Ios 选定行应用程序崩溃了吗

大家好，我正在学习一个教程，其中我解释了如何展开选定行的单元格

我已经实现了所有的数组并正确返回了数据，但是当我选择单元格来扩展我的应用程序时，崩溃了，返回了这个错误

[PFObject sizeWithFont:constrainedToSize:lineBreakMode:]：发送到实例的选择器无法识别

通过断点，我找到了点，但我不明白出了什么问题。。。 应用程序崩溃的点是

CGSize AltezzaLabel = [ [ ArrayforPost objectAtIndex : index ] sizew sizeWithFont : [ UIFont fontWithName : @ " Helvetica " size : 14.0f ] constrainedToSize : MAX lineBreakMode : NSLineBreakByCharWrapping ] ;

为了更好地理解，我在下面提供了实现

#import "FFTimeline.h"
#import "FFCustomCellTimelineSocial.h"

@interface FFTimeline ()
@end

@implementation FFTimeline
@synthesize ArrayforPost, NuovoArray;
@synthesize IsFlashPost;


- (void)viewDidLoad
{
    [super viewDidLoad];
    self.FFTableView.delegate = self;
    self.FFTableView.dataSource = self;
    CellaSelezionata = -1;

}

-(void)viewDidAppear:(BOOL)animated {
    [self QueryForPost];

}

- (NSInteger)numberOfSectionsInTableView:(UITableView *)tableView {
    return 1;
}

- (NSInteger)tableView:(UITableView *)tableView numberOfRowsInSection:(NSInteger)section {
       return [ArrayforPost count];

}

-(void)QueryForPost {

    PFQuery *QueryForFriend=[PFQuery queryWithClassName:FF_AMICIZIE_CLASS];
    [QueryForFriend whereKey:FF_AMICIZIE_A_USER equalTo:[PFUser currentUser]];
    [QueryForFriend whereKey:FF_AMICIZIE_STATO  equalTo:@"Confermato"];
    [QueryForFriend includeKey:FF_AMICIZIE_DA_USER];

    PFQuery *QueryYES = [PFQuery queryWithClassName:FF_POST_CLASS];
    [QueryYES whereKey:FF_POST_FLASH_POST_BOOLEANVALUE equalTo:[NSNumber numberWithBool:YES]];
    [QueryYES whereKey:FF_POST_SCELTI equalTo:[PFUser currentUser]];

    PFQuery *normalPostByFriends = [PFQuery queryWithClassName: FF_POST_CLASS];
    [normalPostByFriends whereKey: FF_POST_FLASH_POST_BOOLEANVALUE  equalTo: [NSNumber numberWithBool: NO]];
    [normalPostByFriends whereKey: FF_POST_UTENTE matchesKey:FF_AMICIZIE_DA_USER inQuery:QueryForFriend];

    PFQuery *normalPostByUser = [PFQuery queryWithClassName:FF_POST_CLASS];
    [normalPostByUser whereKey:FF_POST_FLASH_POST_BOOLEANVALUE  equalTo: [NSNumber numberWithBool: NO]];
    [normalPostByUser whereKey:FF_POST_UTENTE equalTo: [PFUser currentUser]];

    PFQuery *query = [PFQuery orQueryWithSubqueries:@[QueryYES,normalPostByFriends,normalPostByUser]];
    [query includeKey:FF_POST_UTENTE];
    [query orderByDescending:FF_CREATEDAT];
    [query findObjectsInBackgroundWithBlock:^(NSArray *results, NSError *error) {

        if (!error) {
            NSLog(@"%@", results);
            ArrayforPost = [[NSMutableArray alloc] init];
            for (PFObject *object in results) {
                [ArrayforPost addObject:object];
            }
            [self.FFTableView reloadData];
        }
    }];    

}


-(CGFloat)valoreAltezzaCella:(NSInteger)index {

    CGSize MAX = CGSizeMake(230, 10000);
    CGSize AltezzaLabel = [[ArrayforPost objectAtIndex:index] sizeWithFont:[UIFont fontWithName:@"Helvetica" size:14.0f] constrainedToSize:MAX lineBreakMode:NSLineBreakByWordWrapping];

    return AltezzaLabel.height;
}



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

    FFCustomCellTimelineSocial *cell = (FFCustomCellTimelineSocial * )[self.FFTableView dequeueReusableCellWithIdentifier:@"CellPost"];
    if (!cell) {
        cell = [[FFCustomCellTimelineSocial alloc] initWithStyle:UITableViewCellStyleDefault reuseIdentifier:@"CellPost"];
    }


    if (CellaSelezionata == indexPath.row) {
        CGFloat AltezzaLabel = [self valoreAltezzaCella: indexPath.row];
        cell.FFTestoUtenteLabel.frame = CGRectMake(cell.FFTestoUtenteLabel.frame.origin.x, cell.FFTestoUtenteLabel.frame.origin.y, cell.FFTestoUtenteLabel.frame.size.width, AltezzaLabel);
    } else {
        cell.FFTestoUtenteLabel.frame = CGRectMake(cell.FFTestoUtenteLabel.frame.origin.x, cell.FFTestoUtenteLabel.frame.origin.y, cell.FFTestoUtenteLabel.frame.size.width, 65);
    }

    PFObject *ObjectPost = [ArrayforPost objectAtIndex:indexPath.row];

    cell.FFTestoUtenteLabel.font = [UIFont fontWithName:@"Helvetica" size:14.0f];
    NSString *text = [ObjectPost objectForKey:@"Testo"];

    cell.FFTestoUtenteLabel.text = text;
    [cell.FFTestoUtenteLabel setLineBreakMode:NSLineBreakByWordWrapping];


    cell.backgroundCell.layer.masksToBounds = YES;
    cell.backgroundCell.layer.cornerRadius = 5.0f;


    cell.backgroundFotoProfilo.layer.masksToBounds = YES;
    cell.backgroundFotoProfilo.layer.cornerRadius = 35.0f;

    cell.FFImmagineUtente.layer.masksToBounds = YES;
    cell.FFImmagineUtente.layer.cornerRadius = 30.0f;
    cell.FFImmagineUtente.contentMode = UIViewContentModeScaleAspectFill;


    PFObject *rowObject = [ArrayforPost objectAtIndex:indexPath.row];

        if([[rowObject objectForKey:FF_POST_FLASH_POST_BOOLEANVALUE ] boolValue]) {
            cell.FlashPostImg.image = [UIImage imageNamed:@"FFNotificaFlash"];
        }

        else {
            cell.FlashPostImg.image =  [UIImage imageNamed:@" "];
        }



    return cell;
}

- (CGFloat)tableView:(UITableView *)tableView heightForRowAtIndexPath:(NSIndexPath *)indexPath;
{

    if (CellaSelezionata == indexPath.row)

    {
        return [self valoreAltezzaCella:indexPath.row] + 10 * 2;

    }

    else {
        return 65 + 10 * 2;
    }

}

-(NSIndexPath *)tableView:(UITableView *)tableView willSelectRowAtIndexPath:(NSIndexPath *)indexPath    {
    if ([self valoreAltezzaCella:indexPath.row] > 65) {
        return indexPath;
    } else {
        return nil;
    }
}

-(void)tableView:(UITableView *)tableView didSelectRowAtIndexPath:(NSIndexPath *)indexPath {
    if (CellaSelezionata == indexPath.row) {
        CellaSelezionata = -1;
        [tableView reloadRowsAtIndexPaths:[NSArray arrayWithObject:indexPath] withRowAnimation:UITableViewRowAnimationFade];
        return;
    }

    if (CellaSelezionata >=  0) {
        NSIndexPath *previousPath = [NSIndexPath indexPathForRow:CellaSelezionata inSection:0];
        CellaSelezionata = indexPath.row;
        [tableView reloadRowsAtIndexPaths:[NSArray arrayWithObject:previousPath] withRowAnimation:UITableViewRowAnimationFade];

    }

    CellaSelezionata = indexPath.row;
    [tableView reloadRowsAtIndexPaths:[NSArray arrayWithObject:indexPath] withRowAnimation:UITableViewRowAnimationFade];
}

---

在您的

valoreAltezzaCella:

方法中，

[ArrayforPost objectAtIndex:index]

是

PFObject

而不是

NSString

，因此您无法对其应用

sizeWithFont

。您可能想要类似于：

PFObject *objectPost = [ArrayforPost objectAtIndex:indexPath.row];
NSString *text = [objectPost objectForKey:@"Testo"];
CGSize altezzaLabel = [text sizeWithFont:[UIFont fontWithName:@"Helvetica" size:14.0f] constrainedToSize:MAX lineBreakMode:NSLineBreakByWordWrapping];

---

请复制你的真实代码。这段代码没有编译，因为它有很多语法错误。我通过插入整个文件来编辑代码。m P.S我使用的是Parse.com ArrayforPost中有什么类型的对象？l'数组包含了我为解析查询（PFQuery）而添加的所有项。它可以工作，现在应用程序不会崩溃并在单元格上创建动画，但标签的全文不会显示。。。发生了什么变化？