Save random number generated in Table View - ios

Question

My app is currently generating random numbers (see code below). What I want is to save that number once the user hits the "Save" button and show it on a table view.
#import "ViewController.h"
#interface ViewController ()
#end
#implementation ViewController
- (void)viewDidLoad
{
[super viewDidLoad];
// Do any additional setup after loading the view, typically from a nib.
[self.clickyButton setTitle:#"Generate" forState:UIControlStateNormal];
}
- (void)didReceiveMemoryWarning
{
[super didReceiveMemoryWarning];
// Dispose of any resources that can be recreated.
}
- (IBAction)handleButtonClick:(id)sender {
// Generates numbers 1 to 49, without creating duplicate numbers.
NSMutableSet * numberSet = [NSMutableSet setWithCapacity:5];
while ([numberSet count] < 7 ) {
NSNumber * randomNumber = [NSNumber numberWithInt:(arc4random() % 49 + 1)];
[numberSet addObject:randomNumber];
}
NSArray * numbers = [numberSet allObjects];
self.n1.text = [NSString stringWithFormat:#"%#", [numbers objectAtIndex:0]];
self.n2.text = [NSString stringWithFormat:#"%#", [numbers objectAtIndex:2]];
self.n3.text = [NSString stringWithFormat:#"%#", [numbers objectAtIndex:3]];
self.n4.text = [NSString stringWithFormat:#"%#", [numbers objectAtIndex:4]];
self.n5.text = [NSString stringWithFormat:#"%#", [numbers objectAtIndex:5]];
self.n6.text = [NSString stringWithFormat:#"%#", [numbers objectAtIndex:6]];
}
#end
Please explain me how I can save it on a table view. xcode beginner.

Answer 1

You should create a variable that's accessible within the scope of the whole class rather than just the specific -handleButtonClick: method, and then add the generated numbers to that variable - an array, set, etc...
From there, you can implement the table view to read the values from the variable via var[indexPath.row] (assuming it's an array), and display it. You will need to call [tableView reloadData]; once the array has been filled with objects to make sure that the tableview displays the data.

Answer 2

create a NSMutableArray for UITableViewDataSource and cache the number.
when a number created by the user,add this number into NSMutableArray.
reload UITableView and show all numbers.

Answer 3

If you use only one number you should think about displaying it in another UI element, preferably a UILabel I would say.
If you want to use a UITableView you will either have to create it with static cells (e.g. in a Storyboard) or configure the data source and delegate object for it (which doesn't really seem what you want right now, unless maybe if you wanted to display multiple random numbers in a list...)

Answer 4

Before anything you should make the array numbers as a variable. In that way it is much easier than creating n1,n2,n3,.... I will show you how to solve your problem based on an existing numbers NSArray variable defined.
You need to implement the UITableView delegates in your header file. So let's suppose this is your header file after implementing the delegates:
#import <UIKit/UIKit.h>
#interface ViewController : UIViewController <UITableViewDataSource, UITableViewDelegate>
#property (weak, nonatomic) IBOutlet UITableView *tableView;
#end
Then take your tableview (IBOutlet or programatically) and set the dataSource and delegate in the implementation file. You should do this in the viewDidLoad: method like this:
[_tableView setDelegate:self];
[_tableView setDataSource:self];
After you have done this you need to implement the delegate methods for the UITableView. This ones:
This method will tell the Table View how many rows it needs to show. In your case is the size of the NSArray called numbers:
- (NSInteger)tableView:(UITableView *)tableView numberOfRowsInSection:(NSInteger)section
{
return numbers.count;
}
This method will tell the Table View what to show on each cell (DON'T FORGET TO ASSING THE CELL IDENTIFIER OF THE CELL IN THE INTERFACE BUILDER TO "Cell")
- (UITableViewCell *)tableView:(UITableView *)tableView cellForRowAtIndexPath:(NSIndexPath *)indexPath
{
static NSString *cellIdentifier = #"Cell";
UITableViewCell *cell = [tableView dequeueReusableCellWithIdentifier:cellIdentifier];
if (cell == nil) {
cell = [[UITableViewCell alloc] initWithStyle:UITableViewCellStyleDefault reuseIdentifier:cellIdentifier];
}
cell.textLabel.text = [numbers objectAtIndex:indexPath.row];
return cell;
}
Use this method if you want to do something when the user touches a cell in the table view:
- (void)tableView:(UITableView *)tableView didSelectRowAtIndexPath:(NSIndexPath *)indexPath {
}
Finally to add numbers to the list as the user touches the button you just need to add these lines of code to your method triggered by the button:
- (IBAction)handleButtonClick:(id)sender {
// Generates numbers 1 to 49, without creating duplicate numbers.
NSMutableSet * numberSet = [NSMutableSet setWithCapacity:5];
while ([numberSet count] < 7 ) {
NSNumber * randomNumber = [NSNumber numberWithInt:(arc4random() % 49 + 1)];
[numberSet addObject:randomNumber];
}
//In case you want to delete previous numbers
[numbers removeAllObjects];
numbers = [numberSet allObjects];
[_tableView reloadData];
}