图片加载

#import <UIKit/UIKit.h>

@interface ViewController : UIViewController<NSURLConnectionDataDelegate>
@property (strong, nonatomic) IBOutlet UIImageView *imageview;
@property(nonatomic,strong)NSMutableData *recedate;
- (IBAction)Done:(id)sender;

- (IBAction)ShouCang:(id)sender;

@end

#import "ViewController.h"

@interface ViewController ()

@end





@implementation ViewController

- (void)viewDidLoad {
    _recedate =[[NSMutableData alloc]init];
    
    [super viewDidLoad];
    // Do any additional setup after loading the view, typically from a nib.
}

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


- (IBAction)Done:(id)sender
{
    NSString *urlAsString=@"http://gaitaobao1.alicdn.com/tfscom/TB10NzeHXXXXXcFXVXXXXXXXXXX.jpg_180x180xz.jpg";
//    NSURL *url=[NSURL URLWithString:urlAsString];
//    NSURLRequest *urlRequest=[NSURLRequest requestWithURL:url];
//   不可变
//    [NSURLConnection connectionWithRequest:urlRequest delegate:self];
    
    
    NSURL *url=[NSURL URLWithString:urlAsString];
    NSMutableURLRequest *urlRequest=[NSMutableURLRequest requestWithURL:url];
   //可变
    [NSURLConnection connectionWithRequest:urlRequest delegate:self];
    
}
- (void)connection:(NSURLConnection *)connection didReceiveData:(NSData *)data
{
   [_recedate appendData:data];
    NSLog(@"走近");
}
- (void)connectionDidFinishLoading:(NSURLConnection *)connection
{
    UIImage *image=[UIImage imageWithData:_recedate];
    self.imageview.image=image;
}
- (IBAction)ShouCang:(id)sender {
}
@end
第二部分
#import "ViewController.h"

@interface ViewController ()

@end

@implementation ViewController

- (void)viewDidLoad {
    [super viewDidLoad];
    // Do any additional setup after loading the view, typically from a nib.
}

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


- (IBAction)Done:(id)sender {
    
    UIImage *image=nil;
    NSString *urlAsString=@"http://gaitaobao1.alicdn.com/tfscom/TB10NzeHXXXXXcFXVXXXXXXXXXX.jpg_180x180xz.jpg";
    NSURL *url=[NSURL URLWithString:urlAsString];
    NSURLRequest *urlRequest=[NSURLRequest requestWithURL:url];
    
    NSError *err=nil;
    NSData *imagedate=[NSURLConnection sendSynchronousRequest:urlRequest returningResponse:nil error:&err];
    //这个线程休眠5秒
    //
    [NSThread sleepForTimeInterval:5];
    if (err==nil&&imagedate!=nil) {
        image=[UIImage imageWithData:imagedate];
    }
    else if (err!=nil)
    {
        NSLog(@"error ==%@",err);
    }
     self.imageview.image=image;
    
    
}

- (IBAction)ShouCang:(id)sender {
}
@end