iOS网络编程笔记——编写自己的网络客户端

编写网络客户端主要有四个步骤：

（1）项目中引入Accounts和Social框架

Accounts框架中有进行用户账户认证所需类，Social框架提供了我们所需要的SLRequest类。

（2）用户账户认证

用户账户认证使用ACAccount、ACAccountStore和ACAccountType类，ACAccount类是封装用户账户信息，这些信息存储在账户数据库中。ACAccountStore类用来管理用户账户数据库，ACAccountType类用来描述账户类型。

（3）发送请求

用户认证通过就可以进行发送，使用SLRequest对象发送请求。

（4）处理请求结果

处理请求结果，解析数据更新ui

具体代码使用通过一个新浪微博例子：

微博列表类：

#import "WeiboListController.h"
#import <Social/Social.h>
#import <Accounts/Accounts.h>

#define WEIBO_LIST @"https://api.weibo.com/2/statuses/user_timeline.json"

@interface WeiboListController ()
/*
 * 返回的微博列表
 */
@property (nonatomic, strong) NSArray *listData;

@end

@implementation WeiboListController

- (void)viewDidLoad {
    [super viewDidLoad];
    //初始化UIRefreshControl
    UIRefreshControl *rc = [[UIRefreshControl alloc] init];
    rc.attributedTitle = [[NSAttributedString alloc] initWithString:@"下拉刷新"];
    [rc addTarget:self action:@selector(refreshTableView) forControlEvents:UIControlEventValueChanged];
    self.refreshControl = rc;
}

- (void)refreshTableView
{
    if (self.refreshControl.isRefreshing){
        self.refreshControl.attributedTitle = [[NSAttributedString alloc] initWithString:@"加载中..."];
        //创建一个ACAccountStore对象用来查询用户信息
        ACAccountStore *account = [[ACAccountStore alloc] init];
        //获得ACAccountType对象，参数为账户类型标识
        ACAccountType *accountType = [account accountTypeWithAccountTypeIdentifier:ACAccountTypeIdentifierSinaWeibo];
        //请求访问用户账户信息,请求完成回调代码块
        [account requestAccessToAccountsWithType:accountType options:nil completion:^(BOOL granted, NSError *error) {
            if (granted == YES){//认证通过
                //返回所有特定类型标识账户信息
                NSArray *arrayOfAccounts = [account accountsWithAccountType:accountType];
                if ([arrayOfAccounts count] > ) {
                    ACAccount *weiboAccount = [arrayOfAccounts lastObject];
                    //设置请求参数  由社交网站提供
                    NSDictionary *parameters = [NSDictionary dictionaryWithObject:@"" forKey:@"count"];
                    NSURL *requestURL = [NSURL URLWithString:WEIBO_LIST];
                    //发送请求
                    SLRequest *request = [SLRequest requestForServiceType:SLServiceTypeSinaWeibo requestMethod:SLRequestMethodGET URL:requestURL parameters:parameters];
                    request.account = weiboAccount;//为请求对象设置账户信息
                    [request performRequestWithHandler:^(NSData *responseData, NSHTTPURLResponse *urlResponse, NSError *error) {
                       //处理请求结果
                        NSError *err;
                        if (!responseData){
                            return ;
                        }
                        id jsonObj = [NSJSONSerialization JSONObjectWithData:responseData options:NSJSONReadingAllowFragments error:&err];
                        if (!err) {
                            _listData = [jsonObj objectForKey:@"statuses"];
                            [self.tableView reloadData];
                        }
                        //停止下拉刷新
                        if (self.refreshControl) {
                            [self.refreshControl endRefreshing];
                            self.refreshControl.attributedTitle = [[NSAttributedString alloc] initWithString:@"下拉刷新"];
                        }
                    }];
                }
            }
        }];
    }
}

#pragma mark - Table view data source

- (NSInteger)tableView:(UITableView *)tableView numberOfRowsInSection:(NSInteger)section {
    return self.listData.count;
}

- (UITableViewCell *)tableView:(UITableView *)tableView cellForRowAtIndexPath:(NSIndexPath *)indexPath
{
    UITableViewCell *cell = [tableView dequeueReusableCellWithIdentifier:@"Cell"];
    NSDictionary *dict = self.listData[indexPath.row];
    cell.textLabel.text = [dict objectForKey:@"text"];
    cell.detailTextLabel.text = [dict objectForKey:@"created_at"];
    return cell;
}

@end

微博发送类：

//
//  WeiboSendController.m
//  Weibo
//
//  Created by 王凯 on 17/3/1.
//  Copyright © 2017年 王凯. All rights reserved.
//

#import "WeiboSendController.h"
#import <Social/Social.h>
#import <Accounts/Accounts.h>

@interface WeiboSendController ()<UITextViewDelegate>
@property (weak, nonatomic) IBOutlet UITextView *textView;
@property (weak, nonatomic) IBOutlet UILabel *countLabel;

@end

@implementation WeiboSendController

- (void)viewDidLoad {
    [super viewDidLoad];
}

#pragma mark -<UITextViewDelegate>

- (BOOL)textView:(UITextView *)textView shouldChangeTextInRange:(NSRange)range replacementText:(NSString *)text
{
    NSString *content = _textView.text;
    NSInteger count =  - [content length];
    if (count < ) {
        _countLabel.text = @"";
        return NO;
    }
    _countLabel.text = [NSString stringWithFormat:@"%ld",count];
    return YES;
}

- (IBAction)sendBtnClick:(id)sender {
    ACAccountStore *account = [[ACAccountStore alloc] init];
    ACAccountType *accountType = [account accountTypeWithAccountTypeIdentifier:ACAccountTypeIdentifierSinaWeibo];
    [account requestAccessToAccountsWithType:accountType options:nil completion:^(BOOL granted, NSError *error) {
        if (granted == YES) {
            NSArray *arrayOfAccounts = [account accountsWithAccountType:accountType];
            if ([arrayOfAccounts count] > ) {
                ACAccount *weiboAccount = [arrayOfAccounts lastObject];
                NSDictionary *parameters = [NSDictionary dictionaryWithObject:_textView.text forKey:@"status"];
                NSURL *requestURL = [NSURL URLWithString:@"https://api.weibo.com/2/statuses/update.json"];
                SLRequest *request = [SLRequest requestForServiceType:SLServiceTypeSinaWeibo requestMethod:SLRequestMethodPOST URL:requestURL parameters:parameters];
                request.account = weiboAccount;
                [request performRequestWithHandler:^(NSData *responseData, NSHTTPURLResponse *urlResponse, NSError *error) {
                    NSLog(@"weibo http response:%ld",[urlResponse statusCode]);
                }];
            }
        }
    }];
    //放弃第一响应者
    [_textView resignFirstResponder];
    //关闭模态视图
    [self dismissViewControllerAnimated:YES completion:nil];
}

- (IBAction)cancelBtnClick:(id)sender {
    //放弃第一响应者
    [_textView resignFirstResponder];
    //关闭模态视图
    [self dismissViewControllerAnimated:YES completion:nil];
}