Xcode: saving data issue with NSUserDefaults and TableView - iphone

Question

I am trying to save data via NSUserDefaults and view it on the tableView but nothing happen after I click on the save button, after I stop and run the application again the data that I saved it I can see it which every time it overwrite on the old data. Am I doing something wrong? Or should I use something different from NSUserDefaults?
Thanks in advance.
-(IBAction)save{
NSUserDefaults *add1 = [NSUserDefaults standardUserDefaults];
[add1 setObject:txt1.text forKey:#"txt1"];
[add1 synchronize];
}
- (void)viewDidLoad
{
[super viewDidLoad];
NSUserDefaults *prefs = [NSUserDefaults standardUserDefaults];
self.dataArray = [NSArray arrayWithObjects:[prefs objectForKey:#"txt1"], nil];
}
- (NSInteger)numberOfSectionsInTableView:(UITableView *)tableView
{
return 1;
}
- (NSInteger)tableView:(UITableView *)tableView numberOfRowsInSection:(NSInteger)section
{
return [dataArray count];
}
- (UITableViewCell *)tableView:(UITableView *)tableView cellForRowAtIndexPath:(NSIndexPath *)indexPath
{
NSString *string = [dataArray objectAtIndex:indexPath.row];
static NSString *CellIdentifier = #"Cell";
UITableViewCell *cell = [tableView dequeueReusableCellWithIdentifier:CellIdentifier];
if(cell==nil)
{
cell = [[[UITableViewCell alloc] initWithStyle:UITableViewCellStyleDefault reuseIdentifier:CellIdentifier] autorelease];
}
cell.textLabel.text=string;
return cell;
}

Answer 1

There are two issues in your code:
You are not refreshing the tableview. You can do this by calling:
[self.tableView reloadData]; // Or whatever property is pointing to your tableview
Every time you save a value, you save it under the same key (txt1) and that's why you override every time. If you want a list of items (an array) and to append the item into this array, you could do something like this:
NSMutableArray *myList = [[[NSUserDefaults standardUserDefaults] valueForKey:#"myTxtList"] mutableCopy];
[myList addObject:txt1.text];
[[NSUserDefaults standardUserDefaults] setObject:[NSArray arrayWithArray:myList] forKey:#"myTxtList"];
[add1 synchronize];
self.dataArray = myList;
[self.tableView reloadData];
P.S. Of course you need to set your dataArray accordingly in your viewDidLoad:
self.dataArray = [[NSUserDefaults standardUserDefaults] objectForKey:#"myTxtList"];

Answer 2

As A for Alpha said try that & in addition I am having doubt in your save method definition too. Just try changing it to the following
-(IBAction)save:(id)sender{
NSUserDefaults *add1 = [NSUserDefaults standardUserDefaults];
[add1 setObject:txt1.text forKey:#"txt1"];
[add1 synchronize];
[tableView reloadData];
}
This may work out for u.

Answer 3

I guess you need to call [yourTableView reloadData] after saving the data in userDefaults. This should solve your problem.