //set onClickListener to image button
}

public void onClick(View v) {
    //normal switch and case for each button

}

private void onLeftSwipe() {
    Toast t = Toast.makeText(Home.this, "Left swipe", Toast.LENGTH_LONG);
    t.show();
    go = new Intent("test.apps.FLORA");
    startActivity(go);
}

private void onRightSwipe() {
    Toast t = Toast.makeText(Home.this, "Right swipe", Toast.LENGTH_LONG);
    t.show();
    go = new Intent("test.apps.FAUNA");
    startActivity(go);
}

private class SwipeGestureDetector extends SimpleOnGestureListener {
    private static final int SWIPE_MIN_DISTANCE = 50;
    private static final int SWIPE_MAX_OFF_PATH = 200;
    private static final int SWIPE_THRESHOLD_VELOCITY = 200;

    @Override
    public boolean onFling(MotionEvent e1, MotionEvent e2, float velocityX,
            float velocityY) {
        try {
            Toast t = Toast.makeText(Home.this, "Gesture detected", Toast.LENGTH_SHORT);
            t.show();
            float diffAbs = Math.abs(e1.getY() - e2.getY());
            float diff = e1.getX() - e2.getX();

            if (diffAbs > SWIPE_MAX_OFF_PATH)
                return false;

            // Left swipe
            if (diff > SWIPE_MIN_DISTANCE
                    && Math.abs(velocityX) > SWIPE_THRESHOLD_VELOCITY) {
                Home.this.onLeftSwipe();
            } 
            // Right swipe
            else if (-diff > SWIPE_MIN_DISTANCE
                    && Math.abs(velocityX) > SWIPE_THRESHOLD_VELOCITY) {
                Home.this.onRightSwipe();
            }
        } catch (Exception e) {
            Log.e("Home", "Error on gestures");
        }
        return false;
    }

}
}
4

3 回答 3

16

我意识到这是一个老问题，但对于其他想知道为什么上面的代码不起作用的人来说，这是因为他没有将 OnTouchListener 设置为 View 对象。这就是为什么他的滑动“事件”没有被拾取，因为没有人在听它。

他可以添加这一行来在他的图像按钮上设置滑动（尽管你可能想要一个更好的 View 对象然后这个）：

flora.setOnTouchListener(gestureListener);
于 2012-10-23T15:44:44.440 回答
3

Android Activity 滑动检测

创建一个基础活动类

public abstract class _SwipeActivityClass extends AppCompatActivity
{
    private static final int SWIPE_MIN_DISTANCE = 120;
    private static final int SWIPE_MAX_OFF_PATH = 250;
    private static final int SWIPE_THRESHOLD_VELOCITY = 200;
    private GestureDetector gestureDetector;

    @Override
    protected void onCreate(Bundle savedInstanceState)
    {
        super.onCreate(savedInstanceState);
        gestureDetector = new GestureDetector( this, new SwipeDetector());
    }

    protected abstract void onSwipeRight();
    protected abstract void onSwipeLeft();

    public class SwipeDetector extends GestureDetector.SimpleOnGestureListener
    {
        @Override
        public boolean onFling(MotionEvent e1, MotionEvent e2, float velocityX, float velocityY)
        {

            // Check movement along the Y-axis. If it exceeds SWIPE_MAX_OFF_PATH,
            // then dismiss the swipe.
            if (Math.abs(e1.getY() - e2.getY()) > SWIPE_MAX_OFF_PATH)
            {
                return false;
            }

            //toast( "start = "+String.valueOf( e1.getX() )+" | end = "+String.valueOf( e2.getX() )  );
            //from left to right
            if( e2.getX() > e1.getX() )
            {
                if (e2.getX() - e1.getX() > SWIPE_MIN_DISTANCE && Math.abs(velocityX) > SWIPE_THRESHOLD_VELOCITY)
                {
                    onSwipeRight();
                    return true;
                }
            }

            if( e1.getX() > e2.getX() )
            {
                if (e1.getX() - e2.getX() > SWIPE_MIN_DISTANCE && Math.abs(velocityX) > SWIPE_THRESHOLD_VELOCITY)
                {
                    onSwipeLeft();
                    return true;
                }
            }

            return false;
        }
    }

    @Override
    public boolean dispatchTouchEvent(MotionEvent ev)
    {
        // TouchEvent dispatcher.
        if (gestureDetector != null)
        {
            if (gestureDetector.onTouchEvent(ev))
            // If the gestureDetector handles the event, a swipe has been
            // executed and no more needs to be done.
            return true;
        }

        return super.dispatchTouchEvent(ev);
    }

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

然后从_SwipeActivityClass扩展您的活动

实现方法onSwipeLeft()和onSwipeRight()来启动另一个活动

于 2017-06-09T13:05:32.397 回答