TriggerEventHandler在单元测试角度4

本文介绍了TriggerEventHandler在单元测试角度4的处理方法，对大家解决问题具有一定的参考价值，需要的朋友们下面随着小编来一起学习吧！ 问题描述 29岁程序员，3月因学历无情被辞！ 我有一个元素<button class="next-btn" (mouseup)="someMethod()">Next</button>我想在测试中模拟mouseup事件并且我这样做I want to simulate mouseup event in testing and i do thisconst nextBtnElem = fixture.debugElement.nativeElement;const elem = nextBtnElem.getElementsByTagName('button')[1]elem.triggerEventHandler('mouseup', null);它不起作用，但如果我这样更改it doesn't work, but if i change it like thisconst nextBtnElem = fixture.debugElement.query(By.css('.next-btn');nextBtnElem.triggerEventHandler('mouseup', null);现在它正在工作。我无法理解为什么第一个选项不起作用？Now its working. I can't understand why first optional doesn't work?推荐答案 triggerEventHandler 是一个存在于Angular的上的函数DebugElement 。在你的第一个代码片段中，你在DOM对象上调用 triggerEventHandler ，它不提供这个功能。在DOM对象上，你可以使用 dispatchEvent 但您必须致电 fixture.detectChanges（）; 在触发事件和断言之间。triggerEventHandler is a function that exists on Angular's DebugElement. In your first code snippet you are calling triggerEventHandler on a DOM object, that does not provide this functionality. On DOM objects you could use dispatchEvent but you must call fixture.detectChanges(); between triggering your event and your assertions then. 这篇关于TriggerEventHandler在单元测试角度4的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持！ 上岸，阿里云！