How to use Dart's Uri to parse links containing # - flutter

Question

I want to use dart's uri to parse the following url, the value in the parameter contains a ”#“
String url = 'scheme://a.b.c/d?p={"url": "https://test.test.com/#/a/b"}';
Uri uri = Uri.parse(url);
var map = uri.queryParameters;
print(map);
I want to get the value of parameter p through uri analysis
The result of the above code is as follows:
{p: {"url": "https://test.test.com/}
The desired result is as follows:
{p: {"url": "https://test.test.com/#/a/b}
Thanks!!!

Answer 1

You can try this. First, you replace # with a unique value. After parsing then again replace the hashtag.
String url = 'scheme://a.b.c/d?p={"url": "https://test.test.com/#/a/b"}';
Uri uri = Uri.parse(url.replaceAll("#","hashtag"));
var map = uri.queryParameters;
print(map.toString().replaceAll("hashtag","#"));
output: {p: {"url": "https://test.test.com/#/a/b"}}

Answer 2

The hash # must be replaced with its encoded value %23:
String url = 'scheme://a.b.c/d?p={"url": "https://test.test.com/%23/a/b"}';

Answer 3

The URL you supplied should have had characters with special meanings escaped/encoded in the first place. Uri.parse probably is parsing it correctly; you just gave it malformed input for what you intended.
What you should do instead is to encode the argument for your query string first:
String queryArgument = '{"url": "https://test.test.com/#/a/b"}';
String encodedArgument = Uri.encodeQueryComponent(queryArgument);
String url = 'scheme://a.b.c/d?p=$encodedArgument';
Uri uri = Uri.parse(url);
var map = uri.queryParameters;
print(map); // Prints: {p: {"url": "https://test.test.com/#/a/b"}}