xcode 使用 indexPath.row 从数组中获取对象
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Using indexPath.row to get an object from an array
提问by ebsp
How do i use indexPath.row to get an object from an array? I have tried with the following code but it returns "signal SIGABRT".. Please help
如何使用 indexPath.row 从数组中获取对象？我已尝试使用以下代码，但它返回“信号 SIGABRT”.. 请帮忙
- (UITableViewCell *)tableView:(UITableView *)tableView cellForRowAtIndexPath:(NSIndexPath *)indexPath
{
static NSString *CellIdentifier = @"Cell";
UITableViewCell *cell = [tableView dequeueReusableCellWithIdentifier:CellIdentifier];
if (cell == nil) {
cell = [[[UITableViewCell alloc] initWithStyle:UITableViewCellStyleDefault reuseIdentifier:CellIdentifier] autorelease];
}
NSString *inde = [NSString stringWithFormat:@"%d", indexPath.row];
NSNumber *num = [NSNumber numberWithInteger: [inde integerValue]];
int intrNum = [num intValue];
NSString *name = [basket objectAtIndex:intrNum];
cell.textLabel.text = name;
return cell;
}
- (void)viewDidLoad
{
[super viewDidLoad];
basket = [[NSMutableArray alloc] init];
[basket addObject:@"1"];
[self makeGrid];
}
- (void)addToBasket:(id)sender {
NSInteger prodID = ((UIControl*)sender).tag;
[basket insertObject:[NSNumber numberWithInt:prodID] atIndex:0];
[self.tableView reloadData];
}
Error message:
错误信息：
-[__NSCFNumber isEqualToString:]: unrecognized selector sent to instance 0x6866080 2012-05-05 02:29:18.208 app[7634:f803] *** Terminating app due to uncaught exception 'NSInvalidArgumentException', reason: '-[__NSCFNumber isEqualToString:]: unrecognized selector sent to instance 0x6866080'
回答by Titouan de Bailleul
Why don't you just use
你为什么不直接使用
NSString *name = [basket objectAtIndex:indexPath.row];
?
?
回答by onegray
In addToBasketmethod you put NSNumberobject into basketarray, but in cellForRowAtIndexPathmethod you expect NSStringobjects in basket. To make your code working you can use safe conversion to string:
在addToBasket方法你把NSNumber对象变成basket阵列，但在cellForRowAtIndexPath方法你期望NSString中的对象basket。为了使您的代码正常工作，您可以使用安全转换为字符串：
NSString *name = [NSString stringWithFormat:@"%@",[basket objectAtIndex:intrNum]];
回答by Sakares
When your code
当你的代码
int intrNum = [num intValue];
the intrNummay is not real IndexPath Integer it may return the kind of address (example like '88792' or etc.) . So, It will cause problem with your array
在intrNum5月是不是真正的IndexPath整数，可以返还类型的地址（例如像“88792”或等）。所以，它会导致你的阵列出现问题
Correct your get object from array code in cellForRowAtIndexPathlike this
cellForRowAtIndexPath像这样从数组代码中更正您的 get 对象
- (UITableViewCell *)tableView:(UITableView *)tableView cellForRowAtIndexPath:(NSIndexPath *)indexPath
{
static NSString *CellIdentifier = @"Cell";
UITableViewCell *cell = [tableView dequeueReusableCellWithIdentifier:CellIdentifier];
if (cell == nil) {
cell = [[[UITableViewCell alloc] initWithStyle:UITableViewCellStyleDefault reuseIdentifier:CellIdentifier] autorelease];
}
/* NSString *inde = [NSString stringWithFormat:@"%d", indexPath.row];
NSNumber *num = [NSNumber numberWithInteger: [inde integerValue]];
int intrNum = [num intValue]; */
NSString *name = [basket objectAtIndex:indexPath.row];
cell.textLabel.text = name;
return cell;
}
}
and in the addToBasketyou should not use numberWithIntlike the reason about intthat I've mentioned above.
并且在addToBasket您不应该使用我上面提到numberWithInt的原因int。
- (void)addToBasket:(id)sender {
NSInteger prodID = ((UIControl*)sender).tag;
// [basket insertObject:[NSNumber numberWithInt:prodID] atIndex:0];
[basket insertObject:[NSNumber numberWithInteger:prodID] atIndex:0];
[self.tableView reloadData];
}
Hope it helps you!
希望对你有帮助！
