UITableView is not scrolling down - ios

Question

I created an ios app in which i have a table with dynamic cell generation. When i try to scroll down to the table. It returns to the top of the table. My code as follows:
-(CGFloat)tableView:(UITableView *)tableView heightForRowAtIndexPath:(NSIndexPath *)indexPath
{
if(!self.customCell){
self.customCell = [self.tableView dequeueReusableCellWithIdentifier:#"CustomCell"];
}
//Cell configuration
int quoteIndex = indexPath.row % [vendor count];
self.customCell.description.text = message[quoteIndex];
//Cell Layout
[self.customCell.description sizeToFit];
//Height of cell
float height = (CGRectGetMaxY(self.customCell.description.frame) +5);
return height + 1;
}
Here the cellForRowAtIndexPath:
-(UITableViewCell *)tableView:(UITableView *)tableView cellForRowAtIndexPath:(NSIndexPath *)indexPath
{
CustomTableViewCell *cell = [self.tableView dequeueReusableCellWithIdentifier:#"CustomCell"];
const char *dbpath = [_databasePath UTF8String];
sqlite3_stmt *statement;
if (sqlite3_open(dbpath, &_beaconDB) == SQLITE_OK)
{
NSString *querySQL = [NSString stringWithFormat:
#"SELECT vendor_name, enter_message, enter_image, vendor_image, received_date, time_interval FROM beacons WHERE id=%#", [unique objectAtIndex:indexPath.row]];
const char *query_stmt = [querySQL UTF8String];
if (sqlite3_prepare_v2(_beaconDB,
query_stmt, -1, &statement, NULL) == SQLITE_OK)
{
if (sqlite3_step(statement) == SQLITE_ROW)
{
title = [[NSString alloc]
initWithUTF8String:
(const char *) sqlite3_column_text(
statement, 0)];
description = [[NSString alloc]
initWithUTF8String:(const char *)
sqlite3_column_text(statement, 1)];
NSString *fullImage = [[NSString alloc]
initWithUTF8String:(const char *)
sqlite3_column_text(statement, 2)];
[fullImg insertObject:fullImage atIndex:indexPath.row];
NSString *vendorImage = [[NSString alloc]
initWithUTF8String:(const char *)
sqlite3_column_text(statement, 3)];
[thumbnailImg insertObject:vendorImage atIndex:indexPath.row];
NSString *receivedDate = [[NSString alloc]
initWithUTF8String:(const char *)
sqlite3_column_text(statement, 4)];
NSString *timeInterval = [[NSString alloc] initWithUTF8String:(const char *) sqlite3_column_text(statement, 5)];
BeaconAdTime *beaconAdTime = [[BeaconAdTime alloc] init];
NSDate *updatedTime = [beaconAdTime updatedDateTime:receivedDate andInterval:[timeInterval intValue]];
int count = 0;
do
{
NSDateFormatter *dateFormatter = [[NSDateFormatter alloc] init];
[dateFormatter setDateFormat: #"MMM-dd hh:mm a"];
BeaconAdTime *beaconAdTime = [[BeaconAdTime alloc] init];
NSString *presentDateTime = [beaconAdTime presentDateTime];
NSDate *presentDateConvert = [dateFormatter dateFromString:presentDateTime];
count++;
if([updatedTime compare:presentDateConvert] == NSOrderedAscending || count == 1)
{
cell.title.text = title;
cell.description.text = description;
cell.receivedDate.text = receivedDate;
NSString *imgURL = fullImg[indexPath.row];
NSURL *imageURL = [NSURL URLWithString:imgURL];
UIImage *image = nil;
image = [UIImage imageWithData:[NSData dataWithContentsOfURL: imageURL]];
cell.vendorImage.image = image;
NSUserDefaults *userDefauts = [NSUserDefaults standardUserDefaults];
[userDefauts setObject:fullImg forKey:#"fullImage"];
[userDefauts synchronize];
UILocalNotification *localNotif = [[UILocalNotification alloc] init];
NSData *data = [NSKeyedArchiver archivedDataWithRootObject:localNotif];
[[NSUserDefaults standardUserDefaults] setObject:data forKey:[NSString stringWithFormat:#"%d", indexPath.row]];
NSString *uid = [NSString stringWithFormat:#"%d", indexPath.row];
NSDictionary *infodict = [NSDictionary dictionaryWithObject:uid forKey:#"id"];
localNotif.userInfo = infodict;
NSDate *fireTime = [[NSDate date] addTimeInterval:0];
localNotif.fireDate = fireTime;
localNotif.alertBody = description;
[[UIApplication sharedApplication] scheduleLocalNotification:localNotif];
if(count>1)
{
break;
}
}
}
while (updatedTime!=nil);
}
sqlite3_finalize(statement);
}
sqlite3_close(_beaconDB);
}
// cell.title.text = vendor[indexPath.row];
//
// cell.vendorImage.image = [UIImage imageNamed:#"gg.jpg"];
return cell;
}
Thanks in advance.

Answer 1

You should not dequeue cells in height for row at index path. Also, self.customCell implies that you are working with just one cell. This is a very strange and unusual pattern.
Also, all those sqlite calls for each recycled cell is very inefficient. Instead, fetch the data you need into an array and work with that.
Also, avoid allocating formatters etc. in your cell method. Instead, use a static variable.