React setState object 键与条件事件目标

Question

我在设置 object 键状态时遇到问题。所以下面的代码是一个带有标题 body、城市和国家的表格。根据用户给出的值，我将它们设置为状态。但是由于国家和城市应该在 'address' object 中分配，我创建了一个处理程序来检查值是否为 country/city。

但结果即使不满足条件，ELSE是运行，仍然使用if条件中的object赋值

所以无论是标题还是城市，州都设置在地址中 object

你能检查一下我哪里做错了吗？

下面是我的表单和处理程序

class Postit extends Component {
  state = {
    title: "",
    body: "",
    address: {
      country: "",
      city: ""
    }
  };

  handleChange = e => {
    if (e.target.id === "country" || "city") {
      let address = Object.assign({}, this.state.address); 
      address[e.target.id] = e.target.value; 
      this.setState({ address });
      console.log("NewState", this.state);
   
    } else {
      console.log("Target is not city or country");
     this.setState({
        [e.target.id]: e.target.value
      });
    }
  };

  handleSubmit = e => {
    e.preventDefault();
    console.log(this.state);
  };
  render() {
    return (
      <div className="container">
        <form className="white" onSubmit={this.handleSubmit}>
          <h5 className="grey-text text-darken-3">Send your post</h5>
          {/* Title */}
          <div className="input-field">
            <input type="text" id="title" onChange={this.handleChange} />
            <label htmlFor="title"> Title</label>
          </div>
          {/* Body */}
          <div className="input-field">
            <textarea
              id="body"
              className="materialize-textarea"
              onChange={this.handleChange}
            />
            <label htmlFor="body"> Content</label>
          </div>
          {/* City / Country Select */}

          <div className="input-field">
            <input type="text" id="country" onChange={this.handleChange} />
            <label htmlFor="country"> Write your Country</label>
          </div>

          <div className="input-field">
            <input type="text" id="city" onChange={this.handleChange} />
            <label htmlFor="city"> Write your City</label>
          </div>

          <div className="input-field">
            <button
              className="btn pink lighten-1 center-align"
              style={{ marginTop: "10px", borderRadius: "6px", width: "100%" }}
            >
              Post it
            </button>
          </div>
        </form>
      </div>
    );
  }
}

例如，当我填写标题时，newState 如下所示：

{title: "", body: "", address: {country:"", city:"", title:"test"}}

谢谢！

Answer 1

您没有正确检查条件。 if (e.target.id === "country" || "city") 永远为真，即使 e.target.id 不是 "country"，因为 or 部分 "city" 是真值。应该是if (e.target.id === "country" || e.target.id === "city")

 handleChange = e => {
    if (e.target.id === "country" || e.target.id === "city") {
      let address = Object.assign({}, this.state.address); 
      address[e.target.id] = e.target.value; 
      this.setState({ address });
      console.log("NewState", this.state);

    } else {
      console.log("Target is not city or country");
     this.setState({
        [e.target.id]: e.target.value
      });
    }
  };

希望对您有所帮助！

React setState object 键与条件事件目标

React setState object key with conditional event target

object

event-handling

setstate

reactjs