我有这样的字符串
\"access_token=103782364732640461|2.ZmElnDTiZlkgXbT8e34Jrw__.3600.1281891600-10000186237005083013|yD4raWxWkDe3DLPJZIRox4H6Q_k.&expires=1281891600&secret=YF5OL_fUXItLJ3dKQpQf5w__&session_key=2.ZmElnDTiZlkgXbT8e34Jrw__.3600.1281891600-10000186237005083013&sig=a2b3fdac30d53a7cca34de924dff8440&uid=10000186237005083013\"
我想提取UID.