AFNetworking的使用

1.下载AFNetworking资源包 https://github.com/AFNetworking/AFNetworking。

2.将资源包添加到工程文件。

3.在工程的Supporting File群组中打开预编译头文件XXX-Prefix.pch。然后在别的import后面添加如下一行代码#import “AFNetworking”

将AFNetworking添加到预编译头文件，意味着这个框架会被自动的添加到工程的所有源代码文件中。

4.AFNetworking通过网络来加载和处理结构化的数据非常明智，它支持JSON,XML,Property List。

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1. static NSString*const BaseURLString = @"http://www.raywenderlich.com/downloads/weather_sample/";

2.  

3. // 1

4. NSString *weatherUrl = [NSStringstringWithFormat:@"%@weather.php?format=json",BaseURLString];

5. NSURL *url = [NSURLURLWithString:weatherUrl];

6. NSURLRequest *request = [NSURLRequestrequestWithURL:url];

7.  

8. // 2

9. AFJSONRequestOperation *operation =

10. [AFJSONRequestOperationJSONRequestOperationWithRequest:request

11. success:^(NSURLRequest*request, NSHTTPURLResponse *response, id JSON) {

12. //

13. NSDictionary*dicWeather = (NSDictionary *)JSON;

14. NSLog(@"result:%@",dicWeather);

15. }

16. failure:^(NSURLRequest*request, NSHTTPURLResponse *response, NSError *error, id JSON) {

17. UIAlertView*alertView = [[UIAlertView alloc] initWithTitle:@"Error RetrievingWeather"

18. message:[NSStringstringWithFormat:@"%@",error]

19. delegate:self

20. cancelButtonTitle:@"OK"

21. otherButtonTitles: nil];

22. [alertView show];

23. }];

24. // 5

25. [operation start];

static NSString*const BaseURLString = @"http://www.raywenderlich.com/downloads/weather_sample/";
   
    // 1
    NSString *weatherUrl = [NSStringstringWithFormat:@"%@weather.php?format=json",BaseURLString];
    NSURL *url = [NSURLURLWithString:weatherUrl];
    NSURLRequest *request = [NSURLRequestrequestWithURL:url];
   
    // 2
    AFJSONRequestOperation *operation =
    [AFJSONRequestOperationJSONRequestOperationWithRequest:request
                                              success:^(NSURLRequest*request, NSHTTPURLResponse *response, id JSON) {
                                                 //
                                                 NSDictionary*dicWeather = (NSDictionary *)JSON;
                                                 NSLog(@"result:%@",dicWeather);
                                              }
                                              failure:^(NSURLRequest*request, NSHTTPURLResponse *response, NSError *error, id JSON) {
                                                 UIAlertView*alertView = [[UIAlertView alloc] initWithTitle:@"Error RetrievingWeather"
                                                                                               message:[NSStringstringWithFormat:@"%@",error]
                                                                                              delegate:self
                                                                                      cancelButtonTitle:@"OK"
                                                                                      otherButtonTitles: nil];
                                                 [alertView show];
                                              }];
    // 5
    [operation start];

(1)根据基本的URL构造除完整的一个URL，然后通过这个完整的URL获得一个NSURL对象，然后根据这个url获得一个NSURLRequest。

(2)AFJSONRequestOperation是一个完整的类，整合了从网络中获取数据并对JSON进行解析。

(3)当请求成功，则运行成功块。在本例中，把解析出来的天气数据从JSON变量转换为一个字典(dictionary)，并将其存储在字典中。

(4)如果运行出问题了，则运行失败块(failure block)，比如网络不可用。如果failure block被调用了，将会通过提示框显示错误信息。

6.AFNetWorking异步加载图片

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1. (1)#import “UIImageView+AFNetworking.h”

2. (2)UIImageView *imageView = [[UIImageView alloc]initWithFrame:CGRectMake(40, 80, 40, 40)];

3. __weak UIImageView *_imageView = imageView;

4. [imageViewsetImageWithURLRequest:[[NSURLRequest alloc] initWithURL:[NSURLURLWithString:@"http://www.worldweatheronline.com/images/wsymbols01_png_64/wsymbol_0001_sunny.png"]]

5. placeholderImage:[UIImage imageNamed:@"placeholder.png"]

6. success:^(NSURLRequest *request,NSHTTPURLResponse *response, UIImage *image) {

7. _imageView.image = image;

8.  

9. [_imageView setNeedsDisplay];

10. }

11. failure:^(NSURLRequest *request, NSHTTPURLResponse*response, NSError *error) {

12. ;

13. }];

14. [self.view addSubview:imageView];

(1)#import “UIImageView+AFNetworking.h”
(2)UIImageView *imageView = [[UIImageView alloc]initWithFrame:CGRectMake(40, 80, 40, 40)];
    __weak UIImageView *_imageView = imageView;
    [imageViewsetImageWithURLRequest:[[NSURLRequest alloc] initWithURL:[NSURLURLWithString:@"http://www.worldweatheronline.com/images/wsymbols01_png_64/wsymbol_0001_sunny.png"]]
                   placeholderImage:[UIImage imageNamed:@"placeholder.png"]
                           success:^(NSURLRequest *request,NSHTTPURLResponse *response, UIImage *image) {
                              _imageView.image = image;
                             
                              [_imageView setNeedsDisplay];
                           }
                           failure:^(NSURLRequest *request, NSHTTPURLResponse*response, NSError *error) {
                              ;
                           }];
    [self.view addSubview:imageView];

7.GET 和POST请求

(1).构建一个baseURL，以及一个参数字典，并将这两个变量传给AFHTTPClient.

(2).将AFJSONRequestOperation注册为HTTP的操作, 这样就可以跟之前的示例一样，可以获得解析好的JSON数据。

(3).做了一个GET请求，这个请求有一对block：success和failure。

(4).POST请求跟GET一样

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1. AFHTTPClient *client= [[AFHTTPClient alloc] initWithBaseURL:baseURL];

2. [clientregisterHTTPOperationClass:[AFJSONRequestOperation class]];

3. [clientsetDefaultHeader:@"Accept" value:@"application/json"];

4. [client postPath:@"weather.php"

5. parameters:parameters

6. success:^(AFHTTPRequestOperation *operation, id responseObject) {

7. self.weather =responseObject;

8. self.title = @"HTTPPOST";

9. [self.tableViewreloadData];

10. }

11. failure:^(AFHTTPRequestOperation *operation, NSError*error) {

12. UIAlertView *av =[[UIAlertView alloc] initWithTitle:@"Error Retrieving Weather"

13. message:[NSStringstringWithFormat:@"%@",error]

14. delegate:nil

15. cancelButtonTitle:@"OK" otherButtonTitles:nil];

16. [av show];

17.  

18. }

19. ];

20.  

21. [client getPath:@"weather.php"

22. parameters:parameters

23. success:^(AFHTTPRequestOperation *operation, id responseObject) {

24. self.weather =responseObject;

25. self.title = @"HTTP GET";

26. [self.tableViewreloadData];

27. }

28. failure:^(AFHTTPRequestOperation *operation, NSError*error) {

29. UIAlertView *av =[[UIAlertView alloc] initWithTitle:@"Error Retrieving Weather"

30. message:[NSStringstringWithFormat:@"%@",error]

31. delegate:nil

32. cancelButtonTitle:@"OK" otherButtonTitles:nil];

33. [av show];

34.  

35. }

36. ];

AFHTTPClient *client= [[AFHTTPClient alloc] initWithBaseURL:baseURL];
[clientregisterHTTPOperationClass:[AFJSONRequestOperation class]];
[clientsetDefaultHeader:@"Accept" value:@"application/json"];
[client postPath:@"weather.php"
              parameters:parameters
                success:^(AFHTTPRequestOperation *operation, id responseObject) {
                     self.weather =responseObject;
                     self.title = @"HTTPPOST";
                     [self.tableViewreloadData];
                 }
                failure:^(AFHTTPRequestOperation *operation, NSError*error) {
                     UIAlertView *av =[[UIAlertView alloc] initWithTitle:@"Error Retrieving Weather"
                                                                 message:[NSStringstringWithFormat:@"%@",error]
                                                                delegate:nil
                                                       cancelButtonTitle:@"OK" otherButtonTitles:nil];
                     [av show];
 
                 }
         ];
 
[client getPath:@"weather.php"
             parameters:parameters
               success:^(AFHTTPRequestOperation *operation, id responseObject) {
                    self.weather =responseObject;
                    self.title = @"HTTP GET";
                    [self.tableViewreloadData];
                }
               failure:^(AFHTTPRequestOperation *operation, NSError*error) {
                    UIAlertView *av =[[UIAlertView alloc] initWithTitle:@"Error Retrieving Weather"
                                                                 message:[NSStringstringWithFormat:@"%@",error]
                                                               delegate:nil
                                                      cancelButtonTitle:@"OK" otherButtonTitles:nil];
                    [av show];
 
                }
         ];

8.AFNetworking更新背景图片

Note:

AFJSONOperation,AFPropertyListOperation, AFXMLOperation用来解析结构化数据。

UIImageView+AFNetworking用来快捷的填充image view

AFHTTPClient用来进行更底层的请求

用自定义的AFHTTPClient子类来访问一个web service。

AFNetworkActivityIndicatiorManager用来给用户做出网络访问的提示。

AFImageRequestOperation用来加载图片。