Angular2 rc6表达在检查后发生了变化

Question

我已经按照http://almerosteyn.com/2016/04/linkup-custom-control-to-ngcontrol-ngmodel上的教程来创建自定义元素.

有一个包含两个字段的表单:一个自定义组件和另一个通过ngmodel链接到同一字段的组件(输入字段).

当我编辑自定义组件中的值时,它会抛出异常"ORIGINAL EXCEPTION:表达式在检查后已更改.".但是,正常字段中的更改会触发正确更改自定义元素.

这是代码:

<custom-component [control]="surname1" [(ngModel)]="person.surname1" [name]="'surname1'" formControlName="surname1">Add surname:</custom-component>

<input type="text" name="surname2" id="surname2" formControlName="surname1" [(ngModel)]="person.surname1" />

和自定义元素:

const noop = () => {};

export const CUSTOM_INPUT_CONTROL_VALUE_ACCESSOR: any = {
    provide: NG_VALUE_ACCESSOR,
    useExisting: forwardRef(() => MyInputComponent2),
    multi: true
};

@Component({
    selector: 'custom-component',
    template: `<label><ng-content></ng-content></label>
                    <input type="text"  name="{{name}}" [(ngModel)]="value" 
                        (ngModelChange)="changed($event)"

                        (blur)="onBlur()"
                    />
    `,
    providers: [CUSTOM_INPUT_CONTROL_VALUE_ACCESSOR]
})
export class CustomComponent implements ControlValueAccessor {

    @Input() control: FormControl;
    @Input() name: any;
    private innerValue: any = '';

    private onTouchedCallback: () => void = noop;
    private onChangeCallback: (_: any) => void = noop;

    //get accessor
    get value(): any {
        return this.innerValue;
    };

    //set accessor including call the onchange callback
    set value(v: any) {
        if (v !== this.innerValue) {
            this.innerValue = v;
            this.onChangeCallback(v);
        }
    }

    //Set touched on blur
    changed(event) {
        this.onTouchedCallback();
    }

    onBlur() {
        this.onTouchedCallback();
    }

    //From ControlValueAccessor interface
    writeValue(value: any) {
        if (value !== this.innerValue) {
            this.innerValue = value;
        }
    }

    //From ControlValueAccessor interface
    registerOnChange(fn: any) {
        this.onChangeCallback = fn;
    }

    //From ControlValueAccessor interface
    registerOnTouched(fn: any) {
        this.onTouchedCallback = fn;
    }
}

它在使用enableProdMode()时解决; 但不能在开发中使用它

****错误(Chrome输出):

core.umd.js:5995 EXCEPTION:./MFormComponent类中的错误MFormComponent - 内联模板:55:117引起:表达式在检查后发生了变化.以前的价值:'surtest'.当前价值:'surtes'.

core.umd.js:5997原始异常:表达式在检查后发生了变化.以前的价值:'surtest'.当前价值:'surtes'

在ExpressionChangedAfterItHasBeenCheckedError.Error(native)的ExpressionChangedAfterItHasBeenCheckedError.BaseError [作为构造函数](http:// localhost:8085/templatetest/js/@ angular/core/bundles/core.umd.js:1456:38)处于新的ExpressionChangedAfterItHasBeenCheckedError(http) :// localhost:8085 /templatetest/js/@angular/core/bundles/core.umd.js:8078:20)

Answer 1

我想这是因为你使用相同formControlName="surename1"的<custom-component>和<input>.
如果要将它们绑定到同一模型,则只指向ngModel它,但为每个模型创建一个控件.