“Connection refused” Angular 4 localhost development

问题

I am getting "Connection refused" page while running Angular 4 app locally.

URL is http://localhost:4200/

Running the app with ng serve --open command.

UPDATE 1: angular.json

With some sources I have found that the angular cli file is now changed as angular.json.

bellow are the details from agnular.json

"$schema": "./node_modules/@angular/cli/lib/config/schema.json",
"version": 1,
"newProjectRoot": "projects",
"projects": {
  "angular-forms": {
    "root": "",
    "sourceRoot": "src",
    "projectType": "application",
    "architect": {
      "build": {
        "builder": "@angular-devkit/build-angular:browser",
        "options": {
          "outputPath": "dist",
          "index": "src/index.html",
          "main": "src/main.ts",
          "tsConfig": "src/tsconfig.app.json",
          "polyfills": "src/polyfills.ts",
          "assets": [
            "src/assets",
            "src/favicon.ico"
          ],
          "styles": [
            "src/styles.css"
          ],
          "scripts": []
        },
        "configurations": {
          "production": {
            "optimization": true,
            "outputHashing": "all",
            "sourceMap": false,
            "extractCss": true,
            "namedChunks": false,
            "aot": true,
            "extractLicenses": true,
            "vendorChunk": false,
            "buildOptimizer": true,
            "fileReplacements": [
              {
                "replace": "src/environments/environment.ts",
                "with": "src/environments/environment.prod.ts"
              }
          ]
        }
      }
    },
    "serve": {
      "builder": "@angular-devkit/build-angular:dev-server",
      "options": {
        "browserTarget": "angular-forms:build"
      },
      "configurations": {
        "production": {
          "browserTarget": "angular-forms:build:production"
        }
      }
    },
    "extract-i18n": {
      "builder": "@angular-devkit/build-angular:extract-i18n",
      "options": {
        "browserTarget": "angular-forms:build"
      }
    },
    "test": {
      "builder": "@angular-devkit/build-angular:karma",
      "options": {
        "main": "src/test.ts",
        "karmaConfig": "./karma.conf.js",
        "polyfills": "src/polyfills.ts",
        "tsConfig": "src/tsconfig.spec.json",
        "scripts": [],
        "styles": [
          "src/styles.css"
        ],
        "assets": [
          "src/assets",
          "src/favicon.ico"
        ]
      }
    },
    "lint": {
      "builder": "@angular-devkit/build-angular:tslint",
      "options": {
        "tsConfig": [
          "src/tsconfig.app.json",
          "src/tsconfig.spec.json"
        ],
        "exclude": [
          "**/node_modules/**"
        ]
      }
    }
  }
},
"angular-forms-e2e": {
  "root": "",
  "sourceRoot": "",
  "projectType": "application",
  "architect": {
    "e2e": {
      "builder": "@angular-devkit/build-angular:protractor",
      "options": {
        "protractorConfig": "./protractor.conf.js",
        "devServerTarget": "angular-forms:serve"
      }
    },
    "lint": {
      "builder": "@angular-devkit/build-angular:tslint",
      "options": {
        "tsConfig": [
          "e2e/tsconfig.e2e.json"
        ],
        "exclude": [
          "**/node_modules/**"
        ]
      }
    }
  }
}
},
"defaultProject": "angular-forms",
"schematics": {
"@schematics/angular:component": {
  "prefix": "app",
  "styleext": "css"
},
"@schematics/angular:directive": {
  "prefix": "app"
}
}
}

Please let me know if more details required

Screenshot is attached for more details.

回答1:

Go to command line and run ng serve --port 4200.

Hope this helps.

回答2:

Instead of localhost try accessing your app using your IP like this,

(Assuming that you're using Windows) In your command line, Type => ipconfig and copy the ip address it returns,

For, Eg if the IP address is, 192.168.0.10 then, you can access your application (after issuing ng server) as,

http://192.168.0.10:4200

Hope this helps!

回答3:

I have found a solution for this and it is quite simple. As @Devid ask mi about corporate proxy the I have started searching solution in this direction. Finally i have found that there was minor mistake in my LAN proxy settings.

While configuring proxy server I forget to enable the option "Bypass proxy server for local addresses" and which is causing mi above error.

Below is the screenshot for more details.

来源：https://stackoverflow.com/questions/51531931/connection-refused-angular-4-localhost-development