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UITableView는 Facebook 애플리케이션처럼 하단으로 스크롤 할 때 더 많이로드됩니다.
SQLite를 사용하는 응용 프로그램을 개발 중입니다. 페이지 매기기 메커니즘을 사용하여 사용자 목록 (UITableView)을 표시하고 싶습니다. 사용자가 목록 끝으로 스크롤 할 때 내 목록에 더 많은 데이터를로드하는 방법을 알려주시겠습니까 (예 : Facebook 애플리케이션의 홈 페이지)?
cellForRowAtIndexPath:메서드 에서 현재 위치에 대한 확인을 추가하여이를 수행 할 수 있습니다 . 이 방법은 이해하고 구현하기 쉽습니다.
- (UITableViewCell *)tableView:(UITableView *)tableView cellForRowAtIndexPath:(NSIndexPath *)indexPath
{
// Classic start method
static NSString *cellIdentifier = @"MyCell";
MyCell *cell = [tableView dequeueReusableCellWithIdentifier:cellIdentifier];
if (!cell)
{
cell = [[MyCell alloc] initWithStyle:UITableViewCellStyleDefault reuseIdentifier:MainMenuCellIdentifier];
}
MyData *data = [self.dataArray objectAtIndex:indexPath.row];
// Do your cell customisation
// cell.titleLabel.text = data.title;
BOOL lastItemReached = [data isEqual:[[self.dataArray] lastObject]];
if (!lastItemReached && indexPath.row == [self.dataArray count] - 1)
{
[self launchReload];
}
}
편집 : 재귀 호출을 방지하기 위해 마지막 항목에 대한 검사를 추가했습니다. 마지막 항목에 도달했는지 여부를 정의하는 메서드를 구현해야합니다.
EDIT2 : lastItemReached 설명
빠른
방법 1 : 아래로 스크롤 했습니까?
다음은 Pedro Romão의 답변 의 Swift 버전입니다 . 사용자가 스크롤을 중지하면 하단에 도달했는지 확인합니다.
func scrollViewDidEndDragging(scrollView: UIScrollView, willDecelerate decelerate: Bool) {
// UITableView only moves in one direction, y axis
let currentOffset = scrollView.contentOffset.y
let maximumOffset = scrollView.contentSize.height - scrollView.frame.size.height
// Change 10.0 to adjust the distance from bottom
if maximumOffset - currentOffset <= 10.0 {
self.loadMore()
}
}
방법 2 : 마지막 행에 도달
그리고 여기 shinyuX의 대답 의 Swift 버전이 있습니다. 사용자가 마지막 행에 도달했는지 확인합니다.
func tableView(tableView: UITableView, cellForRowAtIndexPath indexPath: NSIndexPath) -> UITableViewCell {
// set up cell
// ...
// Check if the last row number is the same as the last current data element
if indexPath.row == self.dataArray.count - 1 {
self.loadMore()
}
}
loadMore()방법의 예
데이터 배치를 가져 오기 위해이 세 가지 클래스 변수를 설정했습니다.
// number of items to be fetched each time (i.e., database LIMIT)
let itemsPerBatch = 50
// Where to start fetching items (database OFFSET)
var offset = 0
// a flag for when all database items have already been loaded
var reachedEndOfItems = false
데이터베이스에서 더 많은 항목을 테이블보기로로드하는 기능입니다.
func loadMore() {
// don't bother doing another db query if already have everything
guard !self.reachedEndOfItems else {
return
}
// query the db on a background thread
DispatchQueue.global(qos: .background).async {
// determine the range of data items to fetch
var thisBatchOfItems: [MyObjects]?
let start = self.offset
let end = self.offset + self.itemsPerBatch
// query the database
do {
// SQLite.swift wrapper
thisBatchOfItems = try MyDataHelper.findRange(start..<end)
} catch _ {
print("query failed")
}
// update UITableView with new batch of items on main thread after query finishes
DispatchQueue.main.async {
if let newItems = thisBatchOfItems {
// append the new items to the data source for the table view
self.myObjectArray.appendContentsOf(newItems)
// reload the table view
self.tableView.reloadData()
// check if this was the last of the data
if newItems.count < self.itemsPerBatch {
self.reachedEndOfItems = true
print("reached end of data. Batch count: \(newItems.count)")
}
// reset the offset for the next data query
self.offset += self.itemsPerBatch
}
}
}
}
willDisplayCell어떤 셀이로드되는지 확인 하는 방법 을 사용 하는 것이 좋습니다. 전류 indexPath.row가 마지막이 되면 더 많은 셀을로드 할 수 있습니다. 아래로 스크롤하면 더 많은 셀이로드됩니다.
- (void)tableView:(UITableView *)tableView
willDisplayCell:(UITableViewCell *)cell
forRowAtIndexPath:(NSIndexPath *)indexPath
{
// check if indexPath.row is last row
// Perform operation to load new Cell's.
}
- (void)tableView:(UITableView *)tableView willDisplayCell:(UITableViewCell *)cell forRowAtIndexPath:(NSIndexPath *)indexPath {
NSInteger lastSectionIndex = [tableView numberOfSections] - 1;
NSInteger lastRowIndex = [tableView numberOfRowsInSection:lastSectionIndex] - 1;
if ((indexPath.section == lastSectionIndex) && (indexPath.row == lastRowIndex)) {
// This is the last cell
[self loadMore];
}
}
당신이 코어 데이터를 사용하는 경우 NSFetchedResultsController, 다음 loadMore다음과 같이 수 :
// Load more
- (void)loadMore {
[self.fetchedResultsController.fetchRequest setFetchLimit:newFetchLimit];
[NSFetchedResultsController deleteCacheWithName:@"cache name"];
NSError *error;
if (![self.fetchedResultsController performFetch:&error]) {
// Update to handle the error appropriately.
NSLog(@"Unresolved error %@, %@", error, [error userInfo]);
}
[self.tableView reloadData];
}
세부
- Xcode 10, Swift 4.2
- Xcode 10.2 (10E125), Swift 5
해결책
UIScrollView / UICollectionView / UITableView로 작업
import UIKit
protocol LoadMoreControlDelegate: class {
func loadMoreControl(didStartAnimating loadMoreControl: LoadMoreControl)
func loadMoreControl(didStopAnimating loadMoreControl: LoadMoreControl)
}
class LoadMoreControl {
private let spacingFromLastCell: CGFloat
private let indicatorHeight: CGFloat
private weak var activityIndicatorView: UIActivityIndicatorView?
private weak var scrollView: UIScrollView?
weak var delegate: LoadMoreControlDelegate?
private var defaultY: CGFloat {
guard let height = scrollView?.contentSize.height else { return 0.0 }
return height + spacingFromLastCell
}
init (scrollView: UIScrollView, spacingFromLastCell: CGFloat, indicatorHeight: CGFloat) {
self.scrollView = scrollView
self.spacingFromLastCell = spacingFromLastCell
self.indicatorHeight = indicatorHeight
let size:CGFloat = 40
let frame = CGRect(x: (scrollView.frame.width-size)/2, y: scrollView.contentSize.height + spacingFromLastCell, width: size, height: size)
let activityIndicatorView = UIActivityIndicatorView(frame: frame)
activityIndicatorView.color = .black
activityIndicatorView.hidesWhenStopped = true
activityIndicatorView.autoresizingMask = [.flexibleLeftMargin, .flexibleRightMargin]
scrollView.addSubview(activityIndicatorView)
activityIndicatorView.isHidden = isHidden
self.activityIndicatorView = activityIndicatorView
}
private var isHidden: Bool {
guard let scrollView = scrollView else { return true }
return scrollView.contentSize.height < scrollView.frame.size.height
}
func didScroll() {
guard let scrollView = scrollView, let activityIndicatorView = activityIndicatorView else { return }
let offsetY = scrollView.contentOffset.y
activityIndicatorView.isHidden = isHidden
if !activityIndicatorView.isHidden && offsetY >= 0 {
let contentDelta = scrollView.contentSize.height - scrollView.frame.size.height
let offsetDelta = offsetY - contentDelta
let newY = defaultY-offsetDelta
if newY < scrollView.frame.height {
activityIndicatorView.frame.origin.y = newY
} else {
if activityIndicatorView.frame.origin.y != defaultY {
activityIndicatorView.frame.origin.y = defaultY
}
}
if !activityIndicatorView.isAnimating {
if offsetY > contentDelta && offsetDelta >= indicatorHeight && !activityIndicatorView.isAnimating {
activityIndicatorView.startAnimating()
delegate?.loadMoreControl(didStartAnimating: self)
}
}
if scrollView.isDecelerating {
if activityIndicatorView.isAnimating && scrollView.contentInset.bottom == 0 {
UIView.animate(withDuration: 0.3) { [weak self, weak scrollView] in
if let bottom = self?.indicatorHeight {
scrollView?.contentInset = UIEdgeInsets(top: 0, left: 0, bottom: bottom, right: 0)
}
}
}
}
}
}
func stop() {
guard let scrollView = scrollView else { return }
let contentDelta = scrollView.contentSize.height - scrollView.frame.size.height
let offsetDelta = scrollView.contentOffset.y - contentDelta
if offsetDelta >= 0 {
UIView.animate(withDuration: 0.3, animations: { [weak scrollView] in
scrollView?.contentInset = .zero
}) { [weak self] result in
if result { self?.endAnimating() }
}
} else {
scrollView.contentInset = .zero
endAnimating()
}
}
private func endAnimating() {
activityIndicatorView?.stopAnimating()
delegate?.loadMoreControl(didStopAnimating: self)
}
}
용법
초기화
loadMoreControl = LoadMoreControl(scrollView: tableView, spacingFromLastCell: 10, indicatorHeight: 60)
loadMoreControl.delegate = self
손질
extension ViewController: LoadMoreControlDelegate {
func loadMoreControl(didStartAnimating loadMoreControl: LoadMoreControl) {
print("didStartAnimating")
}
func loadMoreControl(didStopAnimating loadMoreControl: LoadMoreControl) {
print("didStopAnimating")
}
}
extension ViewController: UITableViewDelegate {
func scrollViewDidScroll(_ scrollView: UIScrollView) {
loadMoreControl.didScroll()
}
}
전체 샘플
솔루션 코드를 붙여 넣는 것을 잊지 마십시오.
import UIKit
class ViewController: UIViewController {
fileprivate var activityIndicator: LoadMoreActivityIndicator!
override func viewDidLoad() {
super.viewDidLoad()
let tableView = UITableView(frame: view.frame)
view.addSubview(tableView)
tableView.translatesAutoresizingMaskIntoConstraints = false
tableView.topAnchor.constraint(equalTo: view.topAnchor).isActive = true
tableView.bottomAnchor.constraint(equalTo: view.bottomAnchor).isActive = true
tableView.leftAnchor.constraint(equalTo: view.leftAnchor).isActive = true
tableView.rightAnchor.constraint(equalTo: view.rightAnchor).isActive = true
tableView.dataSource = self
tableView.delegate = self
tableView.tableFooterView = UIView()
activityIndicator = LoadMoreActivityIndicator(scrollView: tableView, spacingFromLastCell: 10, spacingFromLastCellWhenLoadMoreActionStart: 60)
}
}
extension ViewController: UITableViewDataSource {
func numberOfSections(in tableView: UITableView) -> Int {
return 1
}
func tableView(_ tableView: UITableView, numberOfRowsInSection section: Int) -> Int {
return 30
}
func tableView(_ tableView: UITableView, cellForRowAt indexPath: IndexPath) -> UITableViewCell {
let cell = UITableViewCell()
cell.textLabel?.text = "\(indexPath)"
return cell
}
}
extension ViewController: UITableViewDelegate {
func scrollViewDidScroll(_ scrollView: UIScrollView) {
activityIndicator.start {
DispatchQueue.global(qos: .utility).async {
for i in 0..<3 {
print("!!!!!!!!! \(i)")
sleep(1)
}
DispatchQueue.main.async { [weak self] in
self?.activityIndicator.stop()
}
}
}
}
}
결과
나는 stackoverflow에서 찾은 하나의 솔루션을 구현했으며 잘 작동하지만 shinyuX의 솔루션은 구현하기가 매우 쉽고 내 제안에 잘 작동한다고 생각합니다. 누군가 다른 솔루션을 원한다면 아래에서 이것을 사용할 수 있습니다.
- (void)scrollViewDidEndDragging:(UIScrollView *)scrollView willDecelerate:(BOOL)decelerate{
// UITableView only moves in one direction, y axis
CGFloat currentOffset = scrollView.contentOffset.y;
CGFloat maximumOffset = scrollView.contentSize.height - scrollView.frame.size.height;
//NSInteger result = maximumOffset - currentOffset;
// Change 10.0 to adjust the distance from bottom
if (maximumOffset - currentOffset <= 10.0) {
[self loadOneMorePage];
//[self methodThatAddsDataAndReloadsTableView];
}
}
쿼리에서 제한 및 오프셋을 사용하고 해당 콘텐츠로 테이블 뷰를 채 웁니다. 사용자가 아래로 스크롤하면 다음 오프셋을로드합니다.
tableView:willDisplayCell:forRowAtIndexPath:메서드를 구현하고 UITableViewDelegate마지막 행인지 확인하십시오.
아래 링크는 샘플 코드를 제공합니다. # Swift3
사용자는 서버에서 더 많은 데이터를 가져 오려면 마지막 테이블보기 셀 (최소 2 셀 높이)을 가져와야합니다.
마지막 셀에서와 같이로드 프로세스를 표시하는 프로세스 셀도 찾을 수 있습니다.
그것의 Swift3
https://github.com/yogendrabagoriya/YBTableViewPullData
사용할 수있는 또 하나의 옵션 ( Swift 3 및 iOS 10 이상) :
class DocumentEventsTableViewController: UITableViewController, UITableViewDataSourcePrefetching {
var currentPage: Int = 1
let pageSize: Int = 10 // num of items in one page
override func viewDidLoad() {
super.viewDidLoad()
self.tableView.prefetchDataSource = self
}
func tableView(_ tableView: UITableView, prefetchRowsAt indexPaths: [IndexPath]) {
let upcomingRows = indexPaths.map { $0.row }
if let maxIndex = upcomingRows.max() {
let nextPage: Int = Int(ceil(Double(maxIndex) / Double(pageSize))) + 1
if nextPage > currentPage {
// Your function, which attempts to load respective page from the local database
loadLocalData(page: nextPage)
// Your function, which makes a network request to fetch the respective page of data from the network
startLoadingDataFromNetwork(page: nextPage)
currentPage = nextPage
}
}
}
}
다소 작은 페이지 (~ 10 개 항목)의 경우 테이블에서 잘 스크롤 할 항목이 몇 개있을 때까지 nextPage가 약 1-2에있을 수 있으므로 페이지 1과 2에 대한 데이터를 수동으로 추가 할 수 있습니다. 그러나 다음 페이지에서 모두 잘 작동합니다.
- (NSInteger)tableView:(UITableView *)tableView numberOfRowsInSection:(NSInteger)section {
if (news.count == 0) {
return 0;
} else {
return news.count + 1 ;
}
}
- (UITableViewCell *)tableView:(UITableView *)tableView cellForRowAtIndexPath:(NSIndexPath *)indexPath {
@try {
uint position = (uint) (indexPath.row);
NSUInteger row = [indexPath row];
NSUInteger count = [news count];
//show Load More
if (row == count) {
UITableViewCell *cell = nil;
static NSString *LoadMoreId = @"LoadMore";
cell = [tableView dequeueReusableCellWithIdentifier:LoadMoreId];
if (cell == nil) {
cell = [[UITableViewCell alloc]
initWithStyle:UITableViewCellStyleDefault
reuseIdentifier:LoadMoreId];
}
if (!hasMoreLoad) {
cell.hidden = true;
} else {
cell.textLabel.text = @"Load more items...";
cell.textLabel.textColor = [UIColor blueColor];
cell.textLabel.font = [UIFont boldSystemFontOfSize:14];
NSLog(@"Load more");
if (!isMoreLoaded) {
isMoreLoaded = true;
[self performSelector:@selector(loadMoreNews) withObject:nil afterDelay:0.1];
}
}
return cell;
} else {
NewsRow *cell = nil;
NewsObject *newsObject = news[position];
static NSString *CellIdentifier = @"NewsRow";
cell = [tableView dequeueReusableCellWithIdentifier:CellIdentifier];
if (cell == nil) {
// Load the top-level objects from the custom cell XIB.
NSArray *topLevelObjects = [[NSBundle mainBundle] loadNibNamed:CellIdentifier owner:self options:nil];
// Grab a pointer to the first object (presumably the custom cell, as that's all the XIB should contain).
cell = topLevelObjects[0];
// Configure the cell...
}
cell.title.text = newsObject.title;
return cell;
}
}
@catch (NSException *exception) {
NSLog(@"Exception occurred: %@, %@", exception, [exception userInfo]);
}
return nil;
}
이 게시물에 대한 아주 좋은 설명.
http://useyourloaf.com/blog/2010/10/02/dynamically-loading-new-rows-into-a-table.html
간단하게 마지막 행을 추가하고 숨기고 테이블 행이 마지막 행에 도달하면 행을 표시하고 더 많은 항목을로드하는 것보다 간단합니다.
ios UITableViewDataSourcePrefetching을 확인해야합니다.
class ViewController: UIViewController {
@IBOutlet weak var mytableview: UITableView!
override func viewDidLoad() {
super.viewDidLoad()
mytableview.prefetchDataSource = self
}
func tableView(_ tableView: UITableView, prefetchRowsAt indexPaths: [IndexPath]) {
print("prefetchdRowsAtIndexpath \(indexPaths)")
}
func tableView(_ tableView: UITableView, cancelPrefetchingForRowsAt indexPaths: [IndexPath]) {
print("cancelPrefetchingForRowsAtIndexpath \(indexPaths)")
}
}
- https://developer.apple.com/documentation/uikit/uitableviewdatasourceprefetching https://andreygordeev.com/2017/02/20/uitableview-prefetching/
API에서로드하기 위해 Xcode 10 , swift 4.2 작동합니다 .
1- 새 Swift 파일을 만들고 다음과 같이하십시오.
//
// apiTVCController.swift
// ApiTestingTableView
//
// Created by Hooma7n on 4/7/19.
// Copyright © 2019 Hooma7n. All rights reserved.
//
import Foundation
import Alamofire
class apiget {
var tableData : [Datum] = []
var loadin : [Datum] = []
var testfortotal : Int?
func getfromapi(completionHandler : ((_ isSucess : Bool) -> Void)?) {
let url = "https://reqres.in/api/users?page=1"
Alamofire.request(url, method: .get, parameters: nil, encoding: JSONEncoding.default, headers: nil)
.responseJSON(completionHandler : { response in
switch response.result {
case .success(let data):
guard let jsonData = try? JSONSerialization.data(withJSONObject: data, options: JSONSerialization.WritingOptions.prettyPrinted) else {return}
let decoder = JSONDecoder()
guard let result = try? decoder.decode(Welcome.self, from: jsonData) else {return}
self.tableData = result.data ?? []
self.testfortotal = result.total ?? 0
completionHandler?(true)
// print(result)
case .failure(let error):
print(error)
}
})
}
var pagecounter : Int = 2
func loadmore(completionHandler : ((_ isSucess : Bool) -> Void)?){
let url = "https://reqres.in/api/users?page=\(pagecounter)"
Alamofire.request(url, method: .get, parameters: nil, encoding: JSONEncoding.default, headers: nil)
.responseJSON(completionHandler : { response in
switch response.result {
case .success(let data):
guard let jsonData = try? JSONSerialization.data(withJSONObject: data, options: JSONSerialization.WritingOptions.prettyPrinted) else {return}
let decoder = JSONDecoder()
guard let myresult = try? decoder.decode(Welcome.self, from: jsonData) else {return}
self.loadin = myresult.data ?? []
self.tableData.append(contentsOf: myresult.data ?? [])
completionHandler?(true)
print(self.pagecounter)
self.pagecounter += 1
// print(myresult)
case .failure(let error):
print(error)
}
})
}
}
extension apiget {
struct Welcome: Codable {
let page, perPage, total, totalPages: Int?
var data: [Datum]?
enum CodingKeys: String, CodingKey {
case page
case perPage = "per_page"
case total
case totalPages = "total_pages"
case data
}
}
struct Datum: Codable {
let id: Int?
let firstName, lastName: String?
let avatar: String?
enum CodingKeys: String, CodingKey {
case id
case firstName = "first_name"
case lastName = "last_name"
case avatar
}
}
}
2- ViewController 파일 (tableView Controller) :
//
// apiTVC.swift
// ApiTestingTableView
//
// Created by Hooma7n on 4/7/19.
// Copyright © 2019 Hooma7n. All rights reserved.
//
import UIKit
import Alamofire
class apiTVC: UITableViewController {
var datamodel = apiget()
override func viewDidLoad() {
super.viewDidLoad()
datamodel.getfromapi(completionHandler: {finish in
if finish {self.tableView.reloadData()
}
})
}
override func numberOfSections(in tableView: UITableView) -> Int {
return 1
}
override func tableView(_ tableView: UITableView, numberOfRowsInSection section: Int) -> Int {
return datamodel.tableData.count
}
override func tableView(_ tableView: UITableView, cellForRowAt indexPath: IndexPath) -> UITableViewCell {
let cell = tableView.dequeueReusableCell(withIdentifier: "Cell", for: indexPath) as! apiTableViewCell
cell.firstNameLabel.text = datamodel.tableData[indexPath.row].firstName
cell.lastNameLabel.text = datamodel.tableData[indexPath.row].lastName
cell.dateLabel.text = "\(datamodel.tableData[indexPath.row].id ?? 0)"
cell.profileImageView.loadImage(fromURL: datamodel.tableData[indexPath.row].avatar ?? "")
return cell
}
override func tableView(_ tableView: UITableView, willDisplay cell: UITableViewCell, forRowAt indexPath: IndexPath) {
let lastElement = datamodel.tableData.count - 1
let total = datamodel.testfortotal ?? 12
if indexPath.row == lastElement && datamodel.tableData.count < total{
datamodel.loadmore(completionHandler: {finish in
if finish {
self.tableView.reloadData()
}})
}
}
}
귀하의 ViewController 세트에있는 tableView를 사용하는 경우 위임 , 데이터 소스 의 viewDidLoad에서 자체.
이 접근 방식을 공유하고 싶습니다.
- (void)scrollViewDidEndDecelerating:(UIScrollView *)scrollView
{
NSLog(@"%@", [[YourTableView indexPathsForVisibleRows] lastObject]);
[self estimatedTotalData];
}
- (void)estimatedTotalData
{
long currentRow = ((NSIndexPath *)[[YourTableView indexPathsForVisibleRows] lastObject]).row;
long estimateDataCount = 25;
while (currentRow > estimateDataCount)
{
estimateDataCount+=25;
}
dataLimit = estimateDataCount;
if (dataLimit == currentRow+1)
{
dataLimit+=25;
}
NSLog(@"dataLimit :%ld", dataLimit);
[self requestForData];
// this answers the question..
//
if(YourDataSource.count-1 == currentRow)
{
NSLog(@"LAST ROW"); //loadMore data
}
}
NSLog(...); 출력은 다음과 같습니다.
<NSIndexPath: 0xc0000000002e0016> {length = 2, path = 0 - 92}
dataLimit :100
<NSIndexPath: 0xc000000000298016> {length = 2, path = 0 - 83}
dataLimit :100
<NSIndexPath: 0xc000000000278016> {length = 2, path = 0 - 79}
dataLimit :100
<NSIndexPath: 0xc000000000238016> {length = 2, path = 0 - 71}
dataLimit :75
<NSIndexPath: 0xc0000000001d8016> {length = 2, path = 0 - 59}
dataLimit :75
<NSIndexPath: 0xc0000000001c0016> {length = 2, path = 0 - 56}
dataLimit :75
<NSIndexPath: 0xc000000000138016> {length = 2, path = 0 - 39}
dataLimit :50
<NSIndexPath: 0xc000000000120016> {length = 2, path = 0 - 36}
dataLimit :50
<NSIndexPath: 0xc000000000008016> {length = 2, path = 0 - 1}
dataLimit :25
<NSIndexPath: 0xc000000000008016> {length = 2, path = 0 - 1}
dataLimit :25
이것은 로컬에 저장된 데이터를 표시하는 데 유용합니다. 처음에는 dataLimit를 25로 선언합니다. 즉, uitableview가 처음에는 0-24를 갖게됩니다.
사용자가 맨 아래로 스크롤하고 마지막 셀이 표시 dataLimit되면 25 ...
참고 : 이것은 UITableView 데이터 페이징과 비슷합니다. :)
-(void)tableView:(UITableView *)tableView willDisplayCell:(UITableViewCell *)cell forRowAtIndexPath:(NSIndexPath *)indexPath {
NSInteger sectionsAmount = [tableView numberOfSections];
NSInteger rowsAmount = [tableView numberOfRowsInSection:[indexPath section]];
if ([indexPath section] == sectionsAmount - 1 && [indexPath row] == rowsAmount - 1) {
//get last row
if (!isSearchActive && !isFilterSearchActive) {
if (totalRecords % 8 == 0) {
int64_t delayInSeconds = 2.0;
dispatch_time_t popTime = dispatch_time(DISPATCH_TIME_NOW, delayInSeconds * NSEC_PER_SEC);
dispatch_after(popTime, dispatch_get_main_queue(), ^(void) {
[yourTableView beginUpdates];
[yourTableView insertRowsAtIndexPaths:indexPaths withRowAnimation:UITableViewRowAnimationAutomatic];
[yourTableView endUpdates];
});
}
}
}
}
이 문제를 해결하는 가장 좋은 방법은 표 하단에 셀을 추가하는 것입니다.이 셀에는 표시기가 있습니다.
신속하게 다음을 추가해야합니다.
- cellLoading 유형의 새 셀을 생성하면 표시기가 유지됩니다. 아래 코드를보세요
- 행 수를보고 여기에 1을 더합니다 (셀을로드하기위한 것입니다).
- idexPath.row == yourArray.count 인 경우 rawAtIndex를 확인한 다음 Loading 셀을 반환해야합니다.
아래 코드를보십시오.
import UIKit
class LoadingCell: UITableViewCell {
@IBOutlet weak var indicator: UIActivityIndicatorView!
}
테이블보기 : numOfRows :
func tableView(_ tableView: UITableView, numberOfRowsInSection section: Int) -> Int {
return yourArray.count + 1
}
cellForRawAt indexPath :
func tableView(_ tableView: UITableView, cellForRowAt indexPath: IndexPath) -> UITableViewCell {
if indexPath.row == users.count {
// need to change
let loading = Bundle.main.loadNibNamed("LoadingCell", owner: LoadingCell.self , options: nil)?.first as! LoadingCell
return loading
}
let yourCell = tableView.dequeueReusableCell(withIdentifier: "cellCustomizing", for: indexPath) as! UITableViewCell
return yourCell
}
내 로딩 셀이 nib 파일에서 생성 된 것을 확인한 경우. 이 비디오 는 제가 한 일을 설명합니다.
let threshold = 100.0 // threshold from bottom of tableView
var isLoadingMore = false // flag
func scrollViewDidScroll(scrollView: UIScrollView) {
let contentOffset = scrollView.contentOffset.y
let maximumOffset = scrollView.contentSize.height - scrollView.frame.size.height;
if !isLoadingMore && (maximumOffset - contentOffset <= threshold) {
// Get more data - API call
self.isLoadingMore = true
// Update UI
dispatch_async(dispatch_get_main_queue()) {
tableView.reloadData()
self.isLoadingMore = false
}
}
}
Xcode 10.1, Swift 4.2의 경우
이 비디오 는 훌륭한 튜토리얼처럼 보입니다!
시작 / 완료 프로젝트 : https://github.com/RobCanton/Swift-Infinite-Scrolling-Example
import UIKit
class ViewController: UIViewController, UITableViewDataSource, UITableViewDelegate {
var tableView:UITableView!
var fetchingMore = false
var items = [0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15]
override func viewDidLoad() {
super.viewDidLoad()
// Do any additional setup after loading the view, typically from a nib.
initTableView()
}
func initTableView() {
tableView = UITableView(frame: view.bounds, style: .plain)
tableView.register(UITableViewCell.self, forCellReuseIdentifier: "tableCell")
tableView.delegate = self
tableView.dataSource = self
view.addSubview(tableView)
tableView.translatesAutoresizingMaskIntoConstraints = false
let layoutGuide = view.safeAreaLayoutGuide
tableView.leadingAnchor.constraint(equalTo: layoutGuide.leadingAnchor).isActive = true
tableView.topAnchor.constraint(equalTo: layoutGuide.topAnchor).isActive = true
tableView.trailingAnchor.constraint(equalTo: layoutGuide.trailingAnchor).isActive = true
tableView.bottomAnchor.constraint(equalTo: layoutGuide.bottomAnchor).isActive = true
tableView.reloadData()
}
override func didReceiveMemoryWarning() {
super.didReceiveMemoryWarning()
// Dispose of any resources that can be recreated.
}
func tableView(_ tableView: UITableView, numberOfRowsInSection section: Int) -> Int {
return items.count
}
func tableView(_ tableView: UITableView, cellForRowAt indexPath: IndexPath) -> UITableViewCell {
let cell = tableView.dequeueReusableCell(withIdentifier: "tableCell", for: indexPath)
cell.textLabel?.text = "Item \(items[indexPath.row])"
return cell
}
func scrollViewDidScroll(_ scrollView: UIScrollView) {
let offsetY = scrollView.contentOffset.y
let contentHeight = scrollView.contentSize.height
if offsetY > contentHeight - scrollView.frame.height * 4 {
if !fetchingMore {
beginBatchFetch()
}
}
}
func beginBatchFetch() {
fetchingMore = true
print("Call API here..")
DispatchQueue.main.asyncAfter(deadline: .now() + 0.50, execute: {
print("Consider this as API response.")
let newItems = (self.items.count...self.items.count + 12).map { index in index }
self.items.append(contentsOf: newItems)
self.fetchingMore = false
self.tableView.reloadData()
})
}
}
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