Question

我有一个属性的视图应该从我的视图控制器获取NSString并显示图像。如果我在视图中使用“320x213-1.png”对locationImageFile进行硬编码，则图像显示正常，但如果我尝试从视图控制器设置locationImageFile，则不会显示图像。我觉得我错过了一些非常基本的东西。旁注：我似乎能够从我的视图控制器中设置locationTitle属性而没有任何问题。

LocationViewController.m

#import "LocationViewController.h"
#import "LocationView.h"

@implementation LocationViewController
{
    LocationView *_locationView;
}

- (void)loadView
{
    CGRect frame = [[UIScreen mainScreen] bounds];
    _locationView = [[LocationView alloc] initWithFrame:frame];
    [self setView:_locationView];
}

- (void)viewDidLoad
{
    [super viewDidLoad];

    // Do any additional setup after loading the view.

    _locationView.locationTitle.text = aLocation.name;
    _locationView.locationImageFile = @"320x213-1.png";

}

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

@end

LocationView.m

#import "LocationView.h"

@implementation LocationView

@synthesize locationTitle;
@synthesize locationImageFile;


- (id)initWithFrame:(CGRect)frame
{
    self = [super initWithFrame:frame];
    if (self) {
        // Initialization code

        [self setBackgroundColor: [UIColor blueColor]];

        // Image container
        UIImage *locationImage = [UIImage imageNamed:locationImageFile];
        UIImageView *locationImageContainer = [[UIImageView alloc] initWithImage:locationImage];
        [locationImageContainer setTranslatesAutoresizingMaskIntoConstraints:NO];
        locationImageContainer.backgroundColor = [UIColor yellowColor];
        [self addSubview:locationImageContainer];

        // Text line
        locationTitle = [[UILabel alloc]init];
        [locationTitle setTranslatesAutoresizingMaskIntoConstraints:NO];
        locationTitle.backgroundColor = [UIColor whiteColor];
        [self addSubview:locationTitle];

        }
    return self;
}

@end

Answer 1

初始化LocationView时，实例变量locationImageFile的值等于nil。覆盖locationImageFile内的LocationView.m属性的setter，如下所示：

- (void)setLocationImageFile:(NSString *)aLocationImageFile
{
    locationImageFile = aLocationImageFile;
    locationImageContainer.image = [UIImage imageNamed:aLocationImageFile];
}

Answer 2

我认为这是因为loadView方法比viewDidLoad方法更早调用。

因此，当您设置_locationView.locationImageFile = @"320x213-1.png";时，未设置containerView的图像。

您可以考虑将locationImageContainer声明为locationView的属性，并直接设置它的图像。赞。

_locationView.locationImageContainer.image = [UIImage imageNamed:@"320x213-1.png"];

而不是将locationImageFile设置为属性。

Answer 3

您可以尝试这样做：

_locationView.locationImageFile = [UIImage imageNamed:locationImageFile];

如果你这样做： _locationView.locationImageFile = locationImageFile;

iOS无法以编程方式加载图像文件以从视图控制器进行查看

3 个答案: