Apple环境中POST提交数据并获取返回值（XML格式的字符串）

以下实例通过POST方法提交数据并返回结果

@try {  
    NSError *error;  
    NSURL *url = [NSURL URLWithString:@http://www.corp.com/info.aspx];  
    
    NSMutableDictionary *dic =" [[NSMutableDictionary" alloc] init];  
     
    [dic setValue:@"14" forKey:@"type"];  
    [dic setValue:@"POST" forKey:@"method"];  
    [dic setValue:@"1" forKey:@"siteid"];  
         
    NSString *myBounds = [[NSString alloc] initWithString:@"test"];  
    NSMutableURLRequest *myRequest = [NSMutableURLRequest requestWithURL:url];  
    NSString *myContent = [NSString stringWithFormat:@"multipart/form-data; boundary=%@",myBounds];  
    [myRequest setValue:myContent forHTTPHeaderField:@"content-type"];  
    [myRequest setHTTPMethod:@"POST"];  
    [myRequest setHTTPBody:[self createFormData:dic withBoundary:myBounds]];  
       
    NSURLResponse *response;  
    NSData *myReturn = [NSURLConnection sendSynchronousRequest:myRequest returningResponse:&response error:&error];  
    
    NSString *str = [[NSString alloc] initWithData:myReturn encoding:NSUTF8StringEncoding];  
}  
@catch (NSException *exception) {  
    //  
}  
@finally {  
    //  
}  

以上方法中用到的createFormData方法：

- (NSData*)createFormData:(NSDictionary *)myDictionary withBoundary:(NSString *)myBounds{  
    NSMutableData *myReturn = [[NSMutableData alloc] initWithCapacity:10];  
    NSArray *formKeys = [myDictionary allKeys];  
    
    for(int i=0;i<[formKeys count];i++){  
        [myReturn appendData:[[NSString stringWithFormat:@"--%@\n",myBounds] dataUsingEncoding:NSUTF8StringEncoding]];  
        [myReturn appendData:[[NSString stringWithFormat:@"content-disposition: form-data; name=\"%@\"\n\n%@\n", [formKeys objectAtIndex:i], [myDictionary valueForKey:[formKeys objectAtIndex:i]]] dataUsingEncoding:NSUTF8StringEncoding]];  
    }  
    
    [myReturn appendData:[[NSString stringWithFormat:@"--%@--\n", myBounds] dataUsingEncoding:NSUTF8StringEncoding]];  
    return myReturn;  
}