KeyValuePipe
将 Object 或 Map 转换为键值对数组。
Transforms Object or Map into an array of key value pairs.
{{ input_expression | keyvalue [ : compareFn ] }}
Exported from
输入值
input | { [key: string]: V; [key: number]: V; } | ReadonlyMap |
参数
compareFn | (a: KeyValue | 可选. 默认值是 `defaultComparator`. |
说明
输出数组将通过键名排序。默认情况下，比较器将使用 Unicode 点位值。如果你的键名是复杂类型，则可以选择传入一个 compareFn。
The output array will be ordered by keys. By default the comparator will be by Unicode point value. You can optionally pass a compareFn if your keys are complex types.
Further information available in the Usage Notes...
使用说明
例子
Examples
此示例演示了 ngFor 如何使用此键值管道对 Object 或 Map 进行迭代。
This examples show how an Object or a Map can be iterated by ngFor with the use of this keyvalue pipe.
@Component({
selector: 'keyvalue-pipe',
template: `<span>
<p>Object</p>
<div *ngFor="let item of object | keyvalue">
{{item.key}}:{{item.value}}
</div>
<p>Map</p>
<div *ngFor="let item of map | keyvalue">
{{item.key}}:{{item.value}}
</div>
</span>`
})
export class KeyValuePipeComponent {
object: {[key: number]: string} = {2: 'foo', 1: 'bar'};
map = new Map([[2, 'foo'], [1, 'bar']]);
}
