public class CustomListView extends ListView implements NestedScrollingChild, AbsListView.OnScrollListener {
/**
* 滚动到底部回掉接口
*/
public interface OnBottonListener {
/**
* 加载更多
*/
public void loadMore();
}
//footer XML布局
private View footerView;
private ImageView footerImg;
private TextView footerText;
private int firstItemIndex;
private int currentScrollState;
private OnBottonListener onBottonListener;
private View placeholder_listview_headerview;
/**
* 每页总数
*/
private int pageSize = 10;
/**
* 满足查询条件的总数
*/
private long total = 0;
private NestedScrollingChildHelper mNestedScrollingChildHelper;
public CustomListView(final Context context) {
super(context);
initHelper();
init(context);
}
public CustomListView(final Context context, final AttributeSet attrs) {
super(context, attrs);
initHelper();
init(context);
}
public CustomListView(final Context context, final AttributeSet attrs, final int defStyleAttr) {
super(context, attrs, defStyleAttr);
initHelper();
init(context);
}
@TargetApi(Build.VERSION_CODES.LOLLIPOP)
public CustomListView(final Context context, final AttributeSet attrs, final int defStyleAttr, final int defStyleRes) {
super(context, attrs, defStyleAttr, defStyleRes);
initHelper();
init(context);
}
private void initHelper() {
mNestedScrollingChildHelper = new NestedScrollingChildHelper(this);
setNestedScrollingEnabled(true);
}
@Override
public void setNestedScrollingEnabled(final boolean enabled) {
mNestedScrollingChildHelper.setNestedScrollingEnabled(enabled);
}
@Override
public boolean isNestedScrollingEnabled() {
return mNestedScrollingChildHelper.isNestedScrollingEnabled();
}
@Override
public boolean startNestedScroll(final int axes) {
return mNestedScrollingChildHelper.startNestedScroll(axes);
}
@Override
public void stopNestedScroll() {
mNestedScrollingChildHelper.stopNestedScroll();
}
@Override
public boolean hasNestedScrollingParent() {
return mNestedScrollingChildHelper.hasNestedScrollingParent();
}
@Override
public boolean dispatchNestedScroll(final int dxConsumed, final int dyConsumed, final int dxUnconsumed, final int dyUnconsumed, final int[] offsetInWindow) {
return mNestedScrollingChildHelper.dispatchNestedScroll(dxConsumed, dyConsumed, dxUnconsumed, dyUnconsumed, offsetInWindow);
}
@Override
public boolean dispatchNestedPreScroll(final int dx, final int dy, final int[] consumed, final int[] offsetInWindow) {
return mNestedScrollingChildHelper.dispatchNestedPreScroll(dx, dy, consumed, offsetInWindow);
}
@Override
public boolean dispatchNestedFling(final float velocityX, final float velocityY, final boolean consumed) {
return mNestedScrollingChildHelper.dispatchNestedFling(velocityX, velocityY, consumed);
}
@Override
public boolean dispatchNestedPreFling(final float velocityX, final float velocityY) {
return mNestedScrollingChildHelper.dispatchNestedPreFling(velocityX, velocityY);
}
/**
* 初始化
*/
private void init(Context context) {
// footerView
LayoutInflater inflater = (LayoutInflater) getContext().getSystemService(Context.LAYOUT_INFLATER_SERVICE);
footerView = inflater.inflate(R.layout.addmore_listview_footer, null);
footerImg = (ImageView) footerView.findViewById(R.id.loadMoreImg);
footerText = (TextView) footerView.findViewById(R.id.loadMoreHintTv);
footerView.setTag(true);
//占位，让可以在setAdapter之后调用addFooterView有效果
placeholder_listview_headerview = inflater.inflate(R.layout.placeholder_listview_headerview, null);
addFooterView(placeholder_listview_headerview, null, false);
setOnScrollListener(this);
}
/**
* 对比每页总数和满足条件的所有条数。应该在onScrollStateChanged设置，
* 当total > pageSize时滚动条触底才能出现加载更多的footerView。
* 注意：必须在具体的应用中调用。
*/
public void setIsAddFooterView(int pageSize, Long total) {
this.pageSize = pageSize;
this.total = total;
}
@Override
public void onScrollStateChanged(AbsListView view, int scrollState) {
currentScrollState = scrollState;
int lastIndex = view.getLastVisiblePosition();// 适配器数据集在屏幕中显示的最后一项
int viewCount = view.getCount() - 1; // 适配器中包含的view的总条目数
// 列表为空
if (viewCount <= 0) {
return;
}
switch (scrollState) {
case SCROLL_STATE_IDLE: // 停止滚动
boolean hasAddFooterView = (Boolean) footerView.getTag();
if (lastIndex == viewCount && hasAddFooterView && pageSize < total) { // 滚动到最后一项目
addListFooterView();
onBottonListener.loadMore();
}
break;
default:
break;
}
}
@Override
public void onScroll(AbsListView view, int firstVisibleItem, int visibleItemCount, int totalItemCount) {
firstItemIndex = firstVisibleItem;
}
/**
* 添加列表页脚
*/
public View addListFooterView() {
footerView.setVisibility(VISIBLE);
footerView.setTag(false);
footerImg.setVisibility(View.VISIBLE);
footerText.setText("努力加载中……");
addFooterView(footerView, null, false);
//选定当前项
setSelection(getLastVisiblePosition());
// 设置图标动画
Animation operatingAnim = AnimationUtils.loadAnimation(getContext(),
R.anim.loading_more_anim);
footerImg.startAnimation(operatingAnim);
return footerView;
}
/**
* 根据各种加载状态设置页脚文字
*
* @param status 加载更多失败的状态 “1”：已经加载完毕，没有更多数据 “2”：加载更多失败，可能是网络不好等
* @param text 对应状态下的文字提示
*/
public void setFooterViewText(int status, String text) {
if (!(Boolean) footerView.getTag()) {
footerText.setText(text);
footerImg.clearAnimation();
footerImg.setVisibility(View.GONE);
if (status == 2) {
footerView.setOnClickListener(new OnClickListener() {
@Override
public void onClick(View v) {
onClickFooterToReloadMore();
}
});
}
}
}
/**
* 点击页脚重新加载更多
*/
private void onClickFooterToReloadMore() {
removeListFooterView();
addListFooterView();
onBottonListener.loadMore();
}
/**
* 加载更多后，移除页脚
*/
public void removeListFooterView() {
footerView.setTag(true);
footerImg.clearAnimation(); // 清除动画
removeFooterView(footerView);
}
public OnBottonListener getOnBottonListener() {
return onBottonListener;
}
public void setOnBottonListener(OnBottonListener onBottonListener) {
this.onBottonListener = onBottonListener;
}
}
