[英]Android: How do I place a ScrollView (with text in) into Gallery?
我將在Android應用程序中的文本中放置文本。 該文本位於scrollView中。 一切正常但是在向右或向左拖動文本時,沒有下一頁/元素顯示(屏幕保持靜止)。如果我在scrollView之外有一些東西,它會在拖動時更改為下一個元素。
有人可以幫忙嗎?
你需要重寫onInterceptTouchEvent
-你可以用它來獲得MotionEvent
就是他們交付給前ScrollView
,然后將其重定向到您ViewGroup
( Gallery
如果你想在這種情況下)。
如果用戶將手指向左或向右移動太遠,則以下類將MotionEvent
重定向到您的Gallery
。 此外,如果用戶向上或向下移動手指相當一點,那么向左或向右移動手指將不再具有效果,因此您不必擔心在進行大量滾動時圖庫會發生變化。
class ScrollViewGallery extends Gallery {
/**
* The distance the user has to move their finger, in density independent
* pixels, before we count the motion as A) intended for the ScrollView if
* the motion is in the vertical direction or B) intended for ourselfs, if
* the motion is in the horizontal direction - after the user has moved this
* amount they are "locked" into this direction until the next ACTION_DOWN
* event
*/
private static final int DRAG_BOUNDS_IN_DP = 20;
/**
* A value representing the "unlocked" state - we test all MotionEvents
* when in this state to see whether a lock should be make
*/
private static final int SCROLL_LOCK_NONE = 0;
/**
* A value representing a lock in the vertical direction - once in this state
* we will never redirect MotionEvents from the ScrollView to ourself
*/
private static final int SCROLL_LOCK_VERTICAL = 1;
/**
* A value representing a lock in the horizontal direction - once in this
* state we will not deliver any more MotionEvents to the ScrollView, and
* will deliver them to ourselves instead.
*/
private static final int SCROLL_LOCK_HORIZONTAL = 2;
/**
* The drag bounds in density independent pixels converted to actual pixels
*/
private int mDragBoundsInPx = 0;
/**
* The coordinates of the intercepted ACTION_DOWN event
*/
private float mTouchStartX;
private float mTouchStartY;
/**
* The current scroll lock state
*/
private int mScrollLock = SCROLL_LOCK_NONE;
public ScrollViewGallery(Context context) {
super(context);
initCustomGallery(context);
}
public ScrollViewGallery(Context context, AttributeSet attrs) {
super(context, attrs);
initCustomGallery(context);
}
public ScrollViewGallery(Context context, AttributeSet attrs,
int defStyle) {
super(context, attrs, defStyle);
initCustomGallery(context);
}
private void initCustomGallery(Context context) {
final float scale = context.getResources().getDisplayMetrics().density;
mDragBoundsInPx = (int) (scale*DRAG_BOUNDS_IN_DP + 0.5f);
}
/**
* This will be called before the intercepted views onTouchEvent is called
* Return false to keep intercepting and passing the event on to the target view
* Return true and the target view will recieve ACTION_CANCEL, and the rest of the
* events will be delivered to our onTouchEvent
*/
@Override
public boolean onInterceptTouchEvent(MotionEvent ev) {
final int action = ev.getAction();
switch (action) {
case MotionEvent.ACTION_DOWN:
mTouchStartX = ev.getX();
mTouchStartY = ev.getY();
mScrollLock = SCROLL_LOCK_NONE;
/**
* Deliver the down event to the Gallery to avoid jerky scrolling
* if we decide to redirect the ScrollView events to ourself
*/
super.onTouchEvent(ev);
break;
case MotionEvent.ACTION_MOVE:
if (mScrollLock == SCROLL_LOCK_VERTICAL) {
// keep returning false to pass the events
// onto the ScrollView
return false;
}
final float touchDistanceX = (ev.getX() - mTouchStartX);
final float touchDistanceY = (ev.getY() - mTouchStartY);
if (Math.abs(touchDistanceY) > mDragBoundsInPx) {
mScrollLock = SCROLL_LOCK_VERTICAL;
return false;
}
if (Math.abs(touchDistanceX) > mDragBoundsInPx) {
mScrollLock = SCROLL_LOCK_HORIZONTAL; // gallery action
return true; // redirect MotionEvents to ourself
}
break;
case MotionEvent.ACTION_CANCEL:
case MotionEvent.ACTION_UP:
// if we're still intercepting at this stage, make sure the gallery
// also recieves the up/cancel event as we gave it the down event earlier
super.onTouchEvent(ev);
break;
}
return false;
}
}
我理解你的問題。 在重寫方法之后,我已經處理了這種情況。 我不確定這將是最好的解決方案,可能有一個人有更有效的解決方案然后這個,但它適用於我。
我用過度騎行的方法使用了畫廊的自定義對象。
public boolean isScrollingLeft(MotionEvent e1, MotionEvent e2) {
return e2.getX() > e1.getX();
}
@Override
public boolean onFling(MotionEvent e1, MotionEvent e2, float velocityX,
float velocityY) {
return super.onFling(e1, e2, 0, velocityY);
}
我發現如果你將文本視圖放在垂直滾動條模式下,它只會向上或向下移動。 如果我們想要水平滑動,您必須觸摸textview之外。
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