点击第一行时，在UITableView中插入新行 [英] Insert new row in UITableView when tapping first row

问题描述

我是iOS开发的新手.因此，如果您的回答尽可能详细，那将是很好的.我的问题如下:我希望第二部分的单元格始终说添加新行".如果单击此单元格，则应在顶部添加新行.我当前的代码是

I'm new to iOS development. Therefore it would be nice if your answer could be as detailed as possible. My problem is the following: I want the cell in my second section to always say "add new row". If you click this cell a new row should be added on top. My current code is

- (NSInteger)numberOfSectionsInTableView:(UITableView *)tableView
{

// Return the number of sections.
return 2;
 }
- (NSInteger)tableView:(UITableView *)tableView numberOfRowsInSection:(NSInteger)section
{

// Return the number of rows in the section.
if (section == 0) {
    return 1;
}
else {

    return [entries count];
}
}

- (UITableViewCell *)tableView:(UITableView *)tableView cellForRowAtIndexPath:(NSIndexPath        *)indexPath
{
static NSString *simpleTableIdentifier = @"Cell";
static NSString *todayTableIdentifier = @"Notification";
UITableViewCell *cell = [tableView       dequeueReusableCellWithIdentifier:simpleTableIdentifier];
UITableViewCell *todaycell = [tableView dequeueReusableCellWithIdentifier:todayTableIdentifier];

if (cell == nil) {
    cell = [[UITableViewCell alloc] initWithStyle:UITableViewCellStyleDefault reuseIdentifier:simpleTableIdentifier];


}
NSString *entry;
if (indexPath.section == 0) {
    entry = [notifications objectAtIndex:indexPath.row];
    cell = todaycell;
} else {
    entry = [entries objectAtIndex:indexPath.row];
}
cell.textLabel.text = entry;

return cell;

}

- (void)tableView:(UITableView *)tableView didSelectRowAtIndexPath:(NSIndexPath *)indexPath
{

int selectedRow = indexPath.row;
NSLog(@"row pressed %d", selectedRow);
NSArray *paths = [NSArray arrayWithObject:
                  [NSIndexPath indexPathForRow:2 inSection:2]];
if (selectedRow == 0)
{   [entries addObject:@"a new Entry"];
    [[self tableView] insertRowsAtIndexPaths:paths
                            withRowAnimation:UITableViewRowAnimationTop];
}
else {
    [[self tableView] deleteRowsAtIndexPaths:paths
                            withRowAnimation:UITableViewRowAnimationTop];
  }
}

不幸的是，我的应用程序不断崩溃.

Unfortunately, my app keeps crashing.

2013-04-11 16:52:39.717 MyStore[12924:c07] *** Assertion failure in -[UITableView    _endCellAnimationsWithContext:], /SourceCache/UIKit_Sim/UIKit-2380.17/UITableView.m:861
2013-04-11 16:52:39.718 MyStore[12924:c07] *** Terminating app due to uncaught exception '    NSInternalInconsistencyException', reason: 'attempt to delete row 2 from section 2, but there    are only 2 sections before the update'
*** First throw call stack:
(0x1faa012 0x13e7e7e 0x1fa9e78 0xb6d665 0xbb43c 0xca1f6 0xca271 0x5c6b 0xcb285 0xcb4ed    0xad55b3 0x1f69376 0x1f68e06 0x1f50a82 0x1f4ff44 0x1f4fe1b 0x1f047e3 0x1f04668 0x1bffc 0x21bd  0x20e5 0x1)
libc++abi.dylib: terminate called throwing an exception

推荐答案

那很正常，除了(在视觉上)添加新行之外，您还需要更新数据源(在这种情况下为通知数组).UI只是数据源的可视化.所以:

That's normal, besides adding a new row (visually), you need to update your Data Source (the notifications array in this case). The UI is just the visualization of your Data Source. So:

[notifications addObject:@"a new Entry"];

[[self tableView] insertRowsAtIndexPaths:paths
                            withRowAnimation:UITableViewRowAnimationTop];

当您删除时:

 [notifications removeObjectAtIndex:indexPath.row];

 [[self tableView] deleteRowsAtIndexPaths:paths
                            withRowAnimation:UITableViewRowAnimationTop];

这篇关于点击第一行时，在UITableView中插入新行的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持IT屋！