IOS cannot decode emoji unicode in json format correctly, and Emoji icons are displayed as squares

问题

I am working on an iPhone app which allows people to send messages with Emoji icons. I saved the icon in Mysql with charset utf8mb4 and collation utf8mb4_unicode_ci, and all the emoji icons is saved correctly in my database. However, when I return json back to the client (php json_encode), the Emoji is encoded as something like this: '\ud83d\ude04', and iPhone displays it as a square. However, if I return as XML, the Emoji Icon won't become unicode like this: '\ud83d\ude04', it will just be the icon.

I am wondering if this is an issue on my server, or on my client. If it is my client, how can object c decode it correctly.

Can someone please help?

Thanks

回答1:

"\ud83d\ude04" is the JSON Unicode escape sequence for U+D83D U+DE04, which is the "surrogate pair" for the Unicode U+1F604 (SMILING FACE WITH OPEN MOUTH AND SMILING EYES).

But NSJSONSerialization decodes this correctly, as can be seen in the following example:

const char *jsonString = "{ \"emoji\": \"\\ud83d\\ude04\" }";
NSLog(@"JSON: %s", jsonString);
NSData *jsonData = [NSData dataWithBytes:jsonString length:strlen(jsonString)];
NSError *error;
NSDictionary *jsonDict = [NSJSONSerialization JSONObjectWithData:jsonData options:0 error:&error];
self.myLabel.text = [jsonDict objectForKey:@"emoji"];
NSLog(@"Emoji: %@", self.myLabel.text);

Output:

JSON: { "emoji": "\ud83d\ude04" }
Emoji: 😄

and the Emoji symbol is also displayed correctly (tested with iPhone device and Simulator).

回答2:

Please follow following steps:

Convert Emoji characters to base64 and send to server using Json.
On server side save base64 in database without decode.
When you want to display Emoji on Application then retrieve same base64 data from server.
Decode retrieve string and display on app.
Your Emoji character will display properly.

Note: When you want to Show on webPage then Decode data when you display data on WebPage.

回答3:

Our team fixed this problem by transfer utf data to server, saving them in mysql utf8mb4 codepage and receiving with base64. Server convert saved data to base64 on demand.

来源：https://stackoverflow.com/questions/14488503/ios-cannot-decode-emoji-unicode-in-json-format-correctly-and-emoji-icons-are-di

标签

ios

encode

json

emoji

utf8mb4