Load Data On Uitableview scroll [duplicate] - iphone

Question

This question already has answers here:
making a "load more" button in uitableviewcell?
(4 answers)
Closed 9 years ago.
I have 2000 records and i have to display only 15 records in UITableView, When User Scroll UITableView , More 15 records shold be load in table. How should I do it?

Answer 1

I think the Answer is : - (void)scrollViewDidScroll:(UIScrollView *)scrollView
- (void)scrollViewDidScroll:(UIScrollView *)scrollView
{
CGPoint offset = scrollView.contentOffset;
CGRect bounds = scrollView.bounds;
CGSize size = scrollView.contentSize;
UIEdgeInsets inset = scrollView.contentInset;
float y = offset.y + bounds.size.height - inset.bottom;
float h = size.height;
float reload_distance = 15;
if(y > h + reload_distance)
{
//Call the Method to load More Data...
}
}
Hope it will be helpful...!!!

Answer 2

You have to check the UIScrollView contentOffset for that (UITableView is built on UIScrollView). So, add this, to your UITableViewDelegate class:
- (void)scrollViewDidScroll:(UIScrollView *)scrollView {
// when reaching bottom, load more
float offs = (scrollView.contentOffset.y+scrollView.bounds.size.height);
float val = (scrollView.contentSize.height);
if (offs==val)
{
//add more data on your data array
}
}
in order to add more cells to your table when user reaches bottom of your table view.

Answer 3

You can use two delegate methods of UIScrollView. As UITableView comes in hierachy of UIScrollView you'll get control in this delegate methods of UIScrollView.
- (void)scrollViewDidScroll:(UIScrollView *)scrollView
{
NSLog(#"TableView scrolling");
}
- (void)scrollViewWillBeginDragging:(UIScrollView *)scrollView
{
NSLog(#"TableView Started scrolling");
}
Try above two methods. And choose the one appropriate for you. First see how NSLog are coming when you start scrolling your UITableVIew. And then write your code inside them.

Answer 4

By Default numberOfItemsToDisplay = 15;
- (NSInteger)numberOfSectionsInTableView:(UITableView *)tableView
{
if (numberOfItemsToDisplay >= [self.yourArray count])
{
numberOfItemsToDisplay = [self.yourArray count];
return 1;
}
return 2;
}
- (NSInteger)tableView:(UITableView *)tableView numberOfRowsInSection:(NSInteger)section
{
if (section == 0)
{
return numberOfItemsToDisplay;
}
else
{
return 1;
}
}
- (UITableViewCell *)tableView:(UITableView *)tableView cellForRowAtIndexPath:(NSIndexPath *)indexPath
{
if (indexPath.section == 0)
{
static NSString *CellIdentifier = #"YourCustomCell";
YourCustomCell *objYourCustomCell = [tableView dequeueReusableCellWithIdentifier:CellIdentifier];
if (objYourCustomCell == nil)
{
NSArray *topLevelObjects = [[NSBundle mainBundle] loadNibNamed:#"YourCustomCell" owner:self options:nil];
for(id currentObject in topLevelObjects)
{
if ([currentObject isKindOfClass:[YourCustomCell class]])
{
objYourCustomCell = (AlertsCustomCell *) currentObject;
break;
}
}
}
objYourCustomCell.lbl.text = [[self.yourArray objectAtIndex:indexPath.row]valueForKey:#"vName"];
return objYourCustomCell;
}
else
{
static NSString *CellIdentifier = #"Cell";
UITableViewCell *cell = [tableView dequeueReusableCellWithIdentifier:CellIdentifier];
if (cell == nil)
{
cell=[[UITableViewCell alloc] initWithStyle:UITableViewCellStyleDefault reuseIdentifier:CellIdentifier];
[cell.contentView addSubview:[self loadMoreViewForTable:self.view]];
}
return cell;
}
}
- (void)tableView:(UITableView *)tableView didSelectRowAtIndexPath:(NSIndexPath *)indexPath
{
[self.tblAlertsList deselectRowAtIndexPath:indexPath animated:YES];
if (indexPath.section == 1)
{
numberOfItemsToDisplay = [self loadMore:numberOfItemsToDisplay arrayTemp:self.yourArray tblView:self.tblAlertsList];
[self.tblAlertsList endUpdates];
}else
{
// action if it is not LoadMore
}
}
+ (NSInteger)loadMore : (NSInteger)numberOfItemsToDisplay arrayTemp:(NSMutableArray*)aryItems tblView:(UITableView*)tblList
{
int count =0;
NSUInteger i, totalNumberOfItems = [aryItems count];
NSUInteger newNumberOfItemsToDisplay = MIN(totalNumberOfItems, numberOfItemsToDisplay + kNumberOfItemsToAdd);
NSMutableArray *indexPaths = [[NSMutableArray alloc] init];
for (i=numberOfItemsToDisplay; i<newNumberOfItemsToDisplay; i++)
{
count++;
[indexPaths addObject:[NSIndexPath indexPathForRow:i inSection:0]];
}
numberOfItemsToDisplay = newNumberOfItemsToDisplay;
[tblList beginUpdates];
[tblList insertRowsAtIndexPaths:indexPaths withRowAnimation:UITableViewRowAnimationLeft];
if (numberOfItemsToDisplay == totalNumberOfItems) {
[tblList deleteSections:[NSIndexSet indexSetWithIndex:1] withRowAnimation:UITableViewRowAnimationLeft];
}
NSIndexPath *scrollPointIndexPath;
if (newNumberOfItemsToDisplay < totalNumberOfItems)
{
scrollPointIndexPath = [NSIndexPath indexPathForRow:numberOfItemsToDisplay-kNumberOfItemsToAdd inSection:0];
}
else
{
scrollPointIndexPath = [NSIndexPath indexPathForRow:i-count inSection:0];
}
dispatch_after(dispatch_time(DISPATCH_TIME_NOW, 100000000), dispatch_get_main_queue(), ^(void){
[tblList scrollToRowAtIndexPath:scrollPointIndexPath atScrollPosition:UITableViewScrollPositionNone animated:YES];
});
return numberOfItemsToDisplay;
}
I have to take custom cell to use this method? I have only taken UItableview

Answer 5

Try this:
http://www.cocoacontrols.com/controls/stableviewcontroller
use this two methods
//for refresh
- (void) addItemsOnTop {
//[self getLoginFollowingUserVideosCall];
[self refreshCompleted];
}
//for load more
- (void) addItemsOnBottom {
//[self getLoginFollowingUserVideosCall];
[self loadMoreCompleted];
}

Answer 6

What you have to do is load the tableview data lazily. Like load data for the tableview cell that are current visible & not all of the data at a time.