Angular 4,没有NgForm的提供者

Question

我有一些使用ReactiveForms的组件,但是当我尝试访问它们时,我得到"NgForm没有提供者".

奇怪的是,在运行"ng serve"时没有发生这种情况,而且只是在运行"ng serve --aot"时,甚至在使用"ng build --prod"进行部署时才会发生这种情况

任何人都知道这里发生了什么？

这是完全的回溯

core.es5.js:1020 ERROR错误:未捕获(在承诺中):错误:没有NgForm的提供者!错误:没有NgForm的提供者!at injectError(core.es5.js:1169)atNisProviderError(core.es5.js:1207)at ReflectiveInjector_.webpackJsonp .../../../core/@angular/core.es5.js.ReflectiveInjector_.throwOrNull(core.es5.js:2649)在ReflectiveInjector .webpackJsonp .../../../core/@angular/core.es5.js.ReflectiveInjector_.getByKeyDefault(core.es5.js:2688)在ReflectiveInjector .webpackJsonp .../../../core/@angular/core.es5.js.ReflectiveInjector_.getByKey(core.es5.js:2620)at RefinInjector .webpackJsonp .../../../core/@angular/core.es5.js.ReflectiveInjector_.get(core.es5.js:2489)at resolveNgModuleDep( core.es5.js:9489)在resolveDep的NgModuleRef_.webpackJsonp .../../../core/@angular/core.es5.js.NgModuleRef_.get(core.es5.js:10577)(核心. es5.js:11080)在injectPro(core.es5.js:1169)处的createProviderInstance(core.es5.js:10909)处于noProviderError(core.es5.js:1207)处于ReflectiveInjector .webpackJsonp .../../../core/@angular/core.es5.js.ReflectiveInjector_.throwOrNull(core.es5.js:2649)在ReflectiveInjector .webpackJsonp .../../../core/@angular/core.es5.js.ReflectiveInjector_.getByKeyDefault(core.es5.js:2688)在ReflectiveInjector .webpackJsonp .../../../core/@angular/core.es5.js.ReflectiveInjector_.getByKey(core.es5.js:2620)at RefinInjector .webpackJsonp .../../../core/@angular/core.es5.js.ReflectiveInjector_.get(core.es5.js:2489)at resolveNgModuleDep( core.es5.js:9489)在resolveDep的NgModuleRef_.webpackJsonp .../../../core/@angular/core.es5.js.NgModuleRef_.get(core.es5.js:10577)(核心. es5.js:11080)at-createProviderInstance(core.es5.js:10909)at resolvePromise(zone.js:795)at resolvePromise(zone.js:766)at zone.js:844 at ZoneDelegate.webpackJsonp ... /.在ZoneDelegate.webpackJsonp ... /的Object.onInvokeTask(core.es5.js:3881)中的./../../zone.js/dist/zone.js.ZoneDelegate.invokeTask(zone.js:425). Zone.webpackJsonp中的./../../zone.js/dist/zone.js.ZoneDelegate.invokeTask(zone.js:424).../../../../zone.js/dist /zone.js.Zun.runTask(zone.js:192)位于ZoneTask.webpackJsonp的drainMicroTaskQueue(zone.js:602).../../../../zone.js/dist/zone.js .ZoneTask.invokeTask [as invoke](zone.js:503)at invokeTask(zone.js:1427)

Answer 1

我会仔细检查您是否正在ReactiveFormsModule为使用反应式形式的组件导入正确的模块。我经常遇到在一个组件中导入的可观察运算符的相同类型的问题，但在使用该运算符的另一个组件中却没有导入。该应用程序将运行ng serve，但不是ng build/aot。