为什么我的React表单提交值未定义?

时间:2018-11-04 14:10:23

标签: reactjs forms undefined

我正在尝试创建一个表单并将其值存储在状态中-到目前为止,如此合理。

我认为我已经把它设置好了,但是当我返回状态的内容时,每个字段都返回未定义状态。我毫不怀疑在设置过程中我忽略了一些简单的事情,但是我一生都无法看到它是什么...

有人可以让我摆脱痛苦吗?

handleAddProperty = (event) => {
  event.preventDefault();
  console.log(this.state.fields);
  console.log(this.state.fields.type);
};

handleFieldChange = (event) => {
    this.setState({
      fields: {
        title: event.target.value.title,
        type: event.target.value.type,
        bedrooms: event.target.value.bedrooms,
        bathrooms: event.target.value.bathrooms,
        price: event.target.value.price,
        city: event.target.value.city,
        email: event.target.value.email,
      },
    });
  };

 render() {
    return (
      <div className="addproperty">
        <form onSubmit={this.handleAddProperty}>
          <button type="submit">Add</button>
          <input name="title" value={this.state.fields.title} onChange={this.handleFieldChange} />
          <select name="type" value={this.state.fields.type} onChange={this.handleFieldChange}>
            <option value={this.state.fields.type}>Flat</option>
            <option value={this.state.fields.type}>Detached</option>
            <option value={this.state.fields.type}>Semi-Detached</option>
            <option value={this.state.fields.type}>Terraced</option>
            <option value={this.state.fields.type}>End of Terrace</option>
            <option value={this.state.fields.type}>Cottage</option>
            <option value={this.state.fields.type}>Bungalow</option>
          </select>
          <input name="bedrooms" value={this.state.fields.bedrooms} onChange={this.handleFieldChange} />
          <input name="bathrooms" value={this.state.fields.bathrooms} onChange={this.handleFieldChange} />
          <input name="price" value={this.state.fields.price} onChange={this.handleFieldChange} />
          <select name="city" value={this.state.fields.city} onChange={this.handleFieldChange}>
            <option value={this.state.fields.city}>Manchester</option>
            <option value={this.state.fields.city}>Leeds</option>
            <option value={this.state.fields.city}>Sheffield</option>
            <option value={this.state.fields.city}>Liverpool</option>
          </select>
          <input name="email" value={this.state.fields.email} onChange={this.handleFieldChange} />
        </form>
      </div>
    );
  }
}

1 个答案:

答案 0 :(得分:1)

您应该访问event.target.value而不是event.target.value[key],因为handleFieldChange函数会为每个输入字段(当它们更改状态时)以及每个触发event.target进行触发指的是其他输入字段(基本上是已更改的输入)。

要更新状态,可以使用event.target.name作为组件状态内表单对象成员的键。该代码可能如下所示:

 constructor(props) {
   super(props);
   this.state = { form: { name: 'Jane' } };
 }

 handleFieldChange(event) {
    // This will update specific key in your form object inside the local state
    this.setState({
      form: Object.assign({}, this.state.form, {
      [event.target.name]: event.target.value,
    }),
   });
 }


 <input
    name="test"
    type="text"
    onChange={e => this.handleFieldChange(e)}
 />