我正在使用集合视图来显示结果。我想在选择该单元格时删除特定单元格。为了保留所选单元格的记录，我正在使用struct.Everything正常工作。但是当我点击删除按钮时，所选单元格没有被删除。其他一些单元格被删除。但是当我回到上一个屏幕并再次返回时，我想要删除的单元格实际上被删除了。我不知道为什么以及如何发生这种情况？
import UIKit
import GRDBCipher
class AdvisoryViewController:
UIViewController,UICollectionViewDelegate,UICollectionViewDataSource {
@IBOutlet weak var new_advisory_label: UILabel!
var getname=String()
var array=[String]()
var date_array=[String]()
var crop_code:String=""
var dbQueue:DatabaseQueue? = nil
var ss = [Int]()
var struct_array :[myObject] = []
var msg_stat:[oldMsg] = []
var msg_count_array=[Int]()
var msg_array=[String]()
var selected_date_array=[String]()
var srno_array=[String]()
var selected_srno_array=[String]()
@IBOutlet weak var collection_view: UICollectionView!
struct myObject
{
var date: String
var advisory:String
var status: String
var srno: String
}
struct oldMsg
{
var is_checked: Bool
}
override func viewDidLoad() {
super.viewDidLoad()
do{
let longpress1=UILongPressGestureRecognizer(target: self, action: #selector(longpress))
// longpress1.minimumPressDuration=1
collection_view.addGestureRecognizer(longpress1)
let
path=NSSearchPathForDirectoriesInDomains(.documentDirectory,.userDomainMask,
true).first!
dbQueue = try DatabaseQueue(path: "\(path)/pest_messenger.sqlite")
try dbQueue?.inDatabase { db in
let crop_sursor = try Row.fetchCursor(db, "SELECT * FROM crop_master where crop_name='\(getname)'")
while let row = try crop_sursor.next() {
let title: String = row.value(named: "srno")
crop_code=title
}
let rows = try Row.fetchCursor(db, "SELECT distinct brief_advisory,advisory_date,srno FROM crop_insect_advisory_issued where crop_code='\(crop_code)'")
while let row = try rows.next() {
let title: String = row.value(named: "brief_advisory")
let da:String=row.value(named:"advisory_date")
let srno:Int = row.value(named:"srno")
let date_f=DateFormatter()
date_f.dateFormat="yyyy-MM-dd"
let d=date_f.date(from: da)
date_f.dateFormat="dd-MM-yyyy"
let dd=date_f.string(from: d!)
array.append(title)
date_array.append(dd)
srno_array.append("\(srno)")
}
}
for i in 0 ..< array.count
{
struct_array.append(myObject(date:date_array[i],advisory:array[i],
status:"N",srno:srno_array[i]))
}
for i in 0 ..< array.count
{
msg_stat.append(oldMsg(is_checked: false))
}
collection_view.delegate = self
collection_view.dataSource = self
}catch{
print(error)
}
}
func collectionView(_ collectionView: UICollectionView,
numberOfItemsInSection section: Int) -> Int {
return array.count
}
func collectionView(_ collectionView: UICollectionView, cellForItemAt
indexPath: IndexPath) -> UICollectionViewCell {
let cell = collectionView.dequeueReusableCell(withReuseIdentifier:
"AdvisoryCollectionViewCell", for: indexPath) as!
AdvisoryCollectionViewCell
cell.msg_label.text = struct_array[indexPath.item].advisory
cell.date_label.text = struct_array[indexPath.item].date
let imagee = UIImage.init(named: "rsz_tick")
cell.check_image.image = imagee
cell.check_image.isHidden = true
if( msg_stat[indexPath.row].is_checked == false){
cell.check_image.isHidden = true
}
else if(msg_stat[indexPath.row].is_checked == true)
{
cell.check_image.isHidden = false
}
else{
}
return cell
}
func longpress(gestureRecognizer: UIGestureRecognizer)
{
let righbarButton = UIBarButtonItem(image: UIImage(named:
"rsz_delete")?.withRenderingMode(.alwaysOriginal), style:
UIBarButtonItemStyle.plain, target: self, action:
#selector(myRightTapped(sender:)))
self.navigationItem.rightBarButtonItem = righbarButton
let longpress = gestureRecognizer as! UILongPressGestureRecognizer
let state = longpress.state
let locationInview = longpress.location(in: collection_view)
var indexpath=collection_view.indexPathForItem(at: locationInview)
if(gestureRecognizer.state == UIGestureRecognizerState.began)
{
let cell = collection_view.cellForItem(at: indexpath!) as!
AdvisoryCollectionViewCell
cell.check_image.isHidden = false
msg_stat[(indexpath?.row)!].is_checked = true
ss.append((indexpath?.item)!)
print("index of deleting = \(indexpath?.item)")
msg_count_array.append((indexpath?.item)!)
msg_array.append(struct_array[(indexpath?.item)!].advisory)
selected_date_array.append(struct_array[(indexpath?.item)!].date)
selected_srno_array.append(struct_array[(indexpath?.item)!].srno)
}
}
func collectionView(_ collectionView: UICollectionView, didSelectItemAt
indexPath: IndexPath) {
let cell = collection_view.cellForItem(at: indexPath)
as!AdvisoryCollectionViewCell
if(!(ss.isEmpty)){
cell.check_image.isHidden = !cell.check_image.isHidden
if(cell.check_image.isHidden == true)
{
msg_stat[indexPath.row].is_checked = false
print("why removing.....")
if(!(msg_count_array.isEmpty)){
msg_count_array.remove(at: (indexPath.item))}
if(!(msg_array.isEmpty)){
msg_array.remove(at: (indexPath.item))
}
if(!(selected_srno_array.isEmpty))
{
selected_srno_array.remove(at: (indexPath.item))
}
if(!(selected_date_array.isEmpty))
{
selected_date_array.remove(at: (indexPath.item))
}
}
else{
msg_stat[indexPath.row].is_checked = true
msg_count_array.append((indexPath.item))
msg_array.append(array[(indexPath.item)])
selected_srno_array.append(struct_array[(indexPath.item)].srno)
}
}
}
func myRightTapped(sender:UIBarButtonItem!)
{
do{
for i in 0 ..< msg_count_array.count
{
struct_array.remove(at: i)
msg_stat.remove(at: i)
}
msg_count_array.removeAll()
for i in 0 ..< msg_array.count
{
var msg = msg_array[i]
var srno = selected_srno_array[i]
let
path=NSSearchPathForDirectoriesInDomains(.documentDirectory,.userDomainMask,
true).first!
let dbQueue = try DatabaseQueue(path: "\(path)/pest_messenger.sqlite")
try dbQueue.inDatabase { db in
try db.execute("DELETE FROM crop_insect_advisory_issued where srno='\
(srno)'")
}
}
msg_array.removeAll()
array.removeAll()
date_array.removeAll()
srno_array.removeAll()
// let dbQueue = try DatabaseQueue(path: "\(path)/p_messenger.sqlite")
try dbQueue?.inDatabase { db in
let rows = try Row.fetchCursor(db, "SELECT distinct brief_advisory,advisory_date,srno FROM crop_insect_advisory_issued where crop_code='\(crop_code)'")
while let row = try rows.next() {
let title: String = row.value(named: "brief_advisory")
let da:String=row.value(named:"advisory_date")
let srno:Int = row.value(named:"srno")
let date_f=DateFormatter()
date_f.dateFormat="yyyy-MM-dd"
let d=date_f.date(from: da)
date_f.dateFormat="dd-MM-yyyy"
let dd=date_f.string(from: d!)
array.append(title)
date_array.append(dd)
srno_array.append("\(srno)")
}
}
for i in 0 ..< array.count
{
struct_array.append(myObject(date:date_array[i],advisory:array[i],
status:"N",srno:srno_array[i]))
}
for i in 0 ..< array.count
{
msg_stat.append(oldMsg(is_checked: false))
}
collection_view.reloadData()
}
catch{
print(error)
}
}
}