Android 如何平滑列表项在特定位置的移动
我有listView。当物品处于特定位置时,他会改变颜色。看图片。上面有蓝色的方块-这就是我现在拥有的。向下-我需要的。但是当滚动时,当项目处于所需位置并改变颜色时,它不会顺利发生。该项目似乎跳转到所需的位置。我怎样才能使这个过程更顺利?谢谢 以下是我的视图类的一部分:Android 如何平滑列表项在特定位置的移动,android,scroll,android-listview,smooth-scrolling,Android,Scroll,Android Listview,Smooth Scrolling,我有listView。当物品处于特定位置时,他会改变颜色。看图片。上面有蓝色的方块-这就是我现在拥有的。向下-我需要的。但是当滚动时,当项目处于所需位置并改变颜色时,它不会顺利发生。该项目似乎跳转到所需的位置。我怎样才能使这个过程更顺利?谢谢 以下是我的视图类的一部分: public class TimeView extends View { ........................... @Override public void setOnScrollChangeL
public class TimeView extends View {
...........................
@Override
public void setOnScrollChangeListener(OnScrollChangeListener l) {
}
AbsListView.OnScrollListener scrollListener = new AbsListView.OnScrollListener() {
@Override
public void onScrollStateChanged(final AbsListView view, int scrollState) {
if (scrollState == SCROLL_STATE_IDLE) {
View childView = view.getChildAt(0);
int position = view.getFirstVisiblePosition();
if (-childView.getTop() > childView.getHeight() / 2) {
position++;
}
view.setSelection(position);
}
}
@Override
public void onScroll(final AbsListView view, int firstVisibleItem, int visibleItemCount, int totalItemCount) {
for (int i = 0; i < view.getChildCount(); i++) {
View childView = view.getChildAt(i);
if (i == 1) {
childView.setBackgroundResource(R.drawable.selected_color);
} else {
childView.setBackgroundResource(R.drawable.no_select_color);
}
}
}
};
如果切换到使用RecyclerView而不是ListView(无论如何都应该使用ListView),则可以使用SnapHelper执行以下操作:
SnapHelper helper = new LinearSnapHelper();
helper.attachToRecyclerView(recyclerView);
如果切换到使用RecyclerView而不是ListView(无论如何都应该使用ListView),则可以使用SnapHelper执行以下操作:
SnapHelper helper = new LinearSnapHelper();
helper.attachToRecyclerView(recyclerView);
试试这个:
@Override
public void onScrollStateChanged(final AbsListView view, int scrollState) {
if (scrollState == SCROLL_STATE_IDLE) {
View firstView = view.getChildAt(0);
Rect rect = new Rect(0, 0, firstView.getWidth(), firstView.getHeight());
view.getChildVisibleRect(firstView, rect, null);
int position = view.getFirstVisiblePosition();
if (rect.height() < (firstView.getHeight() / 2)) {
position++;
}
final int finalPosition = position;
view.postDelayed(new Runnable() {
@Override
public void run() {
view.smoothScrollToPositionFromTop(finalPosition, 0, 500);
}
}, 1);
}
}
更新:
上述代码具有500毫秒的恒定稳定时间。下面的代码具有恒定的捕捉速度0.2像素/毫秒,这意味着向上/向下滚动一个像素需要5毫秒
final static int SCROLL_TIME_PER_PIXEL = 5; // Time(ms) to snap a pixel.
@Override
public void onScrollStateChanged(final AbsListView view, int scrollState) {
if (scrollState == SCROLL_STATE_IDLE) {
View firstView = view.getChildAt(0);
Rect rect = new Rect(0, 0, firstView.getWidth(), firstView.getHeight());
view.getChildVisibleRect(firstView, rect, null);
int position = view.getFirstVisiblePosition();
int offset = rect.height();
if (rect.height() < (firstView.getHeight() / 2)) {
position++;
} else offset = firstView.getHeight() - rect.height();
final int finalPosition = position; // Snap to position.
final int finalOffset = offset; // Snap distance in pixels.
view.postDelayed(new Runnable() {
@Override
public void run() {
view.smoothScrollToPositionFromTop(finalPosition, 0, finalOffset * SCROLL_TIME_PER_PIXEL);
}
}, 1);
}
}
试试这个:
@Override
public void onScrollStateChanged(final AbsListView view, int scrollState) {
if (scrollState == SCROLL_STATE_IDLE) {
View firstView = view.getChildAt(0);
Rect rect = new Rect(0, 0, firstView.getWidth(), firstView.getHeight());
view.getChildVisibleRect(firstView, rect, null);
int position = view.getFirstVisiblePosition();
if (rect.height() < (firstView.getHeight() / 2)) {
position++;
}
final int finalPosition = position;
view.postDelayed(new Runnable() {
@Override
public void run() {
view.smoothScrollToPositionFromTop(finalPosition, 0, 500);
}
}, 1);
}
}
更新:
上述代码具有500毫秒的恒定稳定时间。下面的代码具有恒定的捕捉速度0.2像素/毫秒,这意味着向上/向下滚动一个像素需要5毫秒
final static int SCROLL_TIME_PER_PIXEL = 5; // Time(ms) to snap a pixel.
@Override
public void onScrollStateChanged(final AbsListView view, int scrollState) {
if (scrollState == SCROLL_STATE_IDLE) {
View firstView = view.getChildAt(0);
Rect rect = new Rect(0, 0, firstView.getWidth(), firstView.getHeight());
view.getChildVisibleRect(firstView, rect, null);
int position = view.getFirstVisiblePosition();
int offset = rect.height();
if (rect.height() < (firstView.getHeight() / 2)) {
position++;
} else offset = firstView.getHeight() - rect.height();
final int finalPosition = position; // Snap to position.
final int finalOffset = offset; // Snap distance in pixels.
view.postDelayed(new Runnable() {
@Override
public void run() {
view.smoothScrollToPositionFromTop(finalPosition, 0, finalOffset * SCROLL_TIME_PER_PIXEL);
}
}, 1);
}
}
加文·赖特,谢谢你的建议。但我必须用ListViewGavin Wright来做,谢谢你的建议。但是我必须使用ListViewi___________________________________?谢谢。谢谢。我会尝试报告结果。我尝试过使用你的建议,但似乎效果不错。非常感谢你!我是阿莫,你能解释一下这个方法是怎么起作用的吗?谢谢。谢谢。我会尝试报告结果。我尝试过使用你的建议,但似乎效果不错。非常感谢你!