框架名為：UIImage+WebCache.h 繼承於UIimageView

框架裡面加載網絡圖片的方法共4中：分別為1.普通加載 2.線程NSThread 3.

 

#import "ViewController.h"

#import "UIImage+WebCache.h"

@interface ViewController ()

 

@end

 

@implementation ViewController

 

- (void)viewDidLoad {

[super viewDidLoad];

 

imageArray = [NSMutableArray array];

for(int i = 0;i < 5;i++){

for(int j = 0;j < 6;j++){

UIImageView *imageView = [[UIImageView alloc] initWithFrame:CGRectMake(j*65 +5, i*64 +10, 60, 60)];

imageView.backgroundColor = [UIColor cyanColor];

[self.view addSubview:imageView];

 

[imageArray addObject:imageView];

}

 

}

 

 

UIButton *button = [UIButton buttonWithType:UIButtonTypeRoundedRect];

button.frame = CGRectMake(160, 400, 80, 30);

 

[button setTitle:@"載入" forState:UIControlStateNormal];

[button addTarget:self action:@selector(buttonAction) forControlEvents:UIControlEventTouchUpInside];

 

[self.view addSubview:button];

 

}

- (void)buttonAction{

 

for(UIImageView *imageView in imageArray){

NSString *string = @"http://img3.douban.com/view/photo/photo/public/p2221339563.jpg";

 

NSURL *url = [NSURL URLWithString:string];

 

[imageView setImageWithURL:url];

}

}

UIImage+WebCache.h 自定義一個方法

 

 

#import

 

@interface UIImageView (WebCache)

 

- (void)setImageWithURL:(NSURL *)url;

@end

UIImage+WebCache.m-------- 方法的實現

 

 

#import "UIImage+WebCache.h"

 

@implementation UIImageView (WebCache)

 

- (void)setImageWithURL:(NSURL *)url{

 

//第一種方法：普通的加載

/*

NSData *data = [NSData dataWithContentsOfURL:url];

UIImage *image = [UIImage imageWithData:data];

[self setImage:image];

*/

 

//第二種方法：線程

//NSThread *thread = [[NSThread alloc] initWithTarget:self selector:@selector(loadImage:) object:url];

 

//[thread start];

 

//第三種方法：隊列

/* NSOperationQueue *queue = [[NSOperationQueue alloc] init];

//操作數

NSBlockOperation *op = [NSBlockOperation blockOperationWithBlock:^{

 

NSData *data = [NSData dataWithContentsOfURL:url];

UIImage *image = [UIImage imageWithData:data];

 

//使用主隊列來回到主線程

//在主線程上修改UI

[[NSOperationQueue mainQueue] addOperationWithBlock:^{

//修改UI界面

[self setImage:image];

}];

}];

 

[queue addOperation:op];

*/

 

//----------------GCD---------------

// //1.創建Queue

// dispatch_queue_t queue = dispatch_queue_create("com.xw.gcd.queue", DISPATCH_QUEUE_CONCURRENT);//並行隊列

//

// //2.創建要執行的任務，加到隊列中

// dispatch_async(queue, ^{

//

// NSData *data = [NSData dataWithContentsOfURL:url];

// UIImage *image = [UIImage imageWithData:data];

// [self setImage:image];

// });

 

 

//用系統給的queue---

// (兩個參數)

//參數1：優先級

//參數2：標識符

dispatch_queue_t globalQueue = dispatch_get_global_queue(DISPATCH_QUEUE_PRIORITY_DEFAULT, 0);

 

dispatch_async(globalQueue, ^{

//請求數據

NSData *data = [NSData dataWithContentsOfURL:url];

UIImage *image = [UIImage imageWithData:data];

 

//顯示在UI界面上

dispatch_async(dispatch_get_main_queue(), ^{

//UI相關的代碼

//UI界面的刷新最好回到主線程中

[self setImage:image];

});

});

 

}

 

- (void)loadImage:(NSURL *)url{

NSData *data = [NSData dataWithContentsOfURL:url];

UIImage *image = [UIImage imageWithData:data];

[self setImage:image];

 

 

}

@end