iOS 開發之 為UIButton添加類別方法載入網狀圖片

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iOS 開發之 為UIButton添加類別方法載入網狀圖片

 

使用GCD線程隊列實現

 

工程如下:

 

UIButton+WebCache.h

 

#import <UIKit/UIKit.h>

 

 

// 為Button添加類別方法

 

@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];

    

    // 根據圖片的url下載圖片資料

    

    dispatch_queue_t xrQueue = dispatch_queue_create("loadImage", NULL); // 建立GCD線程隊列

    

    dispatch_async(xrQueue, ^{

       

        // 非同步下載圖片

        

        UIImage * img = [UIImage imageWithData:[NSData dataWithContentsOfURL:url]];

        

        // 主線程重新整理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

 

:

 

 

iOS 開發之 為UIButton添加類別方法載入網狀圖片