POST請求之表單上傳圖片

表單上傳:

表單上傳一般是用于上傳大型文件給服務器，比如圖片、視頻、音頻等，由于服務器在接收內容的時候需要組合成類似于表格的形式，因此在上傳大型文件給服務器的時候就需要用到表單上傳的方式上傳內容，而在上傳大型文件的時候采用POST形式長傳

相關說明:

在客戶端拼接表單格式的時候，首先應聲明表單的分割線，然后才能上傳，聲明分割符在“請求頭”中添加，格式如下：

下面示例中name所對應的是key值
lng對應的值是key值
分隔符號是--OCqxMF6-JxtxoMDHmoG5W5eY9MGRsTBp

拼接后的格式類似于

示例:

通過表單上傳格式上傳數據給服務器，格式如下：http://m.goufang.com/api/ershou/eshonglist
--0xKhTmLbOuNdArY
Content-Disposition: form-data; name="cityid"

dl
--0xKhTmLbOuNdArY
Content-Disposition: form-data; name="page"

1
--0xKhTmLbOuNdArY--

示例代碼:

#import <Foundation/Foundation.h>
#import <UIKit/UIKit.h>
@protocol ConnectModelDelegate <NSObject>

- (void)connectFinished:(NSData *)data;

@end

@interface ConnectModel : NSObject<NSURLConnectionDataDelegate>
{
    int classIsa;
}
@property (nonatomic, assign) id<ConnectModelDelegate>delegate;

@property (nonatomic, retain) NSMutableData *receiveData;
- (void)startConnection:(NSString *)str parmaters:(NSDictionary *)parmaters;

+ (ConnectModel *)connectWithUrl:(NSString *)url delegate:(id<ConnectModelDelegate>)delegate parmaters:(NSDictionary *)parmaters;
@property (nonatomic, copy) NSString *requestUrl;

@end

#import "ConnectModel.h"
#import <objc/runtime.h>
#import <Foundation/NSObjCRuntime.h>

@implementation ConnectModel

+ (ConnectModel *)connectWithUrl:(NSString *)url delegate:(id<ConnectModelDelegate>)delegate parmaters:(NSDictionary *)parmaters
{
        ConnectModel *model = [[ConnectModel alloc] init];
        model.delegate = delegate;
        [model startConnection:url parmaters:parmaters];
        return model;
    
}

- (void)startConnection:(NSString *)str parmaters:(NSDictionary *)parmaters
{
    NSString *delegateDescription = [[self.delegate class] description];
    classIsa = (int)objc_getClass([delegateDescription UTF8String]);
    
    // 異步網絡連接
    NSString *string = [str stringByAppendingString:[parmaters objectForKey:@"cityid"]];
    self.requestUrl = str;
    
    NSString *bodyStr = @"--0xKhTmLbOuNdArY";
    
    bodyStr = [bodyStr stringByAppendingString:@"\r\n"];
    
    bodyStr = [bodyStr stringByAppendingString:@"Content-Disposition: form-data; name=\"cityid\"\r\n\r\n"];
    bodyStr = [bodyStr stringByAppendingString:[parmaters objectForKey:@"cityid"]];
    bodyStr = [bodyStr stringByAppendingString:@"\r\n"];
    bodyStr = [bodyStr stringByAppendingString:@"--0xKhTmLbOuNdArY\r\n"];
    bodyStr = [bodyStr stringByAppendingString:@"Content-Disposition: form-data; name=\"page\"\r\n\r\n"];
    bodyStr = [bodyStr stringByAppendingString:[parmaters objectForKey:@"page"]];
    bodyStr = [bodyStr stringByAppendingString:@"\r\n"];
    bodyStr = [bodyStr stringByAppendingString:@"--0xKhTmLbOuNdArY--"];
    
    
     NSLog(@"%@", str);
    
    
    str = [str stringByAddingPercentEscapesUsingEncoding:NSUTF8StringEncoding];
    
    NSURL *url = [NSURL URLWithString:str];
    
    NSMutableURLRequest *request = [NSMutableURLRequest requestWithURL:url];
    
    [request setHTTPMethod:@"POST"];
    [request setValue:@"multipart/form-data; charset=utf-8; boundary=0xKhTmLbOuNdArY" forHTTPHeaderField:@"Content-Type"];
    
    NSData *data = [bodyStr dataUsingEncoding:NSUTF8StringEncoding];
    
    
    
    [request setHTTPBody:data];
    [NSURLConnection connectionWithRequest:request delegate:self];
    
    //    POST http://m.goufang.com/api/loupan/hometuijian HTTP/1.1
    //Host: m.goufang.com
    //    Proxy-Connection: keep-alive
    //    Content-Type: multipart/form-data; charset=utf-8; boundary=0xKhTmLbOuNdArY
    //    Content-Length: 162
    //Connection: keep-alive
    //Cookie: ASP.NET_SessionId=khkjhvak2mobhfi34pgdaqc5
    //    User-Agent: Paros/3.2.13
}

- (void)connection:(NSURLConnection *)connection didReceiveResponse:(NSURLResponse *)response
{
    self.receiveData = [NSMutableData data];
}
- (void)connection:(NSURLConnection *)connection didReceiveData:(NSData *)data
{
    [_receiveData appendData:data];
}
- (void)connectionDidFinishLoading:(NSURLConnection *)connection
{
    NSStringEncoding enc = CFStringConvertEncodingToNSStringEncoding (kCFStringEncodingGB_18030_2000);
    NSString *value = [[NSString alloc] initWithData:_receiveData encoding:enc];
    
    NSData *data = [value dataUsingEncoding:NSUTF8StringEncoding];
    NSLog(@"value = %@", value);
    [self.delegate connectFinished:data];
}
- (void)connection:(NSURLConnection *)connection didFailWithError:(NSError *)error
{
    NSLog(@"error = %@", error);
}

#import <UIKit/UIKit.h>

@interface ViewController : UIViewController


@end

#import "ViewController.h"
#import "ConnectModel.h"
@interface ViewController ()

@end

@implementation ViewController
- (IBAction)request:(id)sender {
    
     [ConnectModel connectWithUrl:@"http://m.goufang.com/api/ershou/eshonglist" delegate:nil parmaters:@{@"cityid":@"dl", @"page":@"1"}];
    
}

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

- (void)didReceiveMemoryWarning {
    [super didReceiveMemoryWarning];
}
@end

注意:

表單上傳必須嚴格按照http的規定格式去拼接url!!