Tableview scroll slow down due to Method call - ios

Question

In my tableview cell, there is a label for Description. The description text will be highlighted through Attributed Text in separate method. this method is call from cellforRowIndexPath & that's why tableview scroll is lagging a lot.
My code
- (UITableViewCell *)tableView:(UITableView *)tableView cellForRowAtIndexPath:(NSIndexPath *)indexPath
{
SearchVCCell *cell = (SearchVCCell *)[tableView dequeueReusableCellWithIdentifier:cellidentifier];
if (cell == nil)
{
NSArray *nib = [[NSBundle mainBundle] loadNibNamed:#"SearchVCCell" owner:self options:nil];
cell = [nib objectAtIndex:0];
cell.lbl_title.text=[NSString stringWithFormat:#"%#",[arrTitle objectAtIndex:indexPath.row]];
cell.lbl_disc.text=[NSString stringWithFormat:#"%#",[arrDescription objectAtIndex:indexPath.row]];
cell.lbl_page.text=[NSString stringWithFormat:#"Page: %d",[[arrPageNumber objectAtIndex:indexPath.row]intValue]];
int p= [self highlightText:_search_bar.text :cell.lbl_disc]; //Method Call
cell.lbl_count.text=[NSString stringWithFormat:#"%d",p];
}
return cell;
}
HightText Method:
-(int) highlightText :(NSString *)srcTxt :(UILabel*)txtView {
int srcTxtLen = srcTxt.length;
int idx = 0,count=0;
while (idx<(txtView.text.length-srcTxtLen)) {
NSRange srcRange = NSMakeRange(idx, srcTxtLen);
if ([[txtView.text substringWithRange:srcRange] isEqualToString:srcTxt]) {
NSMutableAttributedString *tmpAttrTxt = [[NSMutableAttributedString alloc] initWithAttributedString:txtView.attributedText];
[tmpAttrTxt addAttribute:NSBackgroundColorAttributeName value:[UIColor yellowColor] range:srcRange];
txtView.attributedText = tmpAttrTxt;
idx += srcTxtLen;
count++;
} else {
idx++;
}
}
return count;
}
Help me to solve, Thanks in advance

Answer 1

you can replace your method call with this
NSMutableAttributedString * string = [[NSMutableAttributedString alloc]initWithString:cell.lbl_disc.text];
NSRange range=[cell.lbl_disc.text rangeOfString:_search_bar.text];
[string addAttribute:NSForegroundColorAttributeName value:[UIColor yellowColor] range:range];
[self.textToSpeak setAttributedText:string];

Answer 2

use this method:
- (NSMutableAttributedString*) setColor:(UIColor*)color forWord:(NSString*)word inText:(NSMutableAttributedString*)string {
NSUInteger count = 0, length = [string length];
NSRange range = NSMakeRange(0, length);
while(range.location != NSNotFound)
{
range = [[string string] rangeOfString:word options:0 range:range];
if(range.location != NSNotFound) {
[string setTextColor:color range:NSMakeRange(range.location, [word length])];
range = NSMakeRange(range.location + range.length, length - (range.location + range.length));
count++;
}
}
return string;
}
and in your tableview cell call this
cell.lbl_disc.text= [self setColor:[UIColor yellowColor] forWord:_search_bar.text inText:[[NSMutableAttributedString alloc] initWithAttributedString:[NSString stringWithFormat:#"%#",[arrDescription objectAtIndex:indexPath.row]]]];