mobx可观察数组已更改，但渲染功能未重新运行

Question

@observer
export class BookshelfComponent extends React.Component<{}, {}> {
  @observable
  libraryData: ILibraryBook[] = [{isSelected: false}, {isSelected: false}];

  bookItemPress(index: number) {
    this.libraryData[index].isSelected = !this.libraryData[index].isSelected;
  }

  render() {
    return (

        <FlatList
          data={this.libraryData.slice()}
          renderItem={this.renderItem}
          numColumns={3}/>

    );
  }

  renderItem = ({item, index}) => {
    return (
      <LibraryItemComponent
        bookLibraryItem={item}
        itemClick={() => {
          this.bookItemPress(index)
        }}
      />
    );
  }

}

当我按下一个平面列表项目来调用bookItemPress功能时，render功能不会再次运行；

但是当我将一个项目推送到libraryData时，效果很好！

谢谢！

Answer 1

要更新@observable，您也可以

1. 在功能上使用动作装饰器。

  @action.bound
  bookItemPress(index: number) {
    this.libraryData[index].isSelected = !this.libraryData[index].isSelected;
  }

2. 使用runInAction

  bookItemPress(index: number) {
    runInAction(() => {
       this.libraryData[index].isSelected = !this.libraryData[index].isSelected;
    })
  }