前台异步传过来的URL中获取token/获取string链接中的token

1、链接例子：

string url = "https://domainName:port/1/2/3/4.htm?sysCode=1001020&token=QXJzemR3YXlWdm9YMFhneFU0c2tqSXp6YmJqMVNQSUVlWndEbm9yellBNHp5SXBmK2gxVGxGT1NBdVhkd3dTWTFQdG1xajBPV1FmRWVSRStBRTVMSFpCdkZRdEFaQ25KVCtxOWRITTk5bEczYW1KL0N0cUtEamdheHBaU3ZFRGRacDh5NGc1TEF0cDkrUGQrUGEwazhoc0Qzc1BaUFdkRXM1aEQ3SzVyNmEzcDdhVUZlWVU5SlNwdmdNQ0N3anJUaTR6SS9USEltWXZuSGEwVVZPNFVhdzUyZFRPWC8zbk42VWpWZDNZdTU5bERqcHBYalpvY0ZXMHJnS08zWFZadEZUUEdKdDIrVTNWTklHb1psZE9Gc0cwVElzTVZNL3NkR1NiSGVuS3B2aXlFMEx3cngxOXJuZTVSSEVNY0VyNGJGNDlYNDhnSXVJc2NVRUZMbzA2ZVdpWWFGT21SV1BhOGpqbURDcHdQN1JjPQ==";string url = "https://domainName:port