Question

我有一个视图需要等到从Web服务检索数据然后更新UI选择器视图。当我等待响应时，如果用户滚动选择器视图，应用程序崩溃，我得到lldb错误。有什么理由吗？

这是我的代码：

@interface LocavoreRetroSecondViewController ()

@end

@implementation LocavoreRetroSecondViewController

- (id)initWithNibName:(NSString *)nibNameOrNil bundle:(NSBundle *)nibBundleOrNil
{
    self = [super initWithNibName:nibNameOrNil bundle:nibBundleOrNil];
    if (self) {
        self.title = NSLocalizedString(@"I Ate Local", @"I Ate Local");
        self.tabBarItem.image = [UIImage imageNamed:@"newfood"];
        _dataController = [[InSeasonProductDataController alloc] init];
    }
    return self;
}

- (void)viewDidLoad
{
    [super viewDidLoad];

}

- (NSInteger)numberOfComponentsInPickerView:(UIPickerView *)pickerView {
    return 1;
}

- (NSInteger)pickerView:(UIPickerView *)pickerView numberOfRowsInComponent:(NSInteger)component {
    return [_dataController countOfList];
}
- (NSString *)pickerView:(UIPickerView *)pickerView titleForRow:(NSInteger)row forComponent:(NSInteger)component {
    Product *product = [_dataController objectInListAtIndex:row];
    return product.name;
}

- (void)pickerView:(UIPickerView *)thePickerView didSelectRow:(NSInteger)row inComponent:(NSInteger)component {

    //do something
}



- (void)didReceiveMemoryWarning
{
    [super didReceiveMemoryWarning];
    // Dispose of any resources that can be recreated.
}

- (void)dealloc{
    [_dataController release];
    [super dealloc];
}

我收到此错误：

* 断言失败 - [UITableViewRowData rectForRow：inSection：]，/ SourceCache / UIKit_Sim / UIKit-2380.17 / UITableViewRowData.m：1630 （lldb）

Answer 1

将代码更改为：

- (NSInteger)pickerView:(UIPickerView *)pickerView numberOfRowsInComponent:(NSInteger)component {

if ([_dataController countOfList]>0) {
    return [_dataController countOfList];
}else{
     return 1;
}

}

- (NSString *)pickerView:(UIPickerView *)pickerView titleForRow:(NSInteger)row forComponent:(NSInteger)component {
if ([_dataController countOfList]>0) {
Product *product = [_dataController objectInListAtIndex:row];
return product.name;
}else{
    return @"";
}
}

ios：当我尝试滚动时UIPickerView lldb错误

1 个答案: