NSString类方法同步请求、使用NSData方法同步请求 下载图片、数据

#import "ViewController.h"

@interface ViewController ()

@property(nonatomic,weak)IBOutlet UIButton *button;

@property(nonatomic,weak)IBOutlet UIImageView *imageView;

@end

@implementation ViewController

-(IBAction)btnClick:(id)sender
{
//给一个url字符串
NSString *str = @"http://iappfree.candou.com:8080/free/applications/limited?currency=rmb&page=3";

NSString *str2 = @"http://photo.candou.com/i/114/826ea823e8ffe792a6fda9e126f6c404";
//封装成可用的URL类型;
NSURL *url = [NSURL URLWithString:str];
NSURL *url2 = [NSURL URLWithString:str2];

[self syncDownloadWithString:url];
[self syncDownloadWithData:url2];
}

#pragma mark -NSData类方法的同步请求-

-(void)syncDownloadWithData:(NSURL *)url{
//二进制数据提供的同步请求方法
NSData *data = [NSData dataWithContentsOfURL:url];

//NSData -->UIImage
UIImage *image = [UIImage imageWithData:data];

//UIImage -->NSData
NSData *dataImage = UIImagePNGRepresentation(image);
NSData *dataImage2 = UIImageJPEGRepresentation(image, 0.5);
UIImage *image3 = [UIImage imageWithContentsOfFile:@""];

self.imageView.image = image;

NSLog(@"下载完毕");
}

#pragma mark -NSString类方法的同步请求-
-(void)syncDownloadWithString:(NSURL *)url{

//字符串提供的同步请求的方法
NSError *error;
NSString *str = [[NSString alloc]initWithContentsOfURL:url encoding:NSUTF8StringEncoding error:&error];
if (error) {
NSLog(@"%@",error);
return;
}
//NSString --->NSData;
NSData *data = [str dataUsingEncoding:NSUTF8StringEncoding];

//NSDate -->NSString
NSString *strData = [[NSString alloc]initWithData:data encoding:NSUTF8StringEncoding];
NSLog(@"%@",strData);

NSDictionary * dict = [NSJSONSerialization JSONObjectWithData:data options:NSJSONReadingMutableContainers error:nil];
NSLog(@"%@",dict);

NSLog(@"str:%@",str);
}
- (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.
}