如何使用objective-c从数组中选择不同的图像

Posted 2023-03-11

【中文标题】如何使用objective-c从数组中选择不同的图像

【英文标题】：how to select the images differently from array using objective-c

【发布时间】：2017-10-04 07:10:52

【问题描述】：

我在 NSArray 中存储了 10 张图像。 在 UIViewController 我放置了 6 个 UIImageView，并在 .h 文件中给出了出口。

我需要从数组中选择任意6张图片怎么办？ 并且需要在 UIImageView 中显示图片。

- (void)viewDidLoad 
    [super viewDidLoad];
         images=[[NSMutableArray alloc]initWithObjects:[UIImage imageNamed:@"Navarre-Family-Eye-Care-Navarre-Florida-Optometrist-Santa-Christmas-Toy-Safety.jpg"],[UIImage imageNamed:@"Christmas-Wallpapers-HD-Picture.jpg"],[UIImage imageNamed:@"Christmas-Wallpaper-jesus-9413550-1024-768.jpg"],[UIImage imageNamed:@"tree.jpg"],[UIImage imageNamed:@"luxury-christmas-napkins-father-christmas-1635-p.jpg"],[UIImage imageNamed:@"Navarre-Family-Eye-Care-Navarre-Florida-Optometrist-Santa-Christmas-Toy-Safety.jpg"],[UIImage imageNamed:@"Christmas-Wallpapers-HD-Picture.jpg"],[UIImage imageNamed:@"Christmas-Wallpaper-jesus-9413550-1024-768.jpg"],[UIImage imageNamed:@"tree.jpg"],[UIImage imageNamed:@"luxury-christmas-napkins-father-christmas-1635-p.jpg"], nil];

            NSString *dd=[NSString stringWithFormat:@"%@", images];
            NSLog(@"%@",dd);
            
    - (void)setImagesForImageViews:(NSArray<UIImageView*>*)viewsArray fromArray:(NSArray<UIImage*>*)imageArray 
        if(images == nil || viewsArray == nil || viewsArray.count > images.count) 
            return; // early return
        

        NSMutableArray* randomImageArray = [NSMutableArray arrayWithCapacity:viewsArray.count];
        while (randomImageArray.count < viewsArray.count) 
            UIImage* image;
            do 
                NSUInteger random = (NSUInteger)arc4random_uniform(images.count);
                image = [imageArray objectAtIndex:random];
             while ([randomImageArray containsObject:image]);
            [randomImageArray addObject:image];
        
        [viewsArray enumerateObjectsUsingBlock:^(UIImageView * _Nonnull obj, NSUInteger idx, BOOL * _Nonnull stop) 
            obj.image = [randomImageArray objectAtIndex:idx];
        ];
    

在.h文件中

#导入

@interface memory_test : UIViewController

    NSMutableArray *images;

@property(weak,nonatomic)IBOutlet UIImageView *b1;
@property(weak,nonatomic)IBOutlet UIImageView *b2;
@property(weak,nonatomic)IBOutlet UIImageView  *b3;
@property(weak,nonatomic)IBOutlet UIImageView *b4;
@property(weak,nonatomic)IBOutlet UIImageView  *b5;
@property(weak,nonatomic)IBOutlet UIImageView  *b6;

【问题讨论】：

随机设置任意三张图片？

问题不清楚。要显示 3 张随机图片吗？

不清楚您的要求。请提及您做了什么以及您面临的问题。 SO 不是用来问关于howtos的问题

【参考方案1】：

让我们假设（因为问题不清楚），您想将随机图像设置为图像数组中的图像视图。这里的挑战是从数组中找到随机图像，不重复。

我还没有测试过代码，但是这样的东西应该可以工作：

- (void)viewDidLoad 
    [super viewDidLoad];
    NSArray* images = [self imagesArray];
    NSArray* views = [self imageViewsArray];
    [self setRandomImagesForImageViews:views fromArray:images];


- (NSArray<UIImage*>*)imagesArray 
    return @[[UIImage imageNamed:@"Navarre-Family-Eye-Care-Navarre-Florida-Optometrist-Santa-Christmas-Toy-Safety.jpg"],[UIImage imageNamed:@"Christmas-Wallpapers-HD-Picture.jpg"],[UIImage imageNamed:@"Christmas-Wallpaper-jesus-9413550-1024-768.jpg"],[UIImage imageNamed:@"tree.jpg"],[UIImage imageNamed:@"luxury-christmas-napkins-father-christmas-1635-p.jpg"],[UIImage imageNamed:@"Navarre-Family-Eye-Care-Navarre-Florida-Optometrist-Santa-Christmas-Toy-Safety.jpg"],[UIImage imageNamed:@"Christmas-Wallpapers-HD-Picture.jpg"],[UIImage imageNamed:@"Christmas-Wallpaper-jesus-9413550-1024-768.jpg"],[UIImage imageNamed:@"tree.jpg"],[UIImage imageNamed:@"luxury-christmas-napkins-father-christmas-1635-p.jpg"]];


- (NSArray<UIImageView*>*)imageViewsArray 
    return @[_b1, _b2, _b3, _b4, _b5, _b6];


- (void)setRandomImagesForImageViews:(NSArray<UIImageView*>*)viewsArray fromArray:(NSArray<UIImage*>*)imageArray 
    if(imageArray == nil || viewsArray == nil || viewsArray.count > imageArray.count) 
        return; // early return
    

    NSMutableArray* randomImageArray = [NSMutableArray arrayWithCapacity:viewsArray.count];
    while (randomImageArray.count < viewsArray.count) 
        UIImage* image;
        do 
            NSUInteger random = (NSUInteger)arc4random_uniform(imageArray.count);
            image = [imageArray objectAtIndex:random];
         while ([randomImageArray containsObject:image]);
        [randomImageArray addObject:image];
    
    [viewsArray enumerateObjectsUsingBlock:^(UIImageView * _Nonnull obj, NSUInteger idx, BOOL * _Nonnull stop) 
        obj.image = [randomImageArray objectAtIndex:idx];
    ];

如果您不再在课堂上使用它，您可以从头文件中删除您的图像数组声明。

【讨论】：

我有 6 个 UIImageview 那么如何设置

您可以通过将 imageview 出口保存在数组中来使其更通用。

@teena：改了代码，你只需要把images数组和imageview数组传给这个函数。

视图中如何调用这个函数

@teena：我猜你已经有了一个图像视图数组。您需要创建一个图像视图数组，然后使用图像视图数组和图像数组调用此函数。

【参考方案2】：

适用于 SWIFT

 class ViewController: UIViewController 
    //array with ImageView
    @IBOutlet var imageViews: [UIImageView]!
    //array with Image
    lazy var imagesArray = [UIImage]()


    override func viewDidLoad() 
        super.viewDidLoad()

        //initiate image
        let imageOne :UIImage = #imageLiteral(resourceName: "exchange")
        let imageTwo :UIImage = #imageLiteral(resourceName: "indexPhone")
        let imageThree :UIImage = #imageLiteral(resourceName: "indexCheer")
        let imageFour :UIImage = #imageLiteral(resourceName: "indexTrade")
        let imageFive :UIImage = #imageLiteral(resourceName: "indexWashMachine")

        //add image to array
        imagesArray = [imageOne,imageTwo,imageThree,imageFour,imageFive]
    

    override func didReceiveMemoryWarning() 
        super.didReceiveMemoryWarning()
        // Dispose of any resources that can be recreated.
    


    //Action for Button
    @IBAction func randomSelect(_ sender: Any) 
        //temporary array for images
        var tempImageArray = imagesArray

        for imageView in imageViews
        // get random index for array images
        let index = Int(arc4random_uniform(UInt32(tempImageArray.count)))
         // set random image for ImageView
         imageView.image = tempImageArray[index]
         // remove arleady added Image from temporary array
         tempImageArray.remove(at: index)



        
    

针对目标-C

@interface ViewController ()
//array with ImageView
@property (strong, nonatomic) IBOutletCollection(UIImageView) NSArray *imageViews;
//array with Image
@property (strong, nonatomic) NSArray* imagesArray;

- (IBAction)randomSelect:(id)sender;

@end

@implementation ViewController

- (void)viewDidLoad 
    [super viewDidLoad];
     //initiate image
    UIImage *imageOne = [UIImage imageNamed:@"exchange"];
    UIImage *imageTwo = [UIImage imageNamed:@"indexCheer"];
    UIImage *imageThree = [UIImage imageNamed:@"indexPhone"];
    UIImage *imageFour = [UIImage imageNamed:@"indexTrade"];
    UIImage *imageFive = [UIImage imageNamed:@"indexWashMachine"];

    //Initiate array with image
    self.imagesArray = [NSArray arrayWithObjects:imageOne,imageTwo,imageThree,imageFour,imageFive, nil];

    // Do any additional setup after loading the view, typically from a nib.



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



- (IBAction)randomSelect:(id)sender 
    //temporary array for images
    NSMutableArray* tempImageArray = [[NSMutableArray alloc]initWithArray:self.imagesArray];

    for (UIImageView* imageView in self.imageViews)
        // get random index for array images
        int index = arc4random()%(tempImageArray.count-1);
        // set random image for ImageView
        imageView.image = [tempImageArray objectAtIndex:index];
        // remove arleady added Image from temporary array
        [tempImageArray removeObjectAtIndex:index];
    

【讨论】：

我需要objective-c

5分钟，我正在为obj-c重新制作

我有 6 个 UIImageview 那么如何设置

您的 Image 数量大于 ImageView 的数量？

如果计算 imageView 是否超过 Image ，请评论此行“[tempImageArray removeObjectAtIndex:index]”