Question

我尝试创建http://angularjs.blogspot.no/2015/03/forms-in-angular-2.html中描述的简单表单，但是当我添加

时

import {forms, required} from 'angular2/forms';

与

发生冲突

TypeError: Cannot read property 'annotations' of undefined

TypeError: Cannot read property 'annotations' of undefined
    at ReflectionCapabilities.System.register.execute.$__export.annotations (http://localhost:9090/node_modules/angular/dist/js/prod/es6/angular2/src/reflection/reflection_capabilities.es6!eval:81:40)
    at Reflector.System.register.execute.$__export.annotations (http://localhost:9090/node_modules/angular/dist/js/prod/es6/angular2/src/reflection/reflector.es6!eval:81:50)
    at DirectiveMetadataReader.System.register.execute.$__export.read (http://localhost:9090/node_modules/angular/dist/js/prod/es6/angular2/src/core/compiler/directive_metadata_reader.es6!eval:31:41)
    at eval (http://localhost:9090/node_modules/angular/dist/js/prod/es6/angular2/src/core/compiler/compiler.es6!eval:127:35)
    at Array.map (native)
    at Function.System.register.execute.$__export.map (http://localhost:9090/node_modules/angular/dist/js/prod/es6/angular2/src/facade/collection.es6!eval:172:26)
    at Compiler.System.register.execute.$__export.createSteps (http://localhost:9090/node_modules/angular/dist/js/prod/es6/angular2/src/core/compiler/compiler.es6!eval:126:43)
    at Compiler.System.register.execute.$__export._compileTemplate (http://localhost:9090/node_modules/angular/dist/js/prod/es6/angular2/src/core/compiler/compiler.es6!eval:164:53)
    at eval (http://localhost:9090/node_modules/angular/dist/js/prod/es6/angular2/src/core/compiler/compiler.es6!eval:154:29)
    at Zone.run (http://localhost:9090/node_modules/zone.js/zone.js:87:19)

-----async gap-----
Error
    at Function.System.register.execute.$__export.then (http://localhost:9090/node_modules/angular/dist/js/prod/es6/angular2/src/facade/async.es6!eval:35:28)
    at Compiler.System.register.execute.$__export._compile (http://localhost:9090/node_modules/angular/dist/js/prod/es6/angular2/src/core/compiler/compiler.es6!eval:153:42)
    at Compiler.System.register.execute.$__export.compile (http://localhost:9090/node_modules/angular/dist/js/prod/es6/angular2/src/core/compiler/compiler.es6!eval:134:34)
    at eval (http://localhost:9090/node_modules/angular/dist/js/prod/es6/angular2/src/core/application.es6!eval:73:23)
    at Function.System.register.execute.$__export.apply (http://localhost:9090/node_modules/angular/dist/js/prod/es6/angular2/src/facade/lang.es6!eval:317:23)

-----async gap-----
Error
    at _AsyncInjectorStrategy.System.register.execute._AsyncInjectorStrategy.instantiate (http://localhost:9090/node_modules/angular/dist/js/prod/es6/angular2/src/di/injector.es6!eval:297:17)
    at Injector.System.register.execute.$__export._getByKey (http://localhost:9090/node_modules/angular/dist/js/prod/es6/angular2/src/di/injector.es6!eval:138:33)
    at Injector.System.register.execute.$__export.asyncGet (http://localhost:9090/node_modules/angular/dist/js/prod/es6/angular2/src/di/injector.es6!eval:112:25)
    at eval (http://localhost:9090/node_modules/angular/dist/js/prod/es6/angular2/src/core/application.es6!eval:113:39)

-----async gap-----
Error
    at VmTurnZone.System.register.execute.$__export._createInnerZone (http://localhost:9090/node_modules/angular/dist/js/prod/es6/angular2/src/core/zone/vm_turn_zone.es6!eval:61:45)
    at new VmTurnZone (http://localhost:9090/node_modules/angular/dist/js/prod/es6/angular2/src/core/zone/vm_turn_zone.es6!eval:29:34)
    at _createVmZone (http://localhost:9090/node_modules/angular/dist/js/prod/es6/angular2/src/core/application.es6!eval:101:16)
    at bootstrap (http://localhost:9090/node_modules/angular/dist/js/prod/es6/angular2/src/core/application.es6!eval:110:16)
    at y.main (http://localhost:9090/app.js!eval:10:12)
    at http://localhost:9090/?:42:21

-----async gap-----
Error
    at VmTurnZone.System.register.execute.$__export._createInnerZone (http://localhost:9090/node_modules/angular/dist/js/prod/es6/angular2/src/core/zone/vm_turn_zone.es6!eval:61:25)
    at new VmTurnZone (http://localhost:9090/node_modules/angular/dist/js/prod/es6/angular2/src/core/zone/vm_turn_zone.es6!eval:29:34)
    at _createVmZone (http://localhost:9090/node_modules/angular/dist/js/prod/es6/angular2/src/core/application.es6!eval:101:16)
    at bootstrap (http://localhost:9090/node_modules/angular/dist/js/prod/es6/angular2/src/core/application.es6!eval:110:16)
    at y.main (http://localhost:9090/app.js!eval:10:12)
    at http://localhost:9090/?:42:21

无法理解错误消息的含义，而且我也无法找到定义的form指令的位置。

更新：＆＃39; undefined＆＃39;实际上是一种形式＆＃39;在angular2 / modules / angular2 / src / forms中似乎缺少的指令。然后DirectiveMetadataReader传递未定义的＆＃39;进一步到反射器，最终导致例外。很高兴在模板中办理登机手续。

Answer 1

看起来Victor的博客中的示例与您使用的版本不匹配（API当时变化如此之快）。但是现在beta已经发布了（这意味着没有更多的重大变化）所以我创建了尽可能接近功能的工作示例：

Angular 2 Beta

import {Component} from 'angular2/core'
import {ControlGroup, FormBuilder, Validators} from 'angular2/common'
...

http://plnkr.co/edit/ae1WEgQJWPMdEgoweMGd?p=preview 只是为了检查它走了多远（足够了！）。

来自Angular版本：2.0.0-rc.1

使用angular2的所有导入都需要更改为@angular

import {Component} from '@angular/core'
import {ControlGroup, FormBuilder, Validators} from '@angular/common';

有关更多进口清单，请参阅此处： -

List of all imports updated to angular2 RC.

导入anuglar2 /表单导致“无法读取未定义的属性'注释”

1 个答案: