NSTimer wont stop [duplicate] - xcode

Question

This question already has answers here:
Closed 10 years ago.
Possible Duplicate:
NSTimer doesn't stop
I am having a hard time stopping my timer, witch pings to my server.
I already searched for other answers here and on other places, but i can`t seem to find where i have gone wrong.
I decided to make an example code with the same idea, but, you click a button the timer starts, you click another the timer ends, and it worked the way it should. Please don't mind if i did something wrong (other than the timer part) i'm new in this. All i want to know is why won`t it stop..
Thanks in advance.
Connection.h
#import <Foundation/Foundation.h>
#interface Connection : NSObject
{
NSString *urlString;
NSURL *url;
NSMutableURLRequest *request;
NSURLConnection *connection;
NSURLResponse *response;
NSMutableData *receivedData;
NSData *responseData;
NSError *error;
NSTimer *timer;
}
#property (nonatomic, retain) NSTimer *timer;
-(BOOL)authenticateUser:(NSString *)userName Password:(NSString *)password;
-(BOOL)checkConnection;
-(void)ping:(NSTimer *)aTimer;
-(void)logout;
-(void)timerStart;
-(void)timerStop;
#end
Connection.m
#import "Connection.h"
#import "Parser.h"
#import "Reachability.h"
#import "TBXML.h"
#implementation Connection
#synthesize timer;
-(BOOL) authenticateUser:(NSString *)userName Password:(NSString *)password
{
BOOL success;
urlString = [[NSString alloc] initWithFormat:#"my/server/address/login"];
url =[[NSURL alloc] initWithString:urlString];
request = [NSURLRequest requestWithURL:url cachePolicy:NSURLRequestReloadIgnoringCacheData timeoutInterval:10];
error = [[NSError alloc] init];
responseData = [NSURLConnection sendSynchronousRequest:request returningResponse:&response error:&error];
[responseData retain];
NSString *tempString = [[NSString alloc] initWithData:responseData encoding:NSUTF8StringEncoding];
NSMutableDictionary *tempDict= [[NSMutableDictionary alloc] init];
if (request)
{
Parser *parser = [[Parser alloc] init];
tempDict = [parser readXMLString:tempString];
for (id key in tempDict)
{
NSLog(#"%# is %#",key,[tempDict objectForKey:key]);
}
if ([[tempDict objectForKey:#"login"] isEqualToString:#"true"] )
{
success = YES;
self.timerStart;
}
else
{
success = NO;
}
}
[urlString release];
[url release];
[error release];
[responseData release];
[tempString release];
return success;
}
-(void)logout
{
self.timerStop;
}
-(void)ping:(NSTimer *)aTimer;
{
urlString = [[NSString alloc] initWithFormat:#"my/server/address"];
url =[[NSURL alloc] initWithString:urlString];
request = [NSURLRequest requestWithURL:url cachePolicy:NSURLRequestReloadIgnoringCacheData timeoutInterval:10];
NSLog(#"ping");
[urlString release];
[url release];
}
-(BOOL)checkConnection
{
Reachability *reachability = [Reachability reachabilityWithHostName:#"http://my/server/address"];
NetworkStatus internetStatus = [reachability currentReachabilityStatus];
if ((internetStatus != ReachableViaWiFi) && (internetStatus != ReachableViaWWAN))
{
return NO;
}
else
{
return YES;
}
}
-(void)timerStart
{
self.timer = [NSTimer scheduledTimerWithTimeInterval:1 target:self selector:#selector(ping:) userInfo:nil repeats:YES];
}
-(void)timerStop
{
[self.timer invalidate];
self.timer = nil;
}
#end

Answer 1

In timerStart you just replace whatever is in the timer property. If you start a second timer without stopping the first one, it will run forever. So timerStart should first call timerStop before creating a new one (and should probably have a new name then as it would be silly to call timerStop from timerStart).

Answer 2

Use [self timerStop]; using dot syntax is ONLY for properties (and will generate a warning if you don't), not calling a method in the way you're doing it.
Edit: This won't fix your problem, but doing it the way you are is very bad coding practice

Answer 3

-(void)timerStart
{
[self.timer invalidate];
self.timer = [NSTimer scheduledTimerWithTimeInterval:1 target:self selector:#selector(ping:) userInfo:nil repeats:YES];
}