不要原地改变状态。它会导致意想不到的结果。我已经吸取教训了!总是使用复制/克隆，Object.assign()是一个很好的例子:

item = Object.assign({}, this.state.items[1], {name: 'newName'});
items[1] = item;
this.setState({items: items});

https://developer.mozilla.org/en/docs/Web/JavaScript/Reference/Global_Objects/Object/assign

尝试这肯定会工作，其他情况下我尝试过，但没有工作

import _ from 'lodash';

this.state.var_name  = _.assign(this.state.var_name, {
   obj_prop: 'changed_value',
});

我也有同样的问题。这里有一个简单的解决方法!

const newItems = [...this.state.items];
newItems[item] = value;
this.setState({ items:newItems });

下面这段代码对我迟钝的大脑来说很轻松。删除对象并替换为更新后的对象

    var udpateditem = this.state.items.find(function(item) { 
                   return item.name == "field_1" });
    udpateditem.name= "New updated name"                       
    this.setState(prevState => ({                                   
    items:prevState.dl_name_template.filter(function(item) { 
                                    return item.name !== "field_1"}).concat(udpateditem)
    }));

突变免费的:

// given a state
state = {items: [{name: 'Fred', value: 1}, {name: 'Wilma', value: 2}]}

// This will work without mutation as it clones the modified item in the map:
this.state.items
   .map(item => item.name === 'Fred' ? {...item, ...{value: 3}} : item)

this.setState(newItems)

以下是如何在没有帮助库的情况下做到这一点:

handleChange: function (e) {
    // 1. Make a shallow copy of the items
    let items = [...this.state.items];
    // 2. Make a shallow copy of the item you want to mutate
    let item = {...items[1]};
    // 3. Replace the property you're intested in
    item.name = 'newName';
    // 4. Put it back into our array. N.B. we *are* mutating the array here, 
    //    but that's why we made a copy first
    items[1] = item;
    // 5. Set the state to our new copy
    this.setState({items});
},

如果你愿意，你可以结合步骤2和3:

let item = {
    ...items[1],
    name: 'newName'
}

或者你可以用一行写完:

this.setState(({items}) => ({
    items: [
        ...items.slice(0,1),
        {
            ...items[1],
            name: 'newName',
        },
        ...items.slice(2)
    ]
}));

注意:我将项目创建为数组。OP使用一个对象。然而，概念是一样的。

你可以看到在你的终端/控制台发生了什么:

❯ node
> items = [{name:'foo'},{name:'bar'},{name:'baz'}]
[ { name: 'foo' }, { name: 'bar' }, { name: 'baz' } ]
> clone = [...items]
[ { name: 'foo' }, { name: 'bar' }, { name: 'baz' } ]
> item1 = {...clone[1]}
{ name: 'bar' }
> item1.name = 'bacon'
'bacon'
> clone[1] = item1
{ name: 'bacon' }
> clone
[ { name: 'foo' }, { name: 'bacon' }, { name: 'baz' } ]
> items
[ { name: 'foo' }, { name: 'bar' }, { name: 'baz' } ] // good! we didn't mutate `items`
> items === clone
false // these are different objects
> items[0] === clone[0]
true // we don't need to clone items 0 and 2 because we're not mutating them (efficiency gains!)
> items[1] === clone[1]
false // this guy we copied