问题
I have the following QString that I want to extract only the access_token value which is "http%3a%2f%2fschemas.xmlsoap....." How to do that?
{"token_type":"http://schemas.xmlsoap.org/ws/2009/11/swt-token-profile-1.0","access_token":"http%3a%2f%2fschemas.xmlsoap.org%2fws%2f2005%2f05%2fidentity%2fclaims%2fnameidentifier=asdasr21321214a%2f%2fschemas.microsoft.com%2faccwresscontrolservice%2f2010%2f07%2fclaims%2fidentityprovider=https%3a%2f%2fdatamarket.accesscontrol.windows.net%2f&Audience=http%3a%2f%2fapi.microsofttranslator.com&ExpiresOn=1347332993&Issuer=https%3a%2f%2fdatamarket.accesscontrol.windows.net%2f&HMACSHA256=sFqvp2a2xXc3VBdxYZ6xHQf%2fKkOydnuX6VK7A6Yf55k%3d","expires_in":"599","scope":"http://api.microsofttranslator.com"}
回答1:
Quick and dirty, only for demonstration of QString::section:
QString Data("{...you json data...}");
QString AccessToken = data.section("access_token\":\"",1).section("\"",0,0);
Consider: QString::section is slow and heavy, creating QStringList and converting tokens to RegExp in background. But I still do use it frequently in some cases.
回答2:
Check out QJson at http://qjson.sourceforge.net/.
You can easily parse a string into tokenized attributes. From the usage page:
QJson::Parser parser;
QString json = "{your json above}";
bool ok;
QVariant result = parser.parse (json, &ok);
qDebug() << result["access_token"].toString();
Have fun.
回答3:
Try this regex:
\"access_token\":\"([^\"]*)\"
explain:
( subexpression )Captures the matched subexpression and assigns it a zero-based ordinal number.
[^ character_group ]Negation: Matches any single character that is not in character_group. By default, characters in character_group are case-sensitive.
来源：https://stackoverflow.com/questions/12362151/extract-specific-string