Platform.environment在运行驱动程序测试之前，我尝试使用Dart
读取环境变量，它似乎工作正常。下面是一个简单的示例，该示例使用
FLUTTER_DRIVER_RESULTSenv变量设置测试摘要的输出目录。
import 'dart:async';import 'dart:io' show Platform;import 'package:flutter_driver/flutter_driver.dart';import 'package:test/test.dart';void main() { // Load environmental variables String resultsDirectory = Platform.environment['FLUTTER_DRIVER_RESULTS'] ?? '/tmp'; print('Results directory is $resultsDirectory'); group('increment button test', () { FlutterDriver driver; setUpAll(() async { // Connect to the app driver = await FlutterDriver.connect(); }); tearDownAll(() async { if (driver != null) { // Disconnect from the app driver.close(); } }); test('measure', () async { // Record the performance timeline of things that happen Timeline timeline = await driver.traceAction(() async { // Find the scrollable user list SerializableFinder incrementButton = find.byValueKey( 'increment_button'); // Click the button 10 times for (int i = 0; i < 10; i++) { await driver.tap(incrementButton); // Emulate time for a user's finger between taps await new Future<Null>.delayed(new Duration(milliseconds: 250)); } }); TimelineSummary summary = new TimelineSummary.summarize(timeline); summary.writeSummaryToFile('increment_perf', destinationDirectory: resultsDirectory, pretty: true); summary.writeTimelineToFile('increment_perf', destinationDirectory: resultsDirectory, pretty: true); }); });}
