为什么 asp.net core 应用程序不能在端口 4200 上运行？

Question

我尝试从端口 4200 在 aspnet 核心应用程序中运行 launchsettings.json 文件，但是该站点会连续无声地失败，但是如果我使用不同的端口（如 5000），它将工作。这是为什么？其他一切都一样，我可以在端口 4200 或 8000 上运行它吗？这个端口是免费的，没有被使用

网站不显示的示例代码

"iisSettings": {
    "windowsAuthentication": false,
    "anonymousAuthentication": true,
    "iisExpress": {
      "applicationUrl": "https://localhost:4200/",
      "sslPort": 4200
    }
  },
  "profiles": {
    "IIS Express": {
      "commandName": "IISExpress",
      "launchBrowser": true,
      "environmentVariables": {
        "ASPNETCORE_ENVIRONMENT": "Development"
      }
    },
    "Identity": {
      "commandName": "Project",
      "launchBrowser": true,
      "environmentVariables": {
        "ASPNETCORE_ENVIRONMENT": "Development"
      },
      "applicationUrl": "https://localhost:5001;http://localhost:5000"
    }
  }
}

网站显示的代码

"iisSettings": {
    "windowsAuthentication": false,
    "anonymousAuthentication": true,
    "iisExpress": {
      "applicationUrl": "https://localhost:5200/",
      "sslPort": 5200
    }
  },
  "profiles": {
    "IIS Express": {
      "commandName": "IISExpress",
      "launchBrowser": true,
      "environmentVariables": {
        "ASPNETCORE_ENVIRONMENT": "Development"
      }
    },
    "Identity": {
      "commandName": "Project",
      "launchBrowser": true,
      "environmentVariables": {
        "ASPNETCORE_ENVIRONMENT": "Development"
      },
      "applicationUrl": "https://localhost:5001;http://localhost:5000"
    }
  }
}