Need Help Deleting Data From UITableView

I am trying to make my UITableView Editable but I'm having some开发者_运维百科 trouble with the code, specifically with the commitEditingStyle method. It is not working I think the method I have is only for plist and not for an array by itself.

#import "RoutineTableViewController.h"
#import "AlertPrompt.h"

@implementation RoutineTableViewController
@synthesize myArray;

- (void)dealloc
{
    [super dealloc];
}

- (void)didReceiveMemoryWarning
{
    [super didReceiveMemoryWarning];
}

#pragma mark - View lifecycle

- (void)viewDidLoad
{
    myArray = [[NSMutableArray alloc] init]; 
    myData = [[NSMutableArray arrayWithContentsOfFile:@"mydata"] retain]; 

    if (myData == nil)
    {
        myData = [NSMutableArray array];  
    }

    [super viewDidLoad];

    UIBarButtonItem * addButton = [[UIBarButtonItem alloc] initWithBarButtonSystemItem:UIBarButtonSystemItemAdd target:self action:@selector(showPrompt)];
    [self.navigationItem setLeftBarButtonItem:addButton];
    [addButton release];

    self.navigationItem.rightBarButtonItem = self.editButtonItem;
}

-(void)showPrompt
{
    AlertPrompt *prompt = [AlertPrompt alloc];
    prompt = [prompt initWithTitle:@"Add Workout Day" message:@"\n \n Please enter title for workout day" delegate:self cancelButtonTitle:@"Cancel" okButtonTitle:@"Add"];

    [prompt show];
    [prompt release];
}

- (void)alertView:(UIAlertView *)alertView willDismissWithButtonIndex:(NSInteger)buttonIndex
{
    if (buttonIndex != [alertView cancelButtonIndex])
    {
        NSString *entered = [(AlertPrompt *)alertView enteredText];
        NSLog([NSString stringWithFormat:@"%@", entered]);
        if(myData && entered)
        {
            [myArray addObject:entered];
            [tableView reloadData];
        }
    }
}

- (void)viewDidUnload
{
    [super viewDidUnload];
}

- (void)viewWillAppear:(BOOL)animated
{
    [super viewWillAppear:animated];
}

- (void)viewDidAppear:(BOOL)animated
{
    [super viewDidAppear:animated];
}

- (void)viewWillDisappear:(BOOL)animated
{
    [super viewWillDisappear:animated];
}

- (void)viewDidDisappear:(BOOL)animated
{
    [super viewDidDisappear:animated];
}

- (BOOL)shouldAutorotateToInterfaceOrientation:(UIInterfaceOrientation)interfaceOrientation
{
    // Return YES for supported orientations
    return (interfaceOrientation == UIInterfaceOrientationPortrait);
}

#pragma mark - Table view data source

- (NSInteger)numberOfSectionsInTableView:(UITableView *)tableView
{
    return 1;
}

- (NSInteger)tableView:(UITableView *)tableView numberOfRowsInSection:(NSInteger)section
{
    return [myArray count];
}

- (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] autorelease];
    }
    cell.textLabel.text = [self.myArray objectAtIndex:indexPath.row];

    return cell;
}


/*
// Override to support conditional editing of the table view.
- (BOOL)tableView:(UITableView *)tableView canEditRowAtIndexPath:(NSIndexPath *)indexPath
{
    // Return NO if you do not want the specified item to be editable.
    return YES;
}
*/


// Override to support editing the table view.
- (void)tableView:(UITableView *)tableView commitEditingStyle:(UITableViewCellEditingStyle)editingStyle forRowAtIndexPath:(NSIndexPath *)indexPath
{

    NSUInteger row = [indexPath row];
    [self.list removeObjectAtIndex:row];
    [tableView deleteRowsAtIndexPaths:[myArray arrayWithObject:indexPath] withRowAnimation:UITableViewRowAnimationFade];

As prevoulsy ansewered; self.list has to be Mutable.

The next thing you need to do is "warn" the tableView about the updates.

So you would do it like this:

- (void)tableView:(UITableView *)tableView commitEditingStyle:(UITableViewCellEditingStyle)editingStyle forRowAtIndexPath:(NSIndexPath *)indexPath
{

    NSUInteger row = [indexPath row];
    [self.list removeObjectAtIndex:row];
    //Notice we "warn" the tableView
    [tableView beginUpdates];
    [tableView deleteRowsAtIndexPaths:[NSMutableArray arrayWithObject:indexPath] withRowAnimation:UITableViewRowAnimationFade];
    //We also tell the table the updates are done so it can do the proper animations
    [tableView endUpdates];
}

Remember you first change the model and then update the tableView with the add, reload and delete methods in between a beginUpdates and endUpdates.

What type is self.list? It needs to be an NSMutableArray for a call to 'removeObjectAtIndex' to be valid.

There is no .plist involved here, that's just the name of this NSMutableArray. Your sample code assumes you are declaring an NSMutableArray called list in your @interface...

@interface RoutineTableViewController : UIViewController {
    NSMutableArray *list; 
}
@property (nonatomic, retain) NSMutableArray *list;
@end

... and synthesizing it (and filling it with something) somewhere in your code.