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API > @angular/platform-browser

By

Predicates for use with DebugElement's query functions.

      
      class By {
  static all(): Predicate<DebugElement>
  static css(selector: string): Predicate<DebugElement>
  static directive(type: Type<any>): Predicate<DebugElement>
}

静态方法

all()

Match all elements.

static all(): Predicate<DebugElement>
      
      static all(): Predicate<DebugElement>
参数

没有参数。

返回值

Predicate<DebugElement>

使用说明

Example
debugElement.query(By.all());
      
      debugElement.query(By.all());

css()

Match elements by the given CSS selector.

static css(selector: string): Predicate<DebugElement>
      
      static css(selector: string): Predicate<DebugElement>
参数
selector string
返回值

Predicate<DebugElement>

使用说明

Example
debugElement.query(By.css('[attribute]'));
      
      debugElement.query(By.css('[attribute]'));

directive()

Match elements that have the given directive present.

static directive(type: Type<any>): Predicate<DebugElement>
      
      static directive(type: Type<any>): Predicate<DebugElement>
参数
type Type
返回值

Predicate<DebugElement>

使用说明

Example
debugElement.query(By.directive(MyDirective));
      
      debugElement.query(By.directive(MyDirective));