最佳答案
ACTION_UP 未调用
考虑下面的方案(为了更好地理解我的问题)。
如您所见，我正在考虑一个由填充包围的列表视图。现在，如果用户按下一个列表视图项，作为动作，我已经提供了它浅蓝色的背景颜色。现在，我的应用程序正在处理 onTouch 事件本身，以确定如下操作
- 咔嚓
- 从左到右滑动
- 从右向左滑动
这是我的密码。
public boolean onTouch(View v, MotionEvent event) {
if(v == null)
{
mSwipeDetected = Action.None;
return false;
}
switch (event.getActionMasked()) {
case MotionEvent.ACTION_DOWN: {
downX = event.getRawX();
downY = event.getRawY();
mSwipeDetected = Action.Start;
// Find the child view that was touched (perform a hit test)
Rect rect = new Rect();
int childCount = listView.getChildCount();
int[] listViewCoords = new int[2];
listView.getLocationOnScreen(listViewCoords);
int x = (int) event.getRawX() - listViewCoords[0];
int y = (int) event.getRawY() - listViewCoords[1];
View child;
for (int i = 0; i < childCount; i++) {
child = listView.getChildAt(i);
child.getHitRect(rect);
if (rect.contains(x, y)) {
mDownView = child;
break;
}
}
return false; // allow other events like Click to be processed
}
case MotionEvent.ACTION_MOVE: {
upX = event.getRawX();
upY = event.getRawY();
float deltaX=0,deltaY=0;
deltaX = downX - upX;
deltaY = downY - upY;
if(deltaY < VERTICAL_MIN_DISTANCE)
{
setTranslationX(mDownView, -(deltaX));
setAlpha(mDownView, Math.max(0f, Math.min(1f, 1f - 2f * Math.abs(deltaX) / listView.getWidth())));
return false;
}
else
{
forceBringBack(v);
}
return false;
}
case MotionEvent.ACTION_UP:
{
stopX = event.getX();
float stopValueY = event.getRawY() - downY;
float stopValue = stopX - downX;
if(!mDownView.isPressed())
{
forceBringBack(mDownView);
return false;
}
boolean dismiss = false;
boolean dismissRight = false;
if(Math.abs(stopValue)<10)
{
mSwipeDetected = Action.Start;
}
else
{
mSwipeDetected = Action.None;
}
String log = "";
Log.d(log, "Here is Y" + Math.abs(stopValueY));
Log.d(log, "First Comparison of Stop Value > with/4" + (Math.abs(stopValue) > (listView.getWidth() /4)));
Log.d(log, "Second Comparison " + (Math.abs(stopValueY)<VERTICAL_MIN_DISTANCE));
Log.d(log, "Action Detected is " + mSwipeDetected + " with Stop Value " + stopValue);
if((Math.abs(stopValue) > (listView.getWidth() /4))&&(Math.abs(stopValueY)<VERTICAL_MIN_DISTANCE))
{
dismiss = true;
dismissRight = stopValue > 0;
if(stopValue>0)
{
mSwipeDetected = Action.LR;
}
else
mSwipeDetected = Action.RL;
}
Log.d(log, "Action Detected is " + mSwipeDetected + " with Stop Value after dissmiss" + stopValue);
if(dismiss)
{
if(dismissRight)
mSwipeDetected = Action.LR;
else
mSwipeDetected = Action.RL;
animate(mDownView)
.translationX(dismissRight ? listView.getWidth() : - listView.getWidth())
.alpha(0)
.setDuration(mAnimationTime)
.setListener(new AnimatorListenerAdapter() {
public void onAnimationEnd(Animator animation)
{
}
});
}
else
{
animate(mDownView)
.translationX(0)
.alpha(1)
.setDuration(mAnimationTime)
.setListener(null);
}
break;
}
}
return false;
}
如您所见，我确定了 MotionEvent.ACTION _ UP 中执行的操作，并相应地设置了 Enum Action 的值。如果用户没有越过列表视图边界，那么这种逻辑就非常有用。
现在，如果用户在滑动(或者特别地)时，将手指沿着列表项从蓝色移动到橙色，MotionEvent.ACTION _ UP 将不会被赋予 listview，这会导致我的代码无法做出决定，并且由于 transationX ()方法和 setAlpha () ，因为在这种情况下没有确定任何操作，所以特定的列表项将变为空白。
问题并没有到此为止，因为我没有每次都充满视图，相同的 translatedX ()行每次都会充满，导致多次出现空白/白色列表项。
有没有什么可能做到这一点，即使我没有遇到 MotionEvent.ACTION _ UP，我仍然可以做出一些决定？
