Question

我有一个表视图，它使用两个不同的表格单元标识符（两个不同的自定义单元格）。如果field_swaptime为null，我希望我的表视图使用一个单元格;如果field_swaptime包含数据，我希望它使用另一个。也就是说，出于某种原因，我的表视图仅使用ChatTableCell（而不是SwapDetailTableCell，无论field_swaptime包含什么）。有谁知道为什么会这样？

以下是数据＆＃39;吐出（self.messages） - 即使field_swaptime在某些情况下有数据而在另一种情况下为null，同一个自定义单元格用于所有结果：

> THIS IS DATA {
>     body = "28-10-2016 18:05\n";
>     endswaptime = "28-10-2016 19:05";
>     name = Brittany;
>     "node_title" = "Title";
>     "published at" = "Saturday, October 29, 2016 - 00:05";
>     swaptime = "28-10-2016 18:05";
>     targetuser = 93;
>     uid = 47; } 2016-10-28 21:37:16.196852 [2594:626224] Message Received at Saturday, October 29, 2016 - 00:05 2016-10-28
> 21:37:16.197365 [2594:626224] THIS IS DATA {
>     body = "04-11-2016 12:54\n";
>     endswaptime = "13-12-2016 21:54";
>     name = Brittany;
>     "node_title" = "Title!";
>     "published at" = "Friday, October 28, 2016 - 23:55";
>     swaptime = "04-11-2016 12:54";
>     targetuser = 93;
>     uid = 47; } 2016-10-28 21:37:16.197688n [2594:626224] Message Received at Friday, October 28, 2016 - 23:55 2016-10-28
> 21:37:16.198268 [2594:626224] THIS IS DATA {
>     body = "why";
>     endswaptime = "<null>";
>     name = Brittany;
>     "node_title" = "Re:";
>     "published at" = "Friday, October 28, 2016 - 23:50";
>     swaptime = "<null>";
>     targetuser = 93;
>     uid = 47; }

这是我的代码：

的.m

- (void)viewDidLoad {
    [super viewDidLoad];


   static NSString *ChatTableIdentifier = @"ChatTableViewCell";
   static NSString *ChatTableIdentifier2 = @"SwapDetailTableViewCell";


    UINib *nib = [UINib nibWithNibName: ChatTableIdentifier bundle:nil];
    [self.tableView registerNib:nib forCellReuseIdentifier: ChatTableIdentifier];

    UINib *nib2 = [UINib nibWithNibName: ChatTableIdentifier2 bundle:nil];
    [self.tableView registerNib:nib2 forCellReuseIdentifier: ChatTableIdentifier2];

}

- (UITableViewCell *)tableView:(UITableView *)tableView cellForRowAtIndexPath:(NSIndexPath *)indexPath
{

   static NSString *ChatTableIdentifier = @"ChatTableViewCell";
   static NSString *ChatTableIdentifier2 = @"SwapDetailTableViewCell";


    NSDictionary *data = [self.messages objectAtIndex:indexPath.row];


   if (![data objectForKey:@"field_swaptime"]) {

     NSLog(@"THIS IS DATA %@", data);

       ChatTableViewCell *cell = (ChatTableViewCell *)[tableView dequeueReusableCellWithIdentifier:ChatTableIdentifier forIndexPath:indexPath];


       NSString *userName = [data objectForKey:@"name"];
       [cell.sendingUser setText:userName];

       NSString *messageBody = [data objectForKey:@"body"];
       [cell.messageDisplayed setText:messageBody];

       NSString *timeReceived = [data objectForKey:@"published at"];
       NSLog(@"Message Received at %@", timeReceived);
       [cell.timeStamp setText:timeReceived];


     return cell;

              }

    else {


        SwapDetailTableViewCell *cell = (SwapDetailTableViewCell *)[tableView dequeueReusableCellWithIdentifier:ChatTableIdentifier2 forIndexPath:indexPath];



        NSString *Time = [data objectForKey:@"field_swaptime"];
        NSLog(@"This is time %@", Time);
        [cell.startTime setText:Time];

        NSString *TimeEnd = [data objectForKey:@"field_endswaptime"];
        [cell.endTime setText:TimeEnd];

        return cell;

    }

    }

Answer 1

尝试访问data中的值时，您遇到了几个问题。

首先，没有field_swaptime这样的密钥。有一个键swaptime。但是一旦你修复了这个引用，你需要知道一些值有一个实际的日期值，有些值有一个“null”值（来自NSNull），所以你对该键存在的简单检查是不够的。

试试这个：

- (UITableViewCell *)tableView:(UITableView *)tableView cellForRowAtIndexPath:(NSIndexPath *)indexPath
{
    NSDictionary *data = self.messages[indexPath.row];
    NSLog(@"THIS IS DATA %@", data);
    id swaptime = data[@"swaptime"];
    if ([swaptime isKindOfClass:[NSString class]]) {
        // There is a valid "swaptime" value
        static NSString *ChatTableIdentifier2 = @"SwapDetailTableViewCell";

        SwapDetailTableViewCell *cell = (SwapDetailTableViewCell *)[tableView dequeueReusableCellWithIdentifier:ChatTableIdentifier2 forIndexPath:indexPath];

        NSString *time = data[@"swaptime"];
        cell.startTime.text = time;

        NSString *timeEnd = data[@"endswaptime"];
        cell.endTime.text = timeEnd;

        return cell;
    } else {
        static NSString *ChatTableIdentifier = @"ChatTableViewCell";

        ChatTableViewCell *cell = (ChatTableViewCell *)[tableView dequeueReusableCellWithIdentifier:ChatTableIdentifier forIndexPath:indexPath];

        NSString *userName = data[@"name"];
        cell.sendingUser.text = userName;

        NSString *messageBody = data[@"body"];
        cell.messageDisplayed.text = messageBody;

        NSString *timeReceived = data[@"published at"];
        cell.timeStamp.text = timeReceived;

        return cell;
    }
}

上面的代码还清理了许多其他小东西，例如使用现代语法来访问数组和字典值。它还会移动static变量，因此它们只在需要的范围内。

TableView不使用两个不同的自定义表视图单元标识符

1 个答案: