感谢科林，最终答案是:

bool isIOS = Theme.of(context).platform == TargetPlatform.iOS;

import 'dart:io' as io;

if(io.Platform.isAndroid){
 doSomething();
}else {
 doSomethingElse();
}

你可以这样做

defaultTargetPlatform == TargetPlatform.iOS
          ? kIOSTheme
          : kDefaultTheme,

从导入'包:flutter/foundation.dart';

为更简单的方式为网络和应用程序。试试这个

import 'dart:io' show Platform;
import 'package:flutter/foundation.dart' show kIsWeb;


var platformName = '';
if (kIsWeb) {
  platformName = "Web";
} else {
  if (Platform.isAndroid) {
    platformName = "Android";
  } else if (Platform.isIOS) {
    platformName = "IOS";
  } else if (Platform.isFuchsia) {
    platformName = "Fuchsia";
  } else if (Platform.isLinux) {
    platformName = "Linux";
  } else if (Platform.isMacOS) {
    platformName = "MacOS";
  } else if (Platform.isWindows) {
    platformName = "Windows";
  }
}
print("platformName :- "+platformName.toString());

import 'dart:io' show Platform;  //at the top

String os = Platform.operatingSystem; //in your code
print(os);

您可以将此扩展添加到项目中

import 'package:flutter/material.dart';

extension PlatformExtension on BuildContext {
  bool get isMobile =>
      Theme.of(this).platform == TargetPlatform.iOS ||
      Theme.of(this).platform == TargetPlatform.android;

  bool get isDesktop =>
      Theme.of(this).platform == TargetPlatform.macOS ||
      Theme.of(this).platform == TargetPlatform.windows ||
      Theme.of(this).platform == TargetPlatform.linux;
}

extension TargetPlatformExtension on TargetPlatform {
  bool get isMobile =>
      this == TargetPlatform.iOS || this == TargetPlatform.android;

  bool get isDesktop =>
      this == TargetPlatform.linux ||
      this == TargetPlatform.macOS ||
      this == TargetPlatform.windows;
}

现在您可以使用。

内置context => context.isDesktop 目标平台=> defaulttarded平台

建议从上下文访问平台。

要检测您的应用程序是否在浏览器上运行，您可以轻松地使用基础库中的kIsWeb常量。

import 'package:flutter/foundation.dart';

  log('$kIsWeb'); // will print true if the app is running on a browser

注意，如果你在桌面上运行web应用程序，isDesktop getter将返回true，对于移动平台也是如此。 为了避免这种情况。

import 'package:flutter/foundation.dart';

  if (!kIsWeb && defaultTargetPlatform.isDesktop) {
    // do stuff for desktop apps only
  }

  if (!kIsWeb && defaultTargetPlatform.isMobile) {
    // do stuff for mobile apps only
  }

您可以修改扩展以获得您喜欢的实现。