Angular 承诺解决后如何加载html页面?
我正在尝试使用Angular和Typescript从ASP.NET核心API向html组件显示一些数据,响应返回正确的值,承诺工作正常 问题是在解决承诺之前加载html页面,因此显示的值未定义 承诺解决后,我可以使用什么来加载页面?如何加载 fileshare.component.tsAngular 承诺解决后如何加载html页面?,angular,typescript,dependency-injection,promise,angular-resolver,Angular,Typescript,Dependency Injection,Promise,Angular Resolver,我正在尝试使用Angular和Typescript从ASP.NET核心API向html组件显示一些数据,响应返回正确的值,承诺工作正常 问题是在解决承诺之前加载html页面,因此显示的值未定义 承诺解决后,我可以使用什么来加载页面?如何加载 fileshare.component.ts export class FileShareComponent implements OnInit { constructor( private route: ActivatedRoute,
export class FileShareComponent implements OnInit {
constructor(
private route: ActivatedRoute,
private router: Router,
private service: UserService,
private http: HttpClient
) {
const file: string = this.route.snapshot.queryParamMap.get('file');
this.http.get(this.service.BaseURL + '/Share?IdentityString=' + file)
.toPromise()
.then(res => {
this.service.sharedFormData = res as ShareModel;
console.log(this.service.sharedFormData);
});
}
ngOnInit() {
}
}
<pre><code class="hljs">Name:
{{service.sharedFormData.Name}}</code></pre>
<pre><code class="hljs">Description:
{{service.sharedFormData.Description}}</code></pre>
<pre><code class="hljs">Syntax:
{{service.sharedFormData.Syntax}}</code></pre>
<pre><code class="hljs">LastModified:
{{service.sharedFormData.LastModified | date: "HH:mm dd/MM/yyyy"}}</code></pre>
<pre><code class="hljs">Content:
{{service.sharedFormData.Content}}</code></pre>
<div class="form-group text-center mt-4">
<button class="btn btn-dark" (click)="this.service.raw()" type="submit"><i class="fas fa-database"></i>
Raw</button>
</div>
fileshare.component.html
由于
FileShareComponent
是触发服务调用的组件,因此除非创建更复杂的嵌套组件体系结构,否则在该调用完成之前无法阻止组件初始化
我将隐藏这些值,直到可观察到的结果解决为止。我看不出有什么迫切的理由将可观察的转化为承诺。大概是这样的:
现在,只需将显示模板包装在一个隐藏的div中,直到加载数据:
名称:
{{service.sharedFormData.Name}
说明:
{{service.sharedFormData.Description}}
语法:
{{service.sharedFormData.Syntax}}
上次修改:
{{service.sharedFormData.LastModified}日期:“HH:mm dd/mm/yyyy”}
内容:
{{service.sharedFormData.Content}
未经加工的
根据你目前的结构,我认为这是最简单的方法。如果我是从头开始构建它,我会考虑使用。或者更简单地说,您可以在html模板中使用elvis操作符。 fileshare.component.html
名称:
{{service?.sharedFormData?.Name}
说明:
{{service?.sharedFormData?.Description}}
语法:
{{service?.sharedFormData?.Syntax}
上次修改:
{{服务?.sharedFormData?.LastModified |日期:“HH:mm dd/mm/yyyy”}
内容:
{{service?.sharedFormData?.Content}
未经加工的
您是否在
console.log(this.service.sharedFormData)中获取值代码>?尝试将this.changeDetectorRef.detectChanges()
放在then()
中this.service.sharedFormData=res之后阻塞为ShareModel代码>,但不应该是必需的。试一下,让我知道console.log(this.service.sharedFormData)中有值;但这些值在html请求后会显示在控制台中。现在我来看看路由器解析器。
export class ShareModel {
Id:number;
Name: string;
Description: string;
Syntax: string;
IdentityString:string;
LastModified: string;
Content: string;
FileId: number;
}
export class FileShareComponent implements OnInit {
// create a variable to determine whether screen is initialized
screenInitialized = false;
constructor(
private route: ActivatedRoute,
private router: Router,
private service: UserService,
private http: HttpClient
) {
const file: string = this.route.snapshot.queryParamMap.get('file');
this.http.get(this.service.BaseURL + '/Share?IdentityString=' + file)
// subscribe to Observable instead of converting it to a promise
.subscribe(res => {
this.service.sharedFormData = res as ShareModel;
// toggle initialized property
this.initialized = true;
console.log(this.service.sharedFormData);
});
}
ngOnInit() {
}
}
<div *ngIf="initialized">
<pre><code class="hljs">Name:
{{service.sharedFormData.Name}}</code></pre>
<pre><code class="hljs">Description:
{{service.sharedFormData.Description}}</code></pre>
<pre><code class="hljs">Syntax:
{{service.sharedFormData.Syntax}}</code></pre>
<pre><code class="hljs">LastModified:
{{service.sharedFormData.LastModified | date: "HH:mm dd/MM/yyyy"}}</code></pre>
<pre><code class="hljs">Content:
{{service.sharedFormData.Content}}</code></pre>
<div class="form-group text-center mt-4">
<button class="btn btn-dark" (click)="this.service.raw()" type="submit"><i class="fas fa-database"></i>
Raw</button>
</div>
</div>
<pre><code class="hljs">Name:
{{service?.sharedFormData?.Name}}</code></pre>
<pre><code class="hljs">Description:
{{service?.sharedFormData?.Description}}</code></pre>
<pre><code class="hljs">Syntax:
{{service?.sharedFormData?.Syntax}}</code></pre>
<pre><code class="hljs">LastModified:
{{service?.sharedFormData?.LastModified | date: "HH:mm dd/MM/yyyy"}}</code></pre>
<pre><code class="hljs">Content:
{{service?.sharedFormData?.Content}}</code></pre>
<div class="form-group text-center mt-4">
<button class="btn btn-dark" (click)="this.service.raw()" type="submit"><i class="fas fa-database"></i>
Raw</button>
</div>