ios UIButton ios uibutton加载网络图片

iOS 开发之 为UIButton添加类别方法加载网络图片

 

使用GCD线程队列实现

 

工程如下:

UIButton+WebCache.h
 
#import <UIKit/UIKit.h>
 
 
// 为Button添加类别方法
 
@interface UIButton (WebCache)
 
 
- (void)xr_setButtonImageWithUrl:(NSString *)urlStr;
 
@end
 
UIButton+WebCache.m
 
#import "UIButton+WebCache.h"
 
@implementation UIButton (WebCache)
 
- (void)xr_setButtonImageWithUrl:(NSString *)urlStr {
    
    NSURL * url = [NSURL URLWithString:urlStr];
    
    // 根据图片的url下载图片数据
    
    dispatch_queue_t xrQueue = dispatch_queue_create("loadImage", NULL); // 创建GCD线程队列
    
    dispatch_async(xrQueue, ^{
       
        // 异步下载图片
        
        UIImage * img = [UIImage imageWithData:[NSData dataWithContentsOfURL:url]];
        
        // 主线程刷新UI
        dispatch_async(dispatch_get_main_queue(), ^{
            
            [self setImage:img forState:UIControlStateNormal];
        });
        
    });
}
 
@end
 
 
#import <UIKit/UIKit.h>
 
@interface XRViewController : UIViewController
@property (weak, nonatomic) IBOutlet UIButton *ImgBtn;
 
@end
 
 
#import "XRViewController.h"
#import "UIButton+WebCache.h"
 
@interface XRViewController ()
 
@end
 
@implementation XRViewController
 
- (void)viewDidLoad
{
    [super viewDidLoad];
 // Do any additional setup after loading the view, typically from a nib.
}
 
- (IBAction)loadImg:(id)sender {
    
    [self loadImage];
    
}
 
- (void)loadImage {
    [_ImgBtn xr_setButtonImageWithUrl:@"http://img3.3lian.com/2014/c2/66/d/56.jpg"];
}
 
- (void)didReceiveMemoryWarning
{
    [super didReceiveMemoryWarning];
    // Dispose of any resources that can be recreated.
}
 
@end

 

效果图: