如何从表格中删除单元格

Question

我使用 asihttprequest 下载文件，但是当下载失败时，与表格中的文件关联的单元格不会从表格视图中删除。

当我滑动删除时，我有这个错误：

* 由于未捕获的异常“NSRangeException”而终止应用程序，原因：“* -[NSMutableArray objectAtIndex:]：索引 0 超出范围 对于空数组'

如何删除单元格？

MANAGER.h

NSMutableArray *contentArray;

MANAGER.m

- (id)initWithStyle:(UITableViewStyle)style {
if (self == [super initWithStyle:style]) {

     self.navigationController.navigationBar.tintColor = [UIColor blackColor];
    self.navigationItem.rightBarButtonItem = self.editButtonItem;
    contentArray = [[NSMutableArray alloc] init];
    progArray = [[NSMutableArray alloc] init];
    self.view.backgroundColor = [UIColor clearColor];

    //saveTo = [[NSUserDefaults standardUserDefaults] stringForKey:@"save_to"];

    AppDelegate_iPhone* delegate = (AppDelegate_iPhone *)[[UIApplication sharedApplication] delegate];
    if([delegate saveTo] != nil)
    {
        saveTo = [delegate saveTo];
    }

    if(saveTo == nil)
    {
        saveTo = @"/";
    }


    allFiles = [[NSMutableArray alloc] init];
    NSDirectoryEnumerator *dirEnum = [ [ NSFileManager defaultManager ] enumeratorAtPath:saveTo];
    NSString *file;
    while ((file = [ dirEnum nextObject ])) 
    {
        if(file != nil)
        {
            if([file rangeOfString:@".mp4" options: NSCaseInsensitiveSearch].length > 0 || [file rangeOfString:@".mov" options: NSCaseInsensitiveSearch].length > 0 || [file rangeOfString:@".m4v" options: NSCaseInsensitiveSearch].length > 0 || [file rangeOfString:@".pdf" options: NSCaseInsensitiveSearch].length > 0 )

            {
                [ allFiles addObject: file];
            }
        }
    }
}
return self;
}

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

    if(indexPath.section == 0)
    {

        if (editingStyle == UITableViewCellEditingStyleDelete) 
        {
            Selected = indexPath.row;
            //Remove The Temporary File
            NSFileManager *fileManager = [NSFileManager defaultManager];
            if([fileManager fileExistsAtPath:[(ASIHTTPRequest *)[contentArray objectAtIndex:indexPath.row] temporaryFileDownloadPath]])
            {
......


- (void)requestFailed:(ASIHTTPRequest *)request
    {

        [contentArray removeObject:request];
        [progArray removeObject:request];
        [self reloadMyData];
       [self.tableView reloadData];
    }

-(void)reloadMyData
{
    allFiles = [[NSMutableArray alloc] init];
    AppDelegate_iPhone* delegate = (AppDelegate_iPhone *)[[UIApplication sharedApplication] delegate];
    if([delegate saveTo] != nil)
    {
        saveTo = [delegate saveTo];
    }

    NSDirectoryEnumerator *dirEnum = [ [ NSFileManager defaultManager ] enumeratorAtPath:saveTo];
    NSString *file;
    while ((file = [ dirEnum nextObject ])) 
    {
        if(file != nil)
        {
            //if([file rangeOfString:@".mp4" options: NSCaseInsensitiveSearch].length > 0 || [file rangeOfString:@".mov" options: NSCaseInsensitiveSearch].length > 0 || [file rangeOfString:@".mp3" options: NSCaseInsensitiveSearch].length > 0 )
            if([file rangeOfString:@".mp4" options: NSCaseInsensitiveSearch].length > 0 || [file rangeOfString:@".mov" options: NSCaseInsensitiveSearch].length > 0 || [file rangeOfString:@".m4v" options: NSCaseInsensitiveSearch].length > 0 || [file rangeOfString:@".pdf" options: NSCaseInsensitiveSearch].length > 0)
            {
                [ allFiles addObject: file];
            }
        }
    }


}



#pragma mark -
#pragma mark Table view data source

- (NSInteger)numberOfSectionsInTableView:(UITableView *)aTableView {
    // Return the number of sections.
    return 2;
}


- (NSInteger)tableView:(UITableView *)aTableView numberOfRowsInSection:(NSInteger)section {
    // Return the number of rows in the section.
    if(section == 0)
    {
        return [progArray count];
    }
    else {
        return [allFiles count];
    }
}
- (UITableViewCell *)tableView:(UITableView *)tableView cellForRowAtIndexPath:(NSIndexPath *)indexPath {

    NSString *CellIdentifier = [NSString stringWithFormat:@"CellIdentifier_%i_%i",indexPath.section,indexPath.row];
    UITableViewCell *cell = [tableView dequeueReusableCellWithIdentifier:CellIdentifier];

    cell = nil;

    if(indexPath.section == 0)
    {
        if (cell == nil) {
            cell = [[[UITableViewCell alloc] initWithStyle:UITableViewCellStyleDefault reuseIdentifier:CellIdentifier] autorelease];
            cell.accessoryType = UITableViewCellAccessoryNone;
            cell.selectionStyle = UITableViewCellSelectionStyleNone;
        }
        [cell addSubview:[progArray objectAtIndex:indexPath.row]];
    }
    else {
        if (cell == nil) {
            cell = [[[UITableViewCell alloc] initWithStyle:UITableViewCellStyleDefault reuseIdentifier:CellIdentifier] autorelease];
        }
       // cell.accessoryType = UITableViewCellAccessoryNone;
        cell.selectionStyle = UITableViewCellSelectionStyleBlue;
        cell.textLabel.text = [allFiles objectAtIndex:indexPath.row];
    }


    return cell;
}

Answer 1

从 tableView 中删除一行时，您需要在删除该行的同时从数据源中删除该对象。如果从数据源中删除一行，则需要在删除时更新表（-deleteRowsAtIndexPaths:withRowAnimation:)，以维护tableView和数据源之间的关系。