Day.05.03 UIImageView 加载图片

ViewController.m

#import "ViewController.h"
#import "UIImageView+WebImage.h"
@interface ViewController ()

//连线..  在storyboard 创建一个imageView 
@property (weak, nonatomic) IBOutlet UIImageView *imgView;

@end

@implementation ViewController

- (void)viewDidLoad {
    [super viewDidLoad];
    // Do any additional setup after loading the view, typically from a nib.
    
    //图片地址
    [_imgView setImageWithUrl:@"http://banbao.chazidian.com/uploadfile/2016-01-25/s145368924044608.jpg"];
    
}

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

@end

UIImageView+WebImage.h

#import 

@interface UIImageView (WebImage)

-(void)setImageWithUrl:(NSString *)url;

@end

UIImageView+WebImage.m

#import "UIImageView+WebImage.h"

@implementation UIImageView (WebImage)

//根据url设置图片
-(void)setImageWithUrl:(NSString *)url
{
    //第一步：创建子线程
    NSThread *thread = [[NSThread alloc] initWithTarget:self selector:@selector(loadImage:) object:url];
    
    [thread start];
    
}
//获取图片数据
-(void)loadImage:(NSString *)url
{
    //第二步：根据url获取图片数据
    NSData *imgData = [[NSData alloc] initWithContentsOfURL:[NSURL URLWithString:url]];
    
    if (imgData) {
        UIImage *image = [[UIImage alloc] initWithData:imgData];
        
        ///第三步：回到主线程更改图片属性
        [self performSelectorOnMainThread:@selector(setImage:) withObject:image waitUntilDone:nil];    
    }
}

@end

屏幕快照 2016-05-03 下午7.54.17.png