Android 滚动后NotifyDataSetChanged不工作
我在ScrollView中实现了HorizontalListView()。 HorizontalListView不支持Android 滚动后NotifyDataSetChanged不工作,android,android-layout,android-linearlayout,horizontallist,notifydatasetchanged,Android,Android Layout,Android Linearlayout,Horizontallist,Notifydatasetchanged,我在ScrollView中实现了HorizontalListView()。 HorizontalListView不支持madapter.notifyDataSetChanged(),但当我水平滚动然后单击按钮调用下一个数据项时,它们不会显示。它们被追加到其余行中(因为它只有一个DataSetObserver) 即使在滚动后,如何在一行中显示附加项 或者如何刷新布局-我已经尝试了invalidate()和requestlayout() 这是我的HorizontalListView类的代码 publ
madapter.notifyDataSetChanged()代码>,但当我水平滚动然后单击按钮调用下一个数据项时,它们不会显示。它们被追加到其余行中(因为它只有一个DataSetObserver
)
即使在滚动后,如何在一行中显示附加项
或者如何刷新布局-我已经尝试了invalidate()
和requestlayout()
这是我的HorizontalListView
类的代码
public class HorizontalListView extends AdapterView<ListAdapter> {
public boolean mAlwaysOverrideTouch = true;
protected ListAdapter mAdapter;
private int mLeftViewIndex = -1;
private int mRightViewIndex = 0;
protected int mCurrentX;
protected int mNextX;
private int mMaxX = Integer.MAX_VALUE;
private int mDisplayOffset = 0;
protected Scroller mScroller;
private GestureDetector mGesture;
private Queue<View> mRemovedViewQueue = new LinkedList<View>();
private OnItemSelectedListener mOnItemSelected;
private OnItemClickListener mOnItemClicked;
private OnItemLongClickListener mOnItemLongClicked;
private boolean mDataChanged = false;
public HorizontalListView(Context context, AttributeSet attrs) {
super(context, attrs);
initView();
}
private synchronized void initView() {
mLeftViewIndex = -1;
mRightViewIndex = 0;
mDisplayOffset = 0;
mCurrentX = 0;
mNextX = 0;
mMaxX = Integer.MAX_VALUE;
mScroller = new Scroller(getContext());
mGesture = new GestureDetector(getContext(), mOnGesture);
}
@Override
public void setOnItemSelectedListener(AdapterView.OnItemSelectedListener listener) {
mOnItemSelected = listener;
}
@Override
public void setOnItemClickListener(AdapterView.OnItemClickListener listener){
mOnItemClicked = listener;
}
@Override
public void setOnItemLongClickListener(AdapterView.OnItemLongClickListener listener) {
mOnItemLongClicked = listener;
}
private DataSetObserver mDataObserver = new DataSetObserver() {
@Override
public void onChanged() {
synchronized(HorizontalListView.this){
mDataChanged = true;
}
invalidate();
// initView();
requestLayout();
}
@Override
public void onInvalidated() {
reset();
invalidate();
requestLayout();
}
};
@Override
public ListAdapter getAdapter() {
return mAdapter;
}
@Override
public View getSelectedView() {
//TODO: implement
return null;
}
@Override
public void setAdapter(ListAdapter adapter) {
if(mAdapter != null) {
mAdapter.unregisterDataSetObserver(mDataObserver);
}
mAdapter = adapter;
mAdapter.registerDataSetObserver(mDataObserver);
reset();
}
private synchronized void reset(){
initView();
removeAllViewsInLayout();
requestLayout();
}
@Override
public void setSelection(int position) {
//TODO: implement
}
private void addAndMeasureChild(final View child, int viewPos) {
LayoutParams params = child.getLayoutParams();
if(params == null) {
params = new LayoutParams(LayoutParams.FILL_PARENT, LayoutParams.FILL_PARENT);
}
addViewInLayout(child, viewPos, params, true);
child.measure(MeasureSpec.makeMeasureSpec(getWidth(), MeasureSpec.AT_MOST),
MeasureSpec.makeMeasureSpec(getHeight(), MeasureSpec.AT_MOST));
}
@Override
protected synchronized void onLayout(boolean changed, int left, int top, int right, int bottom) {
super.onLayout(changed, left, top, right, bottom);
// if (mCurrentX == 0 && mNextX == 0 && mMaxX == 0)
// mMaxX = Integer.MAX_VALUE;
if(mAdapter == null){
return;
}
if(mDataChanged){
int oldCurrentX = mCurrentX;
initView();
removeAllViewsInLayout();
mNextX = oldCurrentX;
mDataChanged = false;
}
if(mScroller.computeScrollOffset()){
int scrollx = mScroller.getCurrX();
mNextX = scrollx;
}
if(mNextX <= 0){
mNextX = 0;
mScroller.forceFinished(true);
}
if(mNextX >= mMaxX) {
mNextX = mMaxX;
mScroller.forceFinished(true);
}
int dx = mCurrentX - mNextX;
removeNonVisibleItems(dx);
fillList(dx);
positionItems(dx);
mCurrentX = mNextX;
if(!mScroller.isFinished()){
post(new Runnable(){
@Override
public void run() {
requestLayout();
}
});
}
}
private void fillList(final int dx) {
int edge = 0;
View child = getChildAt(getChildCount()-1);
if(child != null) {
edge = child.getRight();
}
fillListRight(edge, dx);
edge = 0;
child = getChildAt(0);
if(child != null) {
edge = child.getLeft();
}
fillListLeft(edge, dx);
}
private void fillListRight(int rightEdge, final int dx) {
while(rightEdge + dx < getWidth() && mRightViewIndex < mAdapter.getCount()) {
View child = mAdapter.getView(mRightViewIndex, mRemovedViewQueue.poll(), this);
addAndMeasureChild(child, -1);
rightEdge += child.getMeasuredWidth();
if(mRightViewIndex == mAdapter.getCount()-1) {
mMaxX = mCurrentX + rightEdge - getWidth();
}
if (mMaxX < 0) {
mMaxX = 0;
}
mRightViewIndex++;
}
}
private void fillListLeft(int leftEdge, final int dx) {
while(leftEdge + dx > 0 && mLeftViewIndex >= 0) {
View child = mAdapter.getView(mLeftViewIndex, mRemovedViewQueue.poll(), this);
addAndMeasureChild(child, 0);
leftEdge -= child.getMeasuredWidth();
mLeftViewIndex--;
mDisplayOffset -= child.getMeasuredWidth();
}
}
private void removeNonVisibleItems(final int dx) {
View child = getChildAt(0);
while(child != null && child.getRight() + dx <= 0) {
mDisplayOffset += child.getMeasuredWidth();
mRemovedViewQueue.offer(child);
removeViewInLayout(child);
mLeftViewIndex++;
child = getChildAt(0);
}
child = getChildAt(getChildCount()-1);
while(child != null && child.getLeft() + dx >= getWidth()) {
mRemovedViewQueue.offer(child);
removeViewInLayout(child);
mRightViewIndex--;
child = getChildAt(getChildCount()-1);
}
}
private void positionItems(final int dx) {
if(getChildCount() > 0){
mDisplayOffset += dx;
int left = mDisplayOffset;
for(int i=0;i<getChildCount();i++){
View child = getChildAt(i);
int childWidth = child.getMeasuredWidth();
child.layout(left, 0, left + childWidth, child.getMeasuredHeight());
left += childWidth + child.getPaddingRight();
}
}
}
public synchronized void scrollTo(int x) {
mScroller.startScroll(mNextX, 0, x - mNextX, 0);
requestLayout();
}
@Override
public boolean dispatchTouchEvent(MotionEvent ev) {
boolean handled = super.dispatchTouchEvent(ev);
handled |= mGesture.onTouchEvent(ev);
return handled;
}
protected boolean onFling(MotionEvent e1, MotionEvent e2, float velocityX,
float velocityY) {
synchronized(HorizontalListView.this){
mScroller.fling(mNextX, 0, (int)-velocityX, 0, 0, mMaxX, 0, 0);
}
requestLayout();
return true;
}
protected boolean onDown(MotionEvent e) {
mScroller.forceFinished(true);
return true;
}
private OnGestureListener mOnGesture = new GestureDetector.SimpleOnGestureListener() {
@Override
public boolean onDown(MotionEvent e) {
return HorizontalListView.this.onDown(e);
}
@Override
public boolean onFling(MotionEvent e1, MotionEvent e2, float velocityX,
float velocityY) {
return HorizontalListView.this.onFling(e1, e2, velocityX, velocityY);
}
@Override
public boolean onScroll(MotionEvent e1, MotionEvent e2,
float distanceX, float distanceY) {
synchronized(HorizontalListView.this){
mNextX += (int)distanceX;
}
requestLayout();
return true;
}
@Override
public boolean onSingleTapConfirmed(MotionEvent e) {
for(int i=0;i<getChildCount();i++){
View child = getChildAt(i);
if (isEventWithinView(e, child)) {
if(mOnItemClicked != null){
mOnItemClicked.onItemClick(HorizontalListView.this, child, mLeftViewIndex + 1 + i, mAdapter.getItemId( mLeftViewIndex + 1 + i ));
}
if(mOnItemSelected != null){
mOnItemSelected.onItemSelected(HorizontalListView.this, child, mLeftViewIndex + 1 + i, mAdapter.getItemId( mLeftViewIndex + 1 + i ));
}
break;
}
}
return true;
}
@Override
public void onLongPress(MotionEvent e) {
int childCount = getChildCount();
for (int i = 0; i < childCount; i++) {
View child = getChildAt(i);
if (isEventWithinView(e, child)) {
if (mOnItemLongClicked != null) {
mOnItemLongClicked.onItemLongClick(HorizontalListView.this, child, mLeftViewIndex + 1 + i, mAdapter.getItemId(mLeftViewIndex + 1 + i));
}
break;
}
}
}
private boolean isEventWithinView(MotionEvent e, View child) {
Rect viewRect = new Rect();
int[] childPosition = new int[2];
child.getLocationOnScreen(childPosition);
int left = childPosition[0];
int right = left + child.getWidth();
int top = childPosition[1];
int bottom = top + child.getHeight();
viewRect.set(left, top, right, bottom);
return viewRect.contains((int) e.getRawX(), (int) e.getRawY());
}
};
}
公共类HorizontalListView扩展了AdapterView{
公共布尔值mAlwaysOverrideTouch=true;
保护列表适配器mAdapter;
private int mLeftViewIndex=-1;
private int mRightViewIndex=0;
受保护的int-mCurrentX;
受保护的int mNextX;
private int mMaxX=Integer.MAX_值;
私有整数mDisplayOffset=0;
保护滚轮;
私人手势;
私有队列mRemovedViewQueue=新链接列表();
private OnItemSelectedListener监视项Selected;
私有监听监听监听项被点击;
私有OnItemLongClickListener监视器LongClicked;
私有布尔值mDataChanged=false;
公共水平列表视图(上下文、属性集属性){
超级(上下文,attrs);
initView();
}
私有同步void initView(){
mLeftViewIndex=-1;
mRightViewIndex=0;
mDisplayOffset=0;
mCurrentX=0;
mNextX=0;
mMaxX=整数的最大值;
mScroller=新滚动条(getContext());
mGesture=新的手势检测器(getContext(),mOnGesture);
}
@凌驾
公共无效setOnItemSelectedListener(AdapterView.OnItemSelectedListener listener){
mOnItemSelected=侦听器;
}
@凌驾
public void setOnItemClickListener(AdapterView.OnItemClickListener侦听器){
mOnItemClicked=侦听器;
}
@凌驾
public void setOnItemLongClickListener(AdapterView.OnItemLongClickListener侦听器){
mOnItemLongClicked=listener;
}
私有DataSetoObserver mDataObserver=新DataSetoObserver(){
@凌驾
更改后的公共无效(){
已同步(HorizontalListView.this){
mDataChanged=true;
}
使无效();
//initView();
requestLayout();
}
@凌驾
未验证的公共无效(){
重置();
使无效();
requestLayout();
}
};
@凌驾
公共ListAdapter getAdapter(){
返回mAdapter;
}
@凌驾
公共视图getSelectedView(){
//TODO:实现
返回null;
}
@凌驾
public void setAdapter(ListAdapter适配器){
如果(mAdapter!=null){
mAdapter.unregisteredatasetobserver(mDataObserver);
}
mAdapter=适配器;
mAdapter.registerDataSetObserver(mDataObserver);
重置();
}
私有同步无效重置(){
initView();
removeAllViewsInLayout();
requestLayout();
}
@凌驾
公共选举(内部职位){
//TODO:实现
}
私有void add和measurechild(最终视图子视图,int-viewPos){
LayoutParams params=child.getLayoutParams();
if(params==null){
参数=新的LayoutParams(LayoutParams.FILL\u父级,LayoutParams.FILL\u父级);
}
addViewInLayout(子项、viewPos、参数、true);
measure(MeasureSpec.makeMeasureSpec(getWidth(),MeasureSpec.AT_至多),
MeasureSpec.makeMeasureSpec(getHeight(),MeasureSpec.AT_max));
}
@凌驾
受保护的同步void only布局(布尔值已更改、int left、int top、int right、int bottom){
超级。仅限布局(已更改、左、上、右、下);
//如果(mCurrentX==0&&mNextX==0&&mMaxX==0)
//mMaxX=整数的最大值;
if(mAdapter==null){
返回;
}
如果(mDataChanged){
int oldCurrentX=mCurrentX;
initView();
removeAllViewsInLayout();
mNextX=oldCurrentX;
mDataChanged=false;
}
if(mScroller.computeScrollOffset()){
int scrollx=mscroll.getCurrX();
mNextX=scrollx;
}
如果(mNextX=mMaxX){
mNextX=mMaxX;
mScroller.forceFinished(真);
}
int dx=mCurrentX-mNextX;
移除不可见项(dx);
填充列表(dx);
位置项目(dx);
mCurrentX=mNextX;
如果(!mScroller.isFinished()){
post(新的Runnable(){
@凌驾
公开募捐{
requestLayout();
}
});
}
}
专用空白填充列表(最终整数dx){
int-edge=0;
View child=getChildAt(getChildCount()-1);
if(child!=null){
edge=child.getRight();
}
fillListRight(边缘,dx);
边缘=0;
child=getChildAt(0);
if(child!=null){
edge=child.getLeft();
}
fillListLeft(边缘,dx);
}
私有void fillListRight(整型rightEdge,最终整型dx){
而(righedge+dxpublic synchronized void scrollTo(int x) {
mScroller.startScroll(mNextX, 0, x - mNextX, 0);
requestLayout();
}
final int x = newScrollPosition;
activity.runOnUiThread(new Runnable() {
public void run() {
horizontalListView.scrollTo(x);
}
});