mobx入门

改变 observables状态

1. action

接上面案例，添加action到类中：

class Store{
  @observable arr = [];
  @observable obj = {a: 1};
  @observable map = new Map();

  @observable str = 'hello';
  @observable num = 123;
  @observable bool = false;

  @computed get result(){
    return this.str + this.num;
  }

  @action bar(){
    this.str = 'world';
    this.num = 40;
  }
}
const store = new Store();

//调用action，只会执行一次
store.bar();

2. action.bound

action.bound 可以用来自动地将动作绑定到目标对象。

class Store{
  @observable arr = [];
  @observable obj = {a: 1};
  @observable map = new Map();

  @observable str = 'hello';
  @observable num = 123;
  @observable bool = false;

  @computed get result(){
    return this.str + this.num;
  }

  @action bar(){
    this.str = 'world';
    this.num = 40;
  }

  //this 永远都是正确的
  @action.bound foo(){
    this.str = 'world';
    this.num = 40;
  }
}

const store = new Store();
setInterval(store.foo, 1000)

3. runInAction

action 只能影响正在运行的函数，而无法影响当前函数调用的异步操作。如果你使用async function来处理业务，那么我们可以使用 runInAction 这个API来解决这个问题。

@action async fzz() {
  await new Promise((resolve) => { 
    setTimeout(() => {
      resolve({
        num: 220,
        str: 'world'
      })
    }, 1000) 
  })
  runInAction(()=>{
    store.num = 220
    store.str = 'world'
  })    
}