How to implement Ticker in my application in iphone - iphone

Question

I just want in my application a ticker,
i have no idea to implement ticker please tell me.
Thanks

Answer 1

Everything you need to do this is in the SDK, no need to customize at all. I haven't checked this, but you can try the following:
#import <UIKit/UIKit.h>
#interface TickerScrollView : UIScrollView {
UILabel *textLabel;
}
- (void)displayText:(NSString *)string;
- (void)clearTicker;
#property (nonatomic, retain, readwrite) UILabel *textLabel;
#end
////
#import "TickerScrollView.h"
#interface TickerScrollView()
- (void)initialiseTextLabel;
- (void)clearTicker;
- (void)beginAnimation;
#end
#implementation TickerScrollView
- (id)initWithFrame:(CGRect)frame {
if ((self = [super initWithFrame:frame])) {
// Initialization code
[self setFrame: frame];
[self setBounces: NO];
[self setUserInteractionEnabled:NO];
[self setShowsVerticalScrollIndicator:NO];
[self setShowsHorizontalScrollIndicator:NO];
[self initialiseTextLabel];
}
return self;
}
- (void)initialiseTextLabel {
textLabel = [[[UILabel alloc] initWithFrame:self.bounds] autorelease];
[textLabel setTextAlignment:UITextAlignmentLeft];
[textLabel setNumberOfLines:1];
[textLabel sizeToFit];
[self addSubview:textLabel];
[self sendSubviewToBack:textLabel];
[self setScrollEnabled:YES];
}
- (void)displayText:(NSString *)string {
[self clearTicker];
[textLabel setText:string];
[textLabel sizeToFit];
[self setContentSize:textLabel.frame.size];
[self beginAnimation];
}
- (void)clearTicker {
[textLabel setText:#""];
[textLabel sizeToFit];
CGPoint origin = CGPointMake(0, 0);
[self setContentOffset:origin];
}
- (void)beginAnimation {
CGFloat text_width = textLabel.frame.size.width;
CGFloat display_width = self.frame.size.width;
if ( text_width > display_width ) {
CGPoint origin = CGPointMake(0, 0);
[self setContentOffset:origin];
CGPoint terminal_origin = CGPointMake(textLabel.frame.size.width - self.frame.size.width, textLabel.frame.origin.y);
float duration = (text_width - display_width)/50;
[UIView beginAnimations:nil context:NULL];
[UIView setAnimationCurve:UIViewAnimationCurveLinear];
[UIView setAnimationDelay:1.0];
[UIView setAnimationDuration:duration];
[self setContentOffset:terminal_origin];
[UIView commitAnimations];
}
}
/*
// Only override drawRect: if you perform custom drawing.
// An empty implementation adversely affects performance during animation.
- (void)drawRect:(CGRect)rect {
// Drawing code
}
*/
- (void)dealloc {
[textLabel release];
[super dealloc];
}
#synthesize textLabel;
#end

Answer 2

Assuming by "Ticker" you mean a horizontally scrolling text:
A ticker is basically just a text string that is moving by having its x coordinate changed continuously. Check this simple tutorial on how to display a label:
http://knol.google.com/k/iphone-sdk-helloworld
Then later you can animate it by using an NSTimer to call a method updating the labels x coordinate continuously.