NativeScript单向数据绑定不';t更新视图
这对我来说似乎是一个非常简单的案例,但我显然遗漏了一些东西。我有一个模型要绑定到视图。然后用Http调用加载模型。为什么视图不更新?我认为这就是单向绑定的全部意义 我已经验证了我正在从http调用中获取预期的数据 更新 我在屏幕上添加了一个按钮,数据绑定实际上会使用按钮按钮上两个字段的http加载数据更新屏幕,即使button方法只设置其中一个值。因此,要么NativeScript中存在错误,要么我没有做错事 更新2只需单击按钮即可触发绑定。我修改了代码,使之有一个空的tap处理程序,只需单击该按钮即可使其绑定 打字稿NativeScript单向数据绑定不';t更新视图,nativescript,angular2-nativescript,Nativescript,Angular2 Nativescript,这对我来说似乎是一个非常简单的案例,但我显然遗漏了一些东西。我有一个模型要绑定到视图。然后用Http调用加载模型。为什么视图不更新?我认为这就是单向绑定的全部意义 我已经验证了我正在从http调用中获取预期的数据 更新 我在屏幕上添加了一个按钮,数据绑定实际上会使用按钮按钮上两个字段的http加载数据更新屏幕,即使button方法只设置其中一个值。因此,要么NativeScript中存在错误,要么我没有做错事 更新2只需单击按钮即可触发绑定。我修改了代码,使之有一个空的tap处理程序,只需单击该
import { Component, ChangeDetectionStrategy, OnInit } from "@angular/core";
import { Job } from "../../shared/customer/job";
import { Http, Headers, Response } from "@angular/http";
import { Observable } from "rxjs/Rx";
@Component({
selector: "my-app",
templateUrl: "pages/job-details/job-details.html",
changeDetection: ChangeDetectionStrategy.OnPush
})
export class JobDetailsComponent implements OnInit {
job: Job;
salesAssociateName: string = "x";
constructor(private http: Http) {
this.job = new Job();
}
ngOnInit() {
this.getJob(1234);
}
getJob(leadId: number) {
var url = "https://url-not-for-you/job?franchiseeid=48&leadid=" + leadId;
var headers = this.createRequestHeader();
this.http.get(url, { headers: headers }).map(response => response.json())
.do(data => this.setData(data[0]))
.subscribe(
() => this.success(),
(error) => this.error()
);
}
private createRequestHeader() {
let headers = new Headers();
headers.append("AuthKey","blah");
headers.append("AuthToken", "blee");
return headers;
}
setData(job) {
this.job.FullName = job["FullName"];
this.job.SalesAssociateName = job["SalesAssociateName"];
this.salesAssociateName = this.job.SalesAssociateName;
console.log("Found job for customer: " + job["FullName"]);
}
success() {
// nothing useful
}
error() {
alert("There was a problem retrieving your customer job.");
}
changeSA() {
}
}
html
使用默认的ChangeDetectionStrategy,您的代码将按预期工作。但是,您已将策略更改为onPush 为了使您的绑定按照默认changeStrategy中的预期工作,请删除以下行
changeDetection: ChangeDetectionStrategy.OnPush
或者改成
changeDetection: ChangeDetectionStrategy.Default
更多关于Angular-2 ChangeDetection策略和
如果您仍然希望使用onPush而不是默认策略,那么您的属性应该声明为@input(),并且一旦进行了更改(在setData中),就用标记
当从按钮点击触发时,绑定工作的原因是
应用程序状态更改可以通过以下方式触发:
- 事件-轻按、轻扫、
- XHR-从远程服务器获取数据
- 计时器-例如setTimeout()
import { Component, ChangeDetectionStrategy, ChangeDetectorRef, OnInit, NgZone, Input } from "@angular/core";
import { Http, Headers, Response } from "@angular/http";
import { Observable as RxObservable } from "rxjs/Rx";
import "rxjs/add/operator/map";
import "rxjs/add/operator/do";
@Component({
selector: "my-app",
templateUrl: "app.component.html",
changeDetection: ChangeDetectionStrategy.OnPush
})
export class AppComponent implements OnInit {
@Input() public job: any = { salesAssociateName: "default job" };
@Input() public salesAssociateName: string = "default name";
constructor(private http: Http, private change:ChangeDetectorRef) { }
ngOnInit() {
this.getJob();
}
getJob() {
var url = "http://httpbin.org/get";
var headers = this.createRequestHeader();
this.http.get(url, { headers: headers })
.map(response => response.json())
.do(data => {
this.setData();
}).subscribe(
() => this.success(),
(error) => this.error()
);
}
private createRequestHeader() {
let headers = new Headers();
return headers;
}
setData() {
this.job.salesAssociateName = "NEW job SalesAssociateName";
this.salesAssociateName = "NEW job FullName";
this.change.markForCheck();
}
success() {
alert("success");
}
error() {
alert("There was a problem retrieving your customer job.");
}
}
您的代码将使用默认的ChangeDetectionStrategy按预期工作。但是,您已将策略更改为onPush 为了使您的绑定按照默认changeStrategy中的预期工作,请删除以下行
changeDetection: ChangeDetectionStrategy.OnPush
或者改成
changeDetection: ChangeDetectionStrategy.Default
更多关于Angular-2 ChangeDetection策略和
如果您仍然希望使用onPush而不是默认策略,那么您的属性应该声明为@input(),并且一旦进行了更改(在setData中),就用标记
当从按钮点击触发时,绑定工作的原因是
应用程序状态更改可以通过以下方式触发:
- 事件-轻按、轻扫、
- XHR-从远程服务器获取数据
- 计时器-例如setTimeout()
import { Component, ChangeDetectionStrategy, ChangeDetectorRef, OnInit, NgZone, Input } from "@angular/core";
import { Http, Headers, Response } from "@angular/http";
import { Observable as RxObservable } from "rxjs/Rx";
import "rxjs/add/operator/map";
import "rxjs/add/operator/do";
@Component({
selector: "my-app",
templateUrl: "app.component.html",
changeDetection: ChangeDetectionStrategy.OnPush
})
export class AppComponent implements OnInit {
@Input() public job: any = { salesAssociateName: "default job" };
@Input() public salesAssociateName: string = "default name";
constructor(private http: Http, private change:ChangeDetectorRef) { }
ngOnInit() {
this.getJob();
}
getJob() {
var url = "http://httpbin.org/get";
var headers = this.createRequestHeader();
this.http.get(url, { headers: headers })
.map(response => response.json())
.do(data => {
this.setData();
}).subscribe(
() => this.success(),
(error) => this.error()
);
}
private createRequestHeader() {
let headers = new Headers();
return headers;
}
setData() {
this.job.salesAssociateName = "NEW job SalesAssociateName";
this.salesAssociateName = "NEW job FullName";
this.change.markForCheck();
}
success() {
alert("success");
}
error() {
alert("There was a problem retrieving your customer job.");
}
}
实际上,在nativescript中,
onPush
,可观察到的输入不起作用或有时起作用。不知道为什么。这种方法现在在NativeScript 5.1和angular 7中仍然有效吗?事实上,可观察的输入不起作用,或者在NativeScript中的onPush
中不时起作用。不知道为什么。这个方法现在在NativeScript 5.1和angular 7中仍然有效吗?