Question

我是iPhone编程新手。使用下面的代码我在缩略图中显示图像。在那里我们可以选择多个图像，我们也可以选择和取消选择图像。选择一些图像后，它会在下一个视图中显示所选图像。为此，我使用了另一种方法。但问题是它在缩略图中显示图像，但如果我选择任何图像意味着它显示一些异常。任何人都可以告诉我如何解决这个问题吗？

- (void)viewDidLoad
{   
    self.title=@"All Images";
        mImageSelected=[[NSMutableArray alloc]init];
    self.view.backgroundColor=[UIColor whiteColor];
    mFirst=[[UIImageView alloc]initWithImage:[UIImage imageNamed:@"one.jpg"]];
    mFirst.frame=CGRectMake(10, 10, 60, 50);

    UITapGestureRecognizer *singleTap = [[UITapGestureRecognizer alloc] 
                                         initWithTarget:self 
                                         action:@selector(actionHandleTapOnImageView:)];
    mFirst.userInteractionEnabled = YES;
    [mFirst addGestureRecognizer:singleTap];
    [self.view addSubview:mFirst];
    msSec=[[UIImageView alloc]initWithImage:[UIImage imageNamed:@"two.jpg"]];
    msSec.frame=CGRectMake(80, 10, 60, 50);
    UITapGestureRecognizer *secsingleTap = [[UITapGestureRecognizer alloc] 
                                         initWithTarget:self 
                                            action:@selector(actionHandleTapOnImageView:)];
    msSec.userInteractionEnabled = YES;
    [msSec addGestureRecognizer:secsingleTap];

    [self.view addSubview:msSec];
    mThird=[[UIImageView alloc]initWithImage:[UIImage imageNamed:@"three.jpg"]];
    mThird.frame=CGRectMake(150, 10, 60, 50);
    UITapGestureRecognizer *trdsingleTap = [[UITapGestureRecognizer alloc] 
                                            initWithTarget:self 
                                            action:@selector(actionHandleTapOnImageView:)];
    mThird.userInteractionEnabled = YES;
    [mThird addGestureRecognizer:trdsingleTap];

    [self.view addSubview:mThird];
    m4th=[[UIImageView alloc]initWithImage:[UIImage imageNamed:@"four.jpg"]];
    m4th.frame=CGRectMake(220, 10, 60, 50);
    UITapGestureRecognizer *frthsingleTap = [[UITapGestureRecognizer alloc] 
                                            initWithTarget:self 
                                             action:@selector(actionHandleTapOnImageView:)];

    m4th.userInteractionEnabled = YES;
    [m4th addGestureRecognizer:frthsingleTap];
    [self.view addSubview:m4th];
    m5th=[[UIImageView alloc]initWithImage:[UIImage imageNamed:@"five.jpg"]];
    m5th.frame=CGRectMake(10, 70, 60, 50);
    UITapGestureRecognizer *fifthsingleTap = [[UITapGestureRecognizer alloc] 
                                             initWithTarget:self 
                                              action:@selector(actionHandleTapOnImageView:)];

    m5th.userInteractionEnabled = YES;
    [m5th addGestureRecognizer:fifthsingleTap];
    [self.view addSubview:m5th];
    UIButton *theSshowButton=[[UIButton alloc]init];
    theSshowButton.frame=CGRectMake(100, 300, 100, 30);
    theSshowButton.layer.borderWidth=2;
    theSshowButton.layer.borderColor=[UIColor purpleColor].CGColor;
    theSshowButton.layer.cornerRadius=5;
    theSshowButton.backgroundColor=[UIColor greenColor];
    [theSshowButton setTitle:@"Show" forState:UIControlStateNormal];
    [theSshowButton setTitleColor:[UIColor whiteColor] forState:UIControlStateNormal];
    [theSshowButton addTarget:self action:@selector(show) forControlEvents:UIControlEventTouchUpInside];
    [self.view addSubview:theSshowButton];

    [super viewDidLoad];
    // Do any additional setup after loading the view, typically from a nib.
}
-(void)actionHandleTapOnImageView:(UITapGestureRecognizer *) in_ImageSenderTap
{ 
if (in_ImageSenderTap.view.tag ==0 )
  {


     mTick=[[UIImageView alloc]initWithImage:[UIImage imageNamed: @"mark.jpg"]];
     mTick.frame=CGRectMake(0, 0, in_ImageSenderTap.view.frame.size.width*0.3,  in_ImageSenderTap.view.frame.size.height*0.4);

      [mImageSelected addObject:[in_ImageSenderTap.view accessibilityIdentifier]];

        [in_ImageSenderTap.view addSubview:mTick];


      in_ImageSenderTap.view.tag=1;
    }
       else
    {
    for (UIView *subviews in in_ImageSenderTap.view.subviews)
        {


            UIImageView *theSubview=(UIImageView*)subviews;

            [theSubview removeFromSuperview];
            [mImageSelected removeObjectIdenticalTo:[in_ImageSenderTap.view accessibilityIdentifier]];

        }
        in_ImageSenderTap.view.tag=0;
    }


}

就像这样展示了一些Expect。

2013-03-01 12:01:21.332 ImageStuf[588:11303] *** Terminating app due to uncaught exception 'NSInvalidArgumentException', reason: '*** -[__NSArrayM insertObject:atIndex:]: object cannot be nil'
*** First throw call stack:
(0x159a012 0x12a7e7e 0x154db6a 0x154da20 0x37e0 0x4b685a 0x4b599b 0x4b70df 0x4b9d2d 0x4b9cac 0x4b1a28 0x21e972 0x21ee53 0x1fcd4a 0x1ee698 0x25fcdf9 0x25fcad0 0x150fbf5 0x150f962 0x1540bb6 0x153ff44 0x153fe1b 0x25fb7e3 0x25fb668 0x1ebffc 0x1cd2 0x1c05 0x1)
libc++abi.dylib: terminate called throwing an exception
(lldb)

如果我在此方法中注释下面的代码 -(void)actionHandleTapOnImageView:(UITapGestureRecognizer *) in_ImageSenderTap意味着它的工作正常，但不能将图像存储在数组中。任何人都可以告诉我如何解决这个问题谢谢阿斯拉姆

[mImageSelected addObject:[in_ImageSenderTap.view accessibilityIdentifier]];

Answer 1

对于多项选择，您可以使用PSTCollectionView。这样一个很棒的库也可以在iOS 5中作为gridView工作，在iOS6上面它可以作为UICollectionView使用。

一切顺利!!!

Answer 2

首先，为什么要在数组中插入accessibilityIdentifier，当你可以改为添加缩略图时呢？这将确保您不添加nil，这是产生崩溃的原因。您没有在缩略图上设置accessibilityIdentifier。

其次，为什么要创建UITapGestureRecognizer的5个实例？只需在addGestureRecognizer:时使用相同的实例，就不需要5个版本。

Answer 3

您尝试将nil插入NSArray，因此它引发了异常。你应该检查要插入的元素。

我认为您可以使用ALAssetLibrary来选择多张图片：

[_assetsLibrary enumerateGroupsWithTypes:ALAssetsGroupAll usingBlock:^(ALAssetsGroup *group, BOOL *stop) {
    if (group) {
        [self.groupArray addObject:group];
    }
} failureBlock:^(NSError *error) {
    NSLog(@"Group not found!\n");
}];

- (void)getImages
{
    if (!self.assetsArray) {
        _assetsArray = [[NSMutableArray alloc] init];
    }

    if (!self.assetsLibrary) {
        _assetsLibrary = [[ALAssetsLibrary alloc] init];
    }

    @autoreleasepool {
        [self.assetsGroup enumerateAssetsUsingBlock:^(ALAsset *result, NSUInteger index, BOOL *stop) {
            if (result) {
                TTAsset *ttAsset = [[TTAsset alloc] initWithAsset:result];
                [self.assetsArray addObject:ttAsset];
                [ttAsset release], ttAsset = nil;
            }
        }];
    }

    [self.tableView reloadData];
}

之后，您可以使用ALAsset的缩略图属性。

ELCImagePickerController是一个很好的起点。

在iphone中没有选择多个图像

3 个答案: