【代碼筆記】iOS-HTTPQueue下載圖片

一，工程圖。

二，代碼。

ViewController.h

#import <UIKit/UIKit.h>
#import "ASIHTTPRequest.h"
#import "ASINetworkQueue.h"
#import "NSNumber+Message.h"
#import "NSString+URLEncoding.h"


@interface ViewController : UIViewController
@property (nonatomic,strong) ASINetworkQueue  *networkQueue;

@end

ViewController.m

//ASINetworkQueue下載圖片
#import "ViewController.h"

@interface ViewController ()

@end

@implementation ViewController

- (void)viewDidLoad {
    [super viewDidLoad];
    // Do any additional setup after loading the view, typically from a nib.
}
//點擊任何處，進行圖片下載
-(void)touchesBegan:(NSSet *)touches withEvent:(UIEvent *)event
{
    if (!_networkQueue) {
        _networkQueue = [[ASINetworkQueue alloc] init];
    }
    
    // 停止以前的隊列
    [_networkQueue cancelAllOperations];
    
    // 創建ASI隊列
    [_networkQueue setDelegate:self];
    [_networkQueue setRequestDidFinishSelector:@selector(requestFinished:)];
    [_networkQueue setRequestDidFailSelector:@selector(requestFailed:)];
    [_networkQueue setQueueDidFinishSelector:@selector(queueFinished:)];
    
    for (int i=1; i<3; i++) {
        NSString *strURL = [[NSString alloc] initWithFormat:@"http://iosbook3.com/service/download.php?email=%@&FileName=test%i.jpg",@"<你的iosbook3.com用戶郵箱>",i];
        NSURL *url = [NSURL URLWithString:[strURL URLEncodedString]];
        ASIHTTPRequest *request = [ASIHTTPRequest requestWithURL:url];
        
        request.tag = i;
        [_networkQueue addOperation:request];
    }
    
    [_networkQueue go];

}
- (void)requestFinished:(ASIHTTPRequest *)request
{
    NSData *data = [request responseData];
    NSError *eror;
    NSDictionary *resDict = [NSJSONSerialization JSONObjectWithData:data options:NSJSONReadingAllowFragments error:&eror];
    
    if (!resDict) {
        UIImage *img = [UIImage imageWithData:data];
        if (request.tag ==1) {
           // _imageView1.image = img;
            NSLog(@"---img--%@",img);
        } else {
            //_imageView2.image = img;
            NSLog(@"---img--%@",img);

        }
    } else {
        NSNumber *resultCodeObj = [resDict objectForKey:@"ResultCode"];
        
        NSString *errorStr = [resultCodeObj errorMessage];
        UIAlertView *alertView = [[UIAlertView alloc] initWithTitle:@"錯誤信息"
                                                            message:errorStr
                                                           delegate:nil
                                                  cancelButtonTitle:@"OK"
                                                  otherButtonTitles: nil];
        [alertView show];
    }
    if ([_networkQueue requestsCount] == 0) {
        [self setNetworkQueue:nil];
    }
    NSLog(@"請求成功");
}

- (void)requestFailed:(ASIHTTPRequest *)request
{
    NSError *error = [request error];
    NSLog(@"%@",[error localizedDescription]);
    if ([_networkQueue requestsCount] == 0) {
        [self setNetworkQueue:nil];
    }
    NSLog(@"請求失敗");
}


- (void)queueFinished:(ASIHTTPRequest *)request
{
    if ([_networkQueue requestsCount] == 0) {
        [self setNetworkQueue:nil];
    }
    NSLog(@"隊列完成");
}


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

@end