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"];