将图像转换为base64并以JSON格式上传到服务器 [英] converting image to base64 and uploading in JSON format to server

问题描述

我有问题。我需要将base64字符串转换为JSON字符串并将其传递给服务器。
例如我有一个base64字符串 / 9J / 4AAQSkZJRgABAQAAAQABAAD / 4QBYRXhpZgAATU0AKgAAAAgAAgESAAMAAAABAAEAAIdpAAQAAAABAAAAJgAAAAAAA6ABAAMAAAABAAEAAKACAAQAAAABAAAACqADAAQAAAABAAAACgAAAAD / 2wBDAAEBAQEBAQEBAQEBAQEBAQEBAQEBAQEBAQEBAQEBAQEBAQEBAQEBAQEBAQEBAQEBAQEBAQEBAQEBAQEBAQEBAQH / Z

I have a problem. I need to convert base64 string to JSON string and pass it to server. for example I have a base64 string /9j/4AAQSkZJRgABAQAAAQABAAD/4QBYRXhpZgAATU0AKgAAAAgAAgESAAMAAAABAAEAAIdpAAQAAAABAAAAJgAAAAAAA6ABAAMAAAABAAEAAKACAAQAAAABAAAACqADAAQAAAABAAAACgAAAAD/2wBDAAEBAQEBAQEBAQEBAQEBAQEBAQEBAQEBAQEBAQEBAQEBAQEBAQEBAQEBAQEBAQEBAQEBAQEBAQEBAQEBAQEBAQH/Z

我需要将其转换为JSON格式。我执行以下操作：

i need to convert it to JSON format. I do the following:

+(NSData *)prepareForUploading:(NSString *)base64Str
{
    NSDictionary *dict=[NSDictionary dictionaryWithObjects:[NSArray arrayWithObjects:base64str, nil] forKeys:[NSArray arrayWithObjects:@"picture", nil]];

    NSData *preparedData=[NSJSONSerialization dataWithJSONObject:dict options:NSJSONWritingPrettyPrinted error:nil];    
    return preparedData;
};

这里我如何制作 NSURLRequest

-(NSString *)uploadPict:(NSString *)pict
{
    NSLog(@"Server: upload: called");
    NSData *prepPictData=[[self class] prepareForUploading:pict];
    NSString *preparedBase64StrInJSON=[[NSString alloc] initWithData:prepPictData encoding:NSUTF8StringEncoding];

    //here I'm adding access token to request
    NSString *post = [NSString stringWithFormat:@"accessToken=%@&object=%@", self.key, preparedBase64StrInJSON];
    NSData *postData = [post dataUsingEncoding:NSUTF8StringEncoding allowLossyConversion:YES];
    NSString *postLength = [NSString stringWithFormat:@"%d", [postData length]];

    NSMutableURLRequest *request = [[NSMutableURLRequest alloc] init];
    [request setURL:[NSURL URLWithString:[NSString stringWithFormat:@"[e-mail]", serverAPIPath]]];
    [request setHTTPMethod:@"POST"];
    [request setValue:@"postLength" forHTTPHeaderField:@"Content-Length"];
    [request setValue:@"application/x-www-form-urlencoded" forHTTPHeaderField:@"Content-Type"];
    [request setHTTPBody:postData];    

    NSURLResponse *response;
    NSError *error;
    NSData *urlData=[NSURLConnection sendSynchronousRequest:request returningResponse:&response error:&error];
    //....
}

但我得到无效长度对于来自服务器的Base-64字符数组。怎么了？
如果我将我的令牌和JSON粘贴到 http://hurl.it/ 并使用它发出请求 - 一切正常。

But I get "Invalid length for a Base-64 char array" from server. What's wrong? If I paste my token and JSON to http://hurl.it/ and make request using it - everything goes normally.

我认为问题是 / base64字符串中的符号以及JSON中的结果/符号。
也许它是 [postData length] ：如果我从JSON字符串中删除 \ / 字符：
9j4AAQSkZJRgABAQAAAQABAAD4QBYRXhpZgAATU0AKgAAAAgAAgESAAMAAAABAAEAAIdpAAQAAAABAAAAJgAAAAAAA6ABAAMAAAABAAEAAKACAAQAAAABAAAACqADAAQAAAABAAAACgAAAAD2wBDAAEBAQEBAQEBAQEBAQEBAQEBAQEBAQEBAQEBAQEBAQEBAQEBAQEBAQEBAQEBAQEBAQEBAQEBAQEBAQEBAQEBAQHZ 请求将正常地执行，但此64位编码串是不一样的

I think the problem is / symbols in base64 string and as a result / symbols in JSON. Maybe it is something with [postData length]: if I erase \/ characters from JSON string: 9j4AAQSkZJRgABAQAAAQABAAD4QBYRXhpZgAATU0AKgAAAAgAAgESAAMAAAABAAEAAIdpAAQAAAABAAAAJgAAAAAAA6ABAAMAAAABAAEAAKACAAQAAAABAAAACqADAAQAAAABAAAACgAAAAD2wBDAAEBAQEBAQEBAQEBAQEBAQEBAQEBAQEBAQEBAQEBAQEBAQEBAQEBAQEBAQEBAQEBAQEBAQEBAQEBAQEBAQEBAQHZ request will perform normally but this base64 encoded string is not the same.

请，帮助我解决这个问题

Please, help me to solve this problem

推荐答案

jString是你的base64字符串，首先使用以下行

jString is your base64 string, first use following line

[self encodeString：jString] ;

然后调用以下。

NSString *URL = [NSString stringWithFormat:@"forms.asmx/CreateUpdate?"];

URL=[NSString stringWithFormat:@"%@%@", USERS_API_ROOT_URL, URL];
NSString *post = [NSString stringWithFormat:@"apiKey=A0B1I2L3A4L5-A1D3-4F30-5AB2-C8DEE266&strPost=%@",jString];

unsigned long long postLength = [post length];
NSString *contentLength = [NSString stringWithFormat:@"%llu",postLength];

NSData *postData = [post dataUsingEncoding:NSUTF8StringEncoding allowLossyConversion:YES];

NSMutableURLRequest *request = [[NSMutableURLRequest alloc] init] ;
[request setURL:[NSURL URLWithString:URL]];
[request setHTTPMethod:@"POST"];
[request setValue:contentLength forHTTPHeaderField:@"Content-Length"];
[request setValue:@"application/x-www-form-urlencoded" forHTTPHeaderField:@"Content-Type"];
[request setHTTPBody:postData ];

(void)[[NSURLConnection alloc] initWithRequest:request  delegate:self];


-(NSString *)encodeString:(NSString *)string
{
    NSString *newString = (__bridge_transfer NSString*)CFURLCreateStringByAddingPercentEscapes(kCFAllocatorDefault, (CFStringRef)string, NULL,CFSTR(":/?#[]@!$ &'()*+,;=\"<>%{}|\\^~`"), CFStringConvertNSStringEncodingToEncoding(NSUTF8StringEncoding));
    return newString;
}

希望它能够正常工作。

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