ValueProvider
配置此 Injector
以返回令牌的值。
Configures the Injector
to return a value for a token.
interface ValueProvider extends ValueSansProvider {
provide: any
multi?: boolean
// 继承自 core/ValueSansProvider
useValue: any
}
参见
属性
属性 | 说明 |
---|---|
provide: any | 注入令牌。通常是 An injection token. Typically an instance of |
multi?: boolean | 如果为 true,则注入器返回实例数组。这对于允许多个提供者散布在多个文件中以向公共令牌提供配置信息很有用。 When true, injector returns an array of instances. This is useful to allow multiple providers spread across many files to provide configuration information to a common token. |
使用说明
例子
Example
const injector = Injector.create([{provide: String, useValue: 'Hello'}]);
expect(injector.get(String)).toEqual('Hello');
Multi-value example
const locale = new InjectionToken<string[]>('locale');
const injector = Injector.create([
{provide: locale, multi: true, useValue: 'en'},
{provide: locale, multi: true, useValue: 'sk'},
]);
const locales: string[] = injector.get(locale);
expect(locales).toEqual(['en', 'sk']);