Angular 在component.ts中使用管道

我有一个管道来转换货币，如下所示

import { Pipe, PipeTransform } from '@angular/core';
import { LocalStorageService } from 'storage.service';
import { CurrencyUpdate } from 'update';
import { Observable } from 'rxjs/Observable';

@Pipe({name: 'currConvert'})
export class CurrConvertPipe implements PipeTransform {
    errorMessage: string;

    constructor(private currencyStorage: LocalStorageService, private currencyConversion: CurrencyUpdate) {
    }

    transform(value: number, toCurrency: string, baseCurrency: string): any {
        if (toCurrency && baseCurrency) {
            const outputRate = this.currencyStorage.getCurrencyRate(baseCurrency, toCurrency);
            if (!outputRate) {
                return this.currencyConversion.getExchangeRate(toCurrency, baseCurrency).map((rate: any) => {
                    const currency = {
                        fromCurrency: baseCurrency,
                        toCurrency,
                        exchangeRate: rate
                    };
                    this.currencyStorage.saveCurrencies(currency);
                    return value * rate;
                }, (error: any) => this.errorMessage = error);
            } else {
                return Observable.of(value * outputRate);
            }
        }
    };

}

this.convertedPrice = CurrConvertPipe.prototype.transform(this.Price, this.selectedCurrency, this.movieticket.price.currency);

在component.html中使用时效果非常好。在一种情况下，我需要在

组件.ts中使用它，因此我按如下方式使用它

import { Pipe, PipeTransform } from '@angular/core';
import { LocalStorageService } from 'storage.service';
import { CurrencyUpdate } from 'update';
import { Observable } from 'rxjs/Observable';

@Pipe({name: 'currConvert'})
export class CurrConvertPipe implements PipeTransform {
    errorMessage: string;

    constructor(private currencyStorage: LocalStorageService, private currencyConversion: CurrencyUpdate) {
    }

    transform(value: number, toCurrency: string, baseCurrency: string): any {
        if (toCurrency && baseCurrency) {
            const outputRate = this.currencyStorage.getCurrencyRate(baseCurrency, toCurrency);
            if (!outputRate) {
                return this.currencyConversion.getExchangeRate(toCurrency, baseCurrency).map((rate: any) => {
                    const currency = {
                        fromCurrency: baseCurrency,
                        toCurrency,
                        exchangeRate: rate
                    };
                    this.currencyStorage.saveCurrencies(currency);
                    return value * rate;
                }, (error: any) => this.errorMessage = error);
            } else {
                return Observable.of(value * outputRate);
            }
        }
    };

}

this.convertedPrice = CurrConvertPipe.prototype.transform(this.Price, this.selectedCurrency, this.movieticket.price.currency);

这抛出了一个错误，即

错误类型错误：无法读取未定义的属性“getCurrencyRate”

我尝试创建管道实例，但它不允许我这样做。如何在TS内部消费？
您不能将转换方法用作静态。。。因为管道构造函数中有依赖项，这些依赖项可以从您的角度解析，您需要使用。您需要通过依赖项注入在组件中导入CurrConvertPipe的实例，就像在依赖项CurrencyUpdate和LocalStorageService的管道中一样。诸如此类：

@Component
class SomeComponent {
    constructor(private currConvertPipe: CurrConvertPipe ) { }
    method() {
        this.convertedPrice = this.currConvertPipe.transform(this.Price, this.selectedCurrency, this.movieticket.price.currency);
    }
}

希望这有帮助。
您不能将转换方法用作静态。。。因为管道构造函数中有依赖项，这些依赖项可以从您的角度解析，您需要使用。您需要通过依赖项注入在组件中导入CurrConvertPipe的实例，就像在依赖项CurrencyUpdate和LocalStorageService的管道中一样。诸如此类：

@Component
class SomeComponent {
    constructor(private currConvertPipe: CurrConvertPipe ) { }
    method() {
        this.convertedPrice = this.currConvertPipe.transform(this.Price, this.selectedCurrency, this.movieticket.price.currency);
    }
}

希望这有帮助。
酷！我应该查一下！无论如何，我在一个共享模块中使用了这个管道，但是组件仍然抱怨我应该在提供者下添加它。有什么想法吗？@Sajeetharan，因为管道不是DI系统的一部分！我应该查一下！无论如何，我在一个共享模块中使用了这个管道，但是组件仍然抱怨我应该在提供者下添加它。有什么想法吗？@Sajeetharan，因为管道不是DI系统的一部分