正确地从UITableView中删除一个项目

Question

有没有人可以请解释一下如何正确实施tableView:commitEditingStyle:forRowAtIndexPath:方法，以便我可以正确删除支持数组中的项目并仅显示尚未删除的项目？

这是我到目前为止有：

@interface ViewController : UIViewController <UITableViewDelegate,UITableViewDataSource> 
{ 
    IBOutlet UITableView *tableView; 

    NSArray *allItems; 
    NSMutableArray *displayItems; 
} 

@end 

@implementation ViewController 

- (void)viewDidLoad 
{ 
    [super viewDidLoad]; 
    allItems = [[NSArray alloc] initWithObjects:@"One",@"Two",@"Three",@"Four",@"Five",@"Six",@"Seven", nil]; 
    displayItems = [[NSMutableArray alloc] initWithArray:allItems]; 
} 

-(UITableViewCell*) tableView:(UITableView *)aTableView cellForRowAtIndexPath:(NSIndexPath *)indexPath{ 
    UITableViewCell *cell = [tableView dequeueReusableCellWithIdentifier:@"cell"]; 
    if (!cell) { 
     cell = [[UITableViewCell alloc] initWithStyle:UITableViewCellStyleDefault reuseIdentifier:@"cell"]; 
    } 
    cell.textLabel.text = [displayItems objectAtIndex:indexPath.row]; 
    return cell; 
} 

@end 

Answer 1

试试这个：

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

    if (editingStyle == UITableViewCellEditingStyleDelete) { 
     // Delete the row from the data source. 
     [tableView deleteRowsAtIndexPaths:[NSArray arrayWithObject:indexPath] withRowAnimation:UITableViewRowAnimationFade]; 
     if(!deletedIndices) deletedIndices = [[NSMutableIndexSet alloc] initWithIndex:indexPath.row]; 
     else [deletedIndices addIndex:indexPath.row]; 
    } 
    else if (editingStyle == UITableViewCellEditingStyleInsert) { 
     // Create a new instance of the appropriate class, insert it into the array, and add a new row to the table view. 
    } 
} 

-(IBAction)editingDidComplete:(id)sender 
{ 

    // remove the objects from display array 
    [valueArray removeObjectsAtIndexes:deletedIndices]; 
    // Reload tableView if needed 
    [mainTableView reloadData]; 
    [mainTableView setEditing:NO]; 
} 

Answer 2

实现你tableView:commitEditingStyle:forRowAtIndexPath:如下：

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

    if (editingStyle == UITableViewCellEditingStyleDelete) { 

     // remove the object from display array 
     [displayItems removeObjectAtIndex:indexPath.row]; 

     // Delete the row from the data source. 
     [aTableView deleteRowsAtIndexPaths:[NSArray arrayWithObject:indexPath] withRowAnimation:UITableViewRowAnimationFade]; 

    } 
    else if (editingStyle == UITableViewCellEditingStyleInsert) { 
     // Create a new instance of the appropriate class, insert it into the array, and add a new row to the table view. 
    } 
}