发布HTTP请求

Question

我试图以这种方式向dropbox发布HTTP请求：

//NSString *urlString = [NSString stringWithFormat:@"https://api.dropbox.com/1/oauth/request_token"];
NSString *urlString = [NSString stringWithFormat:@"https://api.dropbox.com/1/delta"];
NSMutableURLRequest *request = [[NSMutableURLRequest alloc] init];
[request setURL:[NSURL URLWithString:urlString]];
[request setHTTPMethod:@"POST"];

//set headers

[request addValue:@"OAuth oauth_version=\"1.0\"" forHTTPHeaderField: @"Authorization"];

//create the body
NSMutableData *postBody = [NSMutableData data];


//post
[request setHTTPBody:postBody];

//get response
NSHTTPURLResponse* urlResponse = nil;  
NSError *error = [[NSError alloc] init];  
NSData *responseData = [NSURLConnection sendSynchronousRequest:request returningResponse:&urlResponse error:&error];  
NSString *result = [[NSString alloc] initWithData:responseData encoding:NSUTF8StringEncoding];
NSLog(@"Response Code: %d", [urlResponse statusCode]);
if ([urlResponse statusCode] >= 200 && [urlResponse statusCode] < 300) {
    NSLog(@"Response: %@", result);

    //here you get the response

}

响应应该是JSON字符串。

参数在这里：https://www.dropbox.com/developers/core/api#delta

它提供参数和版本，但我不知道如何设置它们。