無限テーブル

.h

# import <UIKit/UIKit.h>

@interface InfiniteTableView : UITableView
<UITableViewDataSource>
@end

.m

# import "InfiniteTableView.h"

@interface InfiniteTableView() {
	int mTotalCellsVisible;
}
@end

@implementation InfiniteTableView

- (id)initWithFrame:(CGRect)frame {
    self = [super initWithFrame:frame];
    if (self) {
		self.showsVerticalScrollIndicator = NO;
    }
    return self;
}

-(void)resetContentOffsetIfNeeded {

	NSArray *indexpaths = [self indexPathsForVisibleRows];
    int totalVisibleCells = indexpaths.count;
    if( mTotalCellsVisible > totalVisibleCells )
    {
        //we dont have enough content to generate scroll
        return;
    }
    CGPoint contentOffset  = self.contentOffset;
    
    //check the top condition
    //check if the scroll view reached its top.. if so.. move it to center.. remember center is the start of the data repeating for 2nd time.
    if( contentOffset.y <= 0.0) {
        contentOffset.y = self.contentSize.height / 3.0f;
    }
    else if( contentOffset.y >= ( self.contentSize.height - self.bounds.size.height) )//scrollview content offset reached bottom minus the height of the tableview
    {
        //this scenario is same as the data repeating for 2nd time minus the height of the table view
        contentOffset.y = self.contentSize.height/3.0f- self.bounds.size.height;
    }
    [self setContentOffset: contentOffset];
}

- (void)layoutSubviews
{
    [super layoutSubviews];
	mTotalCellsVisible = self.frame.size.height / self.rowHeight;
	[self resetContentOffsetIfNeeded];
}

-(NSInteger)numberOfSectionsInTableView: (UITableView *)tableView {return 1;}
-(NSInteger)tableView:(UITableView *)tableView numberOfRowsInSection:(NSInteger)section {return 10 * 3;}

-(UITableViewCell *)tableView: (UITableView *)tableView cellForRowAtIndexPath:(NSIndexPath *)indexPath {
	NSString *cellid = @"cell";
    UITableViewCell *cell = [tableView dequeueReusableCellWithIdentifier:cellid];
	if (cell == nil) {
		cell = [[UITableViewCell alloc] initWithStyle:UITableViewCellStyleDefault reuseIdentifier:cellid];
	}
	cell.textLabel.text = [NSString stringWithFormat:@"cell: %d", indexPath.row % 10];
	return cell;
}

@end