为什么在提交reactjs后清除TextBox

class MyForm extends React.Component {
  constructor(props) {
    super(props);
    this.state = {
      inputValue: ''
    };
  }

  handleSubmit = (event) => {
    event.preventDefault();
    // 处理表单提交逻辑
    // ...

    // 清除文本框
    this.setState({ inputValue: '' });
  }

  handleChange = (event) => {
    this.setState({ inputValue: event.target.value });
  }

  render() {
    return (
      <form onSubmit={this.handleSubmit}>
        <input
          type="text"
          value={this.state.inputValue}
          onChange={this.handleChange}
        />
        <button type="submit">提交</button>
      </form>
    );
  }
}

handleSubmit = (event) => {
  event.preventDefault();
  // 处理表单提交逻辑
  // ...

  // 清除文本框
  document.getElementById('myInput').value = '';
}

render() {
  return (
    <form onSubmit={this.handleSubmit}>
      <input
        id="myInput"
        type="text"
      />
      <button type="submit">提交</button>
    </form>
  );
}