flutter:url_launcher打开浏览器时报错 PlatformException(channel-error, Unable to establish connection on channel:

一，报错信息:

E/flutter (20255): [ERROR:flutter/runtime/dart_vm_initializer.cc(40)] Unhandled Exception: PlatformException(channel-error, Unable to establish connection on channel: "dev.flutter.pigeon.url_launcher_android.UrlLauncherApi.openUrlInApp"., null, null)
E/flutter (20255): #0      UrlLauncherApi.openUrlInApp (package:url_launcher_android/src/messages.g.dart:198:7)
E/flutter (20255): <asynchronous suspension>
E/flutter (20255): #1      UrlLauncherAndroid.launchUrl (package:url_launcher_android/url_launcher_android.dart:100:19)
E/flutter (20255): <asynchronous suspension>
E/flutter (20255): #2      _CallPhonePageState._launchUrl (package:demo3/pages/CallPhonePage.dart:18:10)
E/flutter (20255): <asynchronous suspension>
E/flutter (20255): 

二，解决:

原代码:

  //打开游览器
  Future<void> _launchUrl(String url) async {
    final Uri _url = Uri.parse(url);
    if (!await launchUrl(_url)) {
      throw Exception('Could not launch $_url');
    }
  }

android需要增加权限:

编辑android/app/src/main/AndoridManifest.xml

在queries一项中增加:

<!-- If your app checks for SMS support -->
  <intent>
    <action android:name="android.intent.action.VIEW" />
    <data android:scheme="sms" />
  </intent>
  <!-- If your app checks for call support -->
  <intent>
    <action android:name="android.intent.action.VIEW" />
    <data android:scheme="tel" />
  </intent>
  <!-- If your application checks for inAppBrowserView launch mode support -->
  <intent>
    <action android:name="android.support.customtabs.action.CustomTabsService" />
  </intent>

 说明：增加support后，关闭运行的app,重新运行即可生效