前言
1.网络请求
系统请求的方法
分为get请求和post请求
1.1、get请求系统提供了两种方法，一种是Request方式的，一种是URL方式的。下面先说request方式的
NSString * urlStr = @"http://172.16.101.125:8080/wisdombus-controller/mobile/class/queryBusLineList?corpId=0";
NSURL * url = [NSURL URLWithString:urlStr];
NSURLSession * senssion = [NSURLSession sharedSession];//网络请求管理者
NSMutableURLRequest * request = [NSMutableURLRequest requestWithURL:url];//创建请求对象
//创建网络数据请求任务的对象
NSURLSessionDataTask * task1 = [senssion dataTaskWithRequest:request completionHandler:^(NSData * _Nullable data, NSURLResponse * _Nullable response, NSError * _Nullable error) {
//由NSData对象获取json字符串
NSString * string = [[NSString alloc] initWithData:data encoding:NSUTF8StringEncoding];
NSLog(@"%@",string);
//NSData数据转字典
NSDictionary * dic = [NSJSONSerialization JSONObjectWithData:data options:0 error:nil];
NSLog(@"%@",dic);
//回到主线程
[self performSelector:@selector(actionWithString:) onThread:[NSThread mainThread] withObject:string waitUntilDone:YES];
}];
[task1 resume];
get请求url方式
NSString * urlStr = @"http://172.16.101.125:8080/wisdombus-controller/mobile/class/queryBusLineList?corpId=0";
NSURL * url = [NSURL URLWithString:urlStr];
//网络请求管理者
NSURLSession * senssion = [NSURLSession sharedSession];
//创建网络数据请求任务的对象
NSURLSessionDataTask * task2 = [senssion dataTaskWithURL:url completionHandler:^(NSData * _Nullable data, NSURLResponse * _Nullable response, NSError * _Nullable error) {
//获取json字符串
NSString * string = [[NSString alloc] initWithData:data encoding:NSUTF8StringEncoding];
NSLog(@"%@",string);
}];
[task2 resume];
1.2、post请求
NSString * urlStr = @"http://172.16.101.125:8080/wisdombus-controller/mobile/class/queryBusLineList";
NSURL * url = [NSURL URLWithString:urlStr];
NSURLSession * senssion = [NSURLSession sharedSession];//网络请求管理者
NSMutableURLRequest * Postrequest = [NSMutableURLRequest requestWithURL:url];
Postrequest.HTTPMethod = @"POST";
//设置包体
Postrequest.HTTPBody = [@"username=520it&pwd=520it" dataUsingEncoding:NSUTF8StringEncoding];
//创建任务
NSURLSessionDataTask * task = [senssion dataTaskWithRequest:Postrequest completionHandler:^(NSData * _Nullable data, NSURLResponse * _Nullable response, NSError * _Nullable error) {
NSLog(@"%@",[NSJSONSerialization JSONObjectWithData:data options:0 error:nil]);
NSString * string = [[NSString alloc] initWithData:data encoding:NSUTF8StringEncoding];
[self performSelector:@selector(actionWithString:) onThread:[NSThread mainThread] withObject:string waitUntilDone:YES];
}];
[task resume];
第三方网络请求--AFNetWorking
在使用网络请求的控制器中引入头文件
#import <AFNetworking/AFNetworking.h>
创建请求管理者，并设置相关属性
//创建请求管理者
AFHTTPSessionManager * sessionManager = [AFHTTPSessionManager manager];
//上传设置
sessionManager.requestSerializer = [AFHTTPRequestSerializer serializer];//普通格式上传
//sessionManager.requestSerializer = [AFJSONRequestSerializer serializer]; // 上传JSON格式
sessionManager.requestSerializer.timeoutInterval = 10.0f;
//返回数据设置
sessionManager.responseSerializer = [AFHTTPResponseSerializer serializer];//自己动手解析
//sessionManager.responseSerializer = [AFJSONResponseSerializer serializer]; // AFN会JSON解析返回的数据
// 个人建议还是自己解析的比较好，有时接口返回的数据不合格会报3840错误，大致是AFN无法解析返回来的数据
sessionManager.responseSerializer.acceptableContentTypes = [NSSet setWithObjects:@"text/plain", @"text/json", @"application/json", @"text/javascript", @"text/html",@"charset=utf-8", nil];
//创建参数和参数值字典
NSDictionary * dic = @{@"corpId":@"0"};
NSString * urlString = @"http://172.16.101.125:8080/wisdombus-controller/mobile/class/queryBusLineList";
post请求
[sessionManager POST:urlString parameters:dic progress:nil success:^(NSURLSessionDataTask * _Nonnull task, id _Nullable responseObject) {
NSLog(@"%@",responseObject);
self.textView2.text = [NSString stringWithFormat:@"%@",responseObject];
} failure:^(NSURLSessionDataTask * _Nullable task, NSError * _Nonnull error) {
NSLog(@"%@",error);
}];
get请求
[sessionManager GET:urlString parameters:dic progress:^(NSProgress * _Nonnull downloadProgress) {
} success:^(NSURLSessionDataTask * _Nonnull task, id _Nullable responseObject) {
NSLog(@"%@",responseObject);
self.textView2.text = [NSString stringWithFormat:@"%@",responseObject];
} failure:^(NSURLSessionDataTask * _Nullable task, NSError * _Nonnull error) {
NSLog(@"%@",error);
}];
注意：系统的网络请求的block中请求改变外部变量需要做特殊处理，但是第三方的不需要
2.获取数据，并处理数据
对于数据的处理主要是两种：
一种是NSData转json字符串
NSString * string = [[NSString alloc] initWithData:data encoding:NSUTF8StringEncoding];
一种是NSData数据转字典
NSDictionary * dic = [NSJSONSerialization JSONObjectWithData:data options:0 error:nil];
3.获取导数据后的非空处理
对于获取到的数据，如果不做非空处理，很容易出现数组越界的情况。所以必须得处理，但是不同的后台开发人员，写的接口字段非空时返回的形式多种多样，所以要综合处理多种情况，才能避免出错。
1、对于数组对象，需要判断元素的个数和数组是否为空
if (self.busLineArr.count == 0||self.busLineArr == nil) {
[self showErrorMessage:@"暂时不能进行切换"];
return;
}
2、对于字符串对象，需要判断nil、NSNull对象、@“”、@“null”,等4种情况
if (([str isKindOfClass:[NSNull class]]||str == nil||[[NSString stringWithFormat:@"%@",str] length] < 1||[[NSString stringWithFormat:@"%@",str] isEqualToString:@"(null)"])) {//字符串对象为空
}else{//不为空
}
4.图片的上传
图片上传格式比较固定
NSError *error = nil;
NSURLResponse *response = [NSURLResponse new];
NSString *imageStr = @"http://172.16.101.125:8080/wisdombus-controller/mobile/auth/uploadIMG.do";
NSURL *url = [NSURL URLWithString:imageStr];
NSMutableURLRequest *request = [NSMutableURLRequest requestWithURL:url];
// 设置请求方法
[request setHTTPMethod:@"POST"];
// 设置请求体
[request setHTTPBody:_imageData];
// 设置请求头的内容的类型
[request setValue:[NSString stringWithFormat:@"cesi%.0f.png",[[NSDate date] timeIntervalSince1970]] forHTTPHeaderField:@"fileName"];//图片文件名字
[request setValue:[NSString stringWithFormat:@"%lu",(unsigned long)_imageData.length] forHTTPHeaderField:@"fileSize"];//大小
[request setValue:[NSString stringWithFormat:@"%@"[[NSUserDefaults standardUserDefaults] objectForKey:@"uuid"]] forHTTPHeaderField:@"userId"];//
[request setValue:[NSString stringWithFormat:@"%d",2] forHTTPHeaderField:@"type"];
NSString *contentType = [NSString stringWithFormat:@"Content-Type multipart/form-data; boundary=%@", kBoundary];
[request setValue:contentType forHTTPHeaderField:@"Content-Type"];
// 发送异步请求
NSData *responseData = [NSURLConnection sendSynchronousRequest:request returningResponse:&response error:&error];
if (!error && responseData) {
NSDictionary *dic = [NSJSONSerialization JSONObjectWithData:responseData options:NSJSONReadingMutableLeaves error:&error];
if ([[dic objectForKey:@"result"] isEqualToString:@"true"]) {
//上传成功
}else {
//上传错误
}
}else if (error) {
//操作失败
}
5.图片的下载问题
图片加载影响主线程，所以要放到子线程中这里用GCD加载
dispatch_queue_t queue = dispatch_get_global_queue(DISPATCH_QUEUE_PRIORITY_DEFAULT, 0);
dispatch_async(queue, ^{
NSString * urlStr = @"http://img.taopic.com/uploads/allimg/140326/235113-1403260I05466.jpg";
UIImage * userImag = [UIImage imageWithData:[NSData dataWithContentsOfURL:[NSURL URLWithString:urlStr]]];
if (userImag != nil) {//请求成功
dispatch_async(dispatch_get_main_queue(), ^{//返回主线程
self.imageView.image = userImag;
});
}else{//请求失败，或请求不到图片
}
});
