摘抄自：https://blog.csdn.net/huaxin_sky/article/details/79529758
已经测试过了。
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<a class="ceshi" href="tencent://message/?uin=***这是QQ号*****&Menu=yes& Service=300&sigT=42a1e5347953b64c5ff3980f8a6e644d4b31456cb0b6ac6b27663a3c4dd0f4aa14a543b1716f9d45">打开QQ</a>
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