RTM, RC2 & RC1 Answer

You need to use launchSettings.json in the properties folder of the project. Note the sslPort setting. Note that for RC1 ASPNETCORE_ENVIRONMENT becomes Hosting:Environment.

{
  "iisSettings": {
    "windowsAuthentication": false,
    "anonymousAuthentication": true,
    "iisExpress": {
      "applicationUrl": "http://localhost:1025/",
      "sslPort": 44300
    }
  },
  "profiles": {
    "IIS Express": {
      "commandName": "IISExpress",
      "launchBrowser": true,
      "environmentVariables": {
        "ASPNETCORE_ENVIRONMENT": "Development"
      }
    },
    "web": {
      "commandName": "web",
      "environmentVariables": {
        "ASPNETCORE_ENVIRONMENT": "Development"
      }
    }
  }
}

Beta 8 Answer

您可以编辑.xproj文件并添加SSLPort要手动添加的元素，但这实际上应适用于任何版本的VS，我建议您在ASP.NET Tooling GitHub页面上提出问题：

<PropertyGroup>
    <SchemaVersion>2.0</SchemaVersion>
    <DevelopmentServerPort>1025</DevelopmentServerPort>
    <SSLPort>44300</SSLPort>
</PropertyGroup>

端口号必须是44300和44399之间的数字。