UITableView的排序与删除

UITableView有一个强大的编辑模式(editing mode),在编辑模式中可实现删除，插入，多选，排序等功能。使用的方法多很简单。以下介绍删除和排序功能：

首先查看SDK提供的API：

// Individual rows can opt out of having the -editing property set for them. If not implemented, all rows are assumed to be editable.
- (BOOL)tableView:(UITableView *)tableView canEditRowAtIndexPath:(NSIndexPath *)indexPath

// Moving/reordering
// Allows the reorder accessory view to optionally be shown for a particular row. By default, the reorder control will be shown only if the datasource implements -tableView:moveRowAtIndexPath:toIndexPath:

- (BOOL)tableView:(UITableView *)tableView canMoveRowAtIndexPath:(NSIndexPath *)indexPath
// After a row has the minus or plus button invoked (based on the UITableViewCellEditingStyle for the cell), the dataSource must commit the change
- (void)tableView:(UITableView *)tableView commitEditingStyle:(UITableViewCellEditingStyle)editingStyle forRowAtIndexPath:(NSIndexPath *)indexPat

 // Data manipulation - reorder / moving support
- (void)tableView:(UITableView *)tableView moveRowAtIndexPath:(NSIndexPath *)sourceIndexPath toIndexPath:(NSIndexPath *)destinationIndexPath

创建UITableView后简单的实现以上4个代理就可以实现删除和排序的功能。当然，你必须实现 UItableViewDataSource 穿件Cell的两个代理。以下是完整代码：

@interface ViewController () <UITableViewDataSource, UITableViewDelegate>
{
    UITableView *_tableView;
}
@end

@implementation ViewController

- (void)dealloc
{
    _tableView.delegate = nil;
    _tableView.dataSource = nil;
    [_tableView release],_tableView = nil;

    [super dealloc];
}

- (void)viewDidLoad
{
    [super viewDidLoad];
    
    UIBarButtonItem *navItem = [[UIBarButtonItem alloc]initWithTitle:@"Edit" style:UIBarButtonSystemItemEdit target:self action:@selector(editBUttonOnClicked)];
    self.navigationItem.rightBarButtonItem = navItem;
　　[navItem release];
    
    _tableView = [[UITableView alloc]initWithFrame:CGRectMake(0, 0, self.view.frame.size.width, self.view.frame.size.height - 44) style:UITableViewStylePlain];
    _tableView.delegate = self;
    _tableView.dataSource = self;
    [self.view addSubview:_tableView];
    
}

- (void)editBUttonOnClicked
{
    [_tableView setEditing:!_tableView.editing animated:YES];
    
    if (!_tableView.editing) {
        UIBarButtonItem *barButtonItem = self.navigationItem.rightBarButtonItem;
        barButtonItem.title = @"Edit";
    }else {
        UIBarButtonItem *barButtonItem = self.navigationItem.rightBarButtonItem;
        barButtonItem.title = @"Done";
    }
}
    
#pragma mark - UItableViewDataSource

- (NSInteger)tableView:(UITableView *)tableView numberOfRowsInSection:(NSInteger)section
{
    return 10;
}

- (UITableViewCell *)tableView:(UITableView *)tableView cellForRowAtIndexPath:(NSIndexPath *)indexPath
{
    static NSString *cellIdentifity = @"cellIdentifity";
    UITableViewCell *cell = [tableView dequeueReusableCellWithIdentifier:cellIdentifity];
    if (!cell) {
        cell = [[[UITableViewCell alloc]initWithStyle:UITableViewCellStyleDefault reuseIdentifier:cellIdentifity]autorelease];
    }
    
    cell.textLabel.text = [NSString stringWithFormat:@"%d",indexPath.row];
    return cell;
}

// Individual rows can opt out of having the -editing property set for them. If not implemented, all rows are assumed to be editable.
- (BOOL)tableView:(UITableView *)tableView canEditRowAtIndexPath:(NSIndexPath *)indexPath
{
    return YES;
}

// Moving/reordering

// Allows the reorder accessory view to optionally be shown for a particular row. By default, the reorder control will be shown only if the datasource implements -tableView:moveRowAtIndexPath:toIndexPath:
- (BOOL)tableView:(UITableView *)tableView canMoveRowAtIndexPath:(NSIndexPath *)indexPath
{
    return YES;
}

// After a row has the minus or plus button invoked (based on the UITableViewCellEditingStyle for the cell), the dataSource must commit the change
- (void)tableView:(UITableView *)tableView commitEditingStyle:(UITableViewCellEditingStyle)editingStyle forRowAtIndexPath:(NSIndexPath *)indexPat
{
    
}

// Data manipulation - reorder / moving support
//
- (void)tableView:(UITableView *)tableView moveRowAtIndexPath:(NSIndexPath *)sourceIndexPath toIndexPath:(NSIndexPath *)destinationIndexPath
{
　　//修改对应的数据源

　　//    id object=[[dataSource objectAtIndex:[fromIndexPath row]] retain];
　　//    [dataSource removeObjectAtIndex:[fromIndexPath row]]; 
　　//    [dataSource insertObject:object atIndex:[toIndexPath row]]; 
　　//    [object release]; 
}

说明：

1.必须实现 moveRowAtIndexPath 这个代理，才会出现可以拖拽的按钮；更新相关的NSArray数据才可以成功改变数据，

commitEditingStyle方法中需要reload数据。

2.根据需要设置cell是否支持排序和删除功能。