*编辑：对不起，刚刚意识到 - 这段代码工作正常，直到我让表格有三个部分。当它是带有章节标题的单个部分时，evrything在滚动时工作正常。现在我有滚动时崩溃的部分。*
我正在向一个uitablecell添加一个按钮。当表格内容超出表格高度时，会发生崩溃，并且表格会滚动到最底部。
从错误看起来好像UIButton没有被创建，它报告回来了JobsCell ......
自定义UITableCell中的布局也出错了。对于需要重复使用并显示在屏幕上的单元格，看起来好像没有启动JobsCell类吗？
2014-03-20 15:20:32.080 myApp[52350:60b] mapBtn: <UIButton: 0xa89aff0; frame = (0 0; 59 59); opaque = NO; autoresize = RM+BM; tag = 12; layer = <CALayer: 0xa89b1a0>> 2 1
2014-03-20 15:20:32.313 myApp[52350:60b] mapBtn: <UIButton: 0xa460620; frame = (0 0; 59 59); opaque = NO; autoresize = RM+BM; tag = 12; layer = <CALayer: 0xa469b60>> 0 11
2014-03-20 15:20:33.512 myApp[52350:60b] mapBtn: <JobsCell: 0xa761ac0; baseClass = UITableViewCell; frame = (0 775; 320 60); autoresize = W; tag = 12; layer = <CALayer: 0xa761e20>> 0 12
2014-03-20 15:20:33.512 myApp[52350:60b] -[JobsCell addTarget:action:forControlEvents:]: unrecognized selector sent to instance 0xa761ac0
2014-03-20 15:20:33.514 myApp[52350:60b] *** Terminating app due to uncaught exception 'NSInvalidArgumentException', reason: '-[JobsCell addTarget:action:forControlEvents:]: unrecognized selector sent to instance 0xa761ac0'
*** First throw call stack:
(
0 CoreFoundation 0x024461e4 __exceptionPreprocess + 180
1 libobjc.A.dylib 0x020178e5 objc_exception_throw + 44
2 CoreFoundation 0x024e3243 -[NSObject(NSObject) doesNotRecognizeSelector:] + 275
3 CoreFoundation 0x0243650b ___forwarding___ + 1019
4 CoreFoundation 0x024360ee _CF_forwarding_prep_0 + 14
5 ESC GasCert 0x0014a109 -[Home_IPVC tableView:cellForRowAtIndexPath:] + 2873
6 UIKit 0x00a5d11f -[UITableView _createPreparedCellForGlobalRow:withIndexPath:] + 412
7 UIKit 0x00a5d1f3 -[UITableView _createPreparedCellForGlobalRow:] + 69
8 UIKit 0x00a3ede7 -[UITableView _updateVisibleCellsNow:] + 2197
9 UIKit 0x00a536a5 -[UITableView layoutSubviews] + 213
10 UIKit 0x009d3964 -[UIView(CALayerDelegate) layoutSublayersOfLayer:] + 355
11 libobjc.A.dylib 0x0202982b -[NSObject performSelector:withObject:] + 70
12 QuartzCore 0x0429445a -[CALayer layoutSublayers] + 148
13 QuartzCore 0x04288244 _ZN2CA5Layer16layout_if_neededEPNS_11TransactionE + 380
14 QuartzCore 0x042880b0 _ZN2CA5Layer28layout_and_display_if_neededEPNS_11TransactionE + 26
15 QuartzCore 0x041ee7fa _ZN2CA7Context18commit_transactionEPNS_11TransactionE + 294
16 QuartzCore 0x041efb85 _ZN2CA11Transaction6commitEv + 393
17 QuartzCore 0x042bccc6 _ZN2CA7Display11DisplayLink14dispatch_itemsEyyy + 474
18 QuartzCore 0x042bd147 _ZN2CA7Display16TimerDisplayLink8callbackEP16__CFRunLoopTimerPv + 123
19 CoreFoundation 0x02404ac6 __CFRUNLOOP_IS_CALLING_OUT_TO_A_TIMER_CALLBACK_FUNCTION__ + 22
20 CoreFoundation 0x024044ad __CFRunLoopDoTimer + 1181
21 CoreFoundation 0x023ec538 __CFRunLoopRun + 1816
22 CoreFoundation 0x023eb9d3 CFRunLoopRunSpecific + 467
23 CoreFoundation 0x023eb7eb CFRunLoopRunInMode + 123
24 GraphicsServices 0x036585ee GSEventRunModal + 192
25 GraphicsServices 0x0365842b GSEventRun + 104
26 UIKit 0x00964f9b UIApplicationMain + 1225
27 ESC GasCert 0x0001626d main + 141
28 ESC GasCert 0x00002865 start + 53
)
libc++abi.dylib: terminating with uncaught exception of type NSException
但两个类中的代码相同（除了行转动单元格外）。
- (UITableViewCell *)tableView:(UITableView *)tableView cellForRowAtIndexPath:(NSIndexPath *)indexPath
{
static NSString *CellIdentifier = @"JobCell";
UITableViewCell *cell;
NSArray *versionCompatibility = [[UIDevice currentDevice].systemVersion componentsSeparatedByString:@"."];
if ( 6 <= [[versionCompatibility objectAtIndex:0] intValue] )
{
// iOS6 is installed
cell = [tableView dequeueReusableCellWithIdentifier:CellIdentifier forIndexPath:indexPath];
}
else
{
// iOS5 is installed
cell = [tableView dequeueReusableCellWithIdentifier:CellIdentifier ];
}
// * ios7 table fix
[cell setBackgroundColor:[UIColor clearColor]];
Job *job = 0;
int jobsaved = 0;
NSString *jobString = @"";
NSString *jobPostcode = @"";
NSString *jobDate = @"";
// Configure the cell...
if (indexPath.section==0)
{
job = [self.jobs objectAtIndex:indexPath.row];
jobsaved = job.jobSaved;
jobString = job.jobAddress;
jobPostcode = job.jobPostcode;
jobDate = job.jobDate;
}
else if (indexPath.section==1)
{
job = [self.jobsCommercial objectAtIndex:indexPath.row];
jobsaved = job.jobSaved;
jobString = job.jobAddress;
jobPostcode = job.jobPostcode;
jobDate = job.jobDate;
}
else if (indexPath.section==2)
{
Service *service = [self.jobsServices objectAtIndex:indexPath.row];
jobsaved = service.jobSaved;
jobString = service.jobAddress;
jobPostcode = service.jobPostcode;
jobDate = service.jobDate;
}
UIColor *redcol = [UIColor colorWithRed:0.62745098039216 green:0.15294117647059 blue:0.15686274509804 alpha:1.0];
jobString = [jobString stringByAppendingString:@", "];
jobString = [jobString stringByAppendingString:jobPostcode];
//cell.textLabel.text = jobString;
UILabel *jobLabel = (UILabel *)[cell viewWithTag:10];
jobLabel.text = jobString;
if (jobsaved == 1)
{
jobLabel.textColor = redcol;
}
else
{
jobLabel.textColor = [UIColor blackColor];
}
UILabel *dateLabel = (UILabel *)[cell viewWithTag:11];
if (! [jobDate isEqualToString:@""]) {
NSDateFormatter *formater = [[NSDateFormatter alloc] init];
[formater setDateFormat:@"yyyy-MM-dd"];
NSDate *date2 = [formater dateFromString:jobDate];
[formater setDateFormat:@"d MMM YYYY"];
NSString *date = [formater stringFromDate:date2];
dateLabel.text = date;
}
else
{
dateLabel.text = @"";
}
UIButton *mapBtn = (UIButton *)[cell viewWithTag:12];
NSLog(@"mapBtn: %@ %d %d",mapBtn, indexPath.section, indexPath.row);
[mapBtn addTarget:self action:@selector(showMap:) forControlEvents:UIControlEventTouchUpInside];
cell.tag = indexPath.row;
return cell;
}
JobsCell.h
#import <UIKit/UIKit.h>
@interface JobsCell : UITableViewCell
@property (nonatomic, strong) IBOutlet UILabel *jobLabel;
@property (nonatomic, strong) IBOutlet UILabel *dateLabel;
@property (nonatomic, strong) IBOutlet UIButton *mapBtn;
@end
JobsCell.m
#import "JobsCell.h"
@implementation JobsCell
@synthesize jobLabel;
- (id)initWithStyle:(UITableViewCellStyle)style reuseIdentifier:(NSString *)reuseIdentifier
{
self = [super initWithStyle:style reuseIdentifier:reuseIdentifier];
if (self) {
// Initialization code
}
return self;
}
- (void)setSelected:(BOOL)selected animated:(BOOL)animated
{
[super setSelected:selected animated:animated];
// Configure the view for the selected state
}
@end
答案 0 :(得分：3)
从您的日志中我们可以看到 tag = 12; JobsCell对象不是UIButton
mapBtn: <JobsCell: 0xa761ac0; baseClass = UITableViewCell; frame = (0 775; 320 60); autoresize = W; **tag = 12;** layer = <CALayer: 0xa761e20>> 0 12
此行cell.tag = indexPath.row;中的问题来源因为也可能是12
答案 1 :(得分：0)
您的单元格已将标记设置为indexPath.row cell.tag = indexPath.row;
让我们试试下面的
[cell.mapBtn addTarget:self action:@selector(showMap:) forControlEvents:UIControlEventTouchUpInside];
谢谢！
答案 2 :(得分：0)
您尝试通过某些未定义标记（ 12 ）获取按钮。您可以通过替换以下代码来简化您的生活：
- (UITableViewCell *)tableView:(UITableView *)tableView cellForRowAtIndexPath:(NSIndexPath *)indexPath
{
static NSString *CellIdentifier = @"JobCell";
JobsCell *cell;
if ([tableView respondsToSelector:@selector(dequeueReusableCellWithIdentifier:forIndexPath:)])
{
// iOS6 is installed
cell = (JobsCell *)[tableView dequeueReusableCellWithIdentifier:CellIdentifier forIndexPath:indexPath];
}
else
{
// iOS5 is installed
cell = (JobsCell *)[tableView dequeueReusableCellWithIdentifier:CellIdentifier ];
}
// * ios7 table fix
[cell setBackgroundColor:[UIColor clearColor]];
Job *job = nil;
int jobsaved = 0;
NSString *jobString = @"";
NSString *jobPostcode = @"";
NSString *jobDate = @"";
// Configure the cell...
if (indexPath.section==0)
{
job = [self.jobs objectAtIndex:indexPath.row];
jobsaved = job.jobSaved;
jobString = job.jobAddress;
jobPostcode = job.jobPostcode;
jobDate = job.jobDate;
}
else if (indexPath.section==1)
{
job = [self.jobsCommercial objectAtIndex:indexPath.row];
jobsaved = job.jobSaved;
jobString = job.jobAddress;
jobPostcode = job.jobPostcode;
jobDate = job.jobDate;
}
else if (indexPath.section==2)
{
Service *service = [self.jobsServices objectAtIndex:indexPath.row];
jobsaved = service.jobSaved;
jobString = service.jobAddress;
jobPostcode = service.jobPostcode;
jobDate = service.jobDate;
}
UIColor *redcol = [UIColor colorWithRed:0.62745098039216 green:0.15294117647059 blue:0.15686274509804 alpha:1.0];
jobString = [jobString stringByAppendingString:@", "];
jobString = [jobString stringByAppendingString:jobPostcode];
//cell.textLabel.text = jobString;
UILabel *jobLabel = (UILabel *)[cell viewWithTag:10];
jobLabel.text = jobString;
if (jobsaved == 1)
{
jobLabel.textColor = redcol;
}
else
{
jobLabel.textColor = [UIColor blackColor];
}
UILabel *dateLabel = (UILabel *)[cell viewWithTag:11];
if (! [jobDate isEqualToString:@""]) {
NSDateFormatter *formater = [[NSDateFormatter alloc] init];
[formater setDateFormat:@"yyyy-MM-dd"];
NSDate *date2 = [formater dateFromString:jobDate];
[formater setDateFormat:@"d MMM YYYY"];
NSString *date = [formater stringFromDate:date2];
dateLabel.text = date;
}
else
{
dateLabel.text = @"";
}
UIButton *mapBtn = cell.mapBtn;
NSLog(@"mapBtn: %@ %d %d",mapBtn, indexPath.section, indexPath.row);
[mapBtn addTarget:self action:@selector(showMap:) forControlEvents:UIControlEventTouchUpInside];
cell.tag = indexPath.row;
return cell;
}
还请注意我如何测试我调用的dequeueReusableCell方法 - 您永远不应该检查系统版本号。
指针应设置为nil，而不是0。