提交按钮需要点击 2 次才能在 React 中调用函数

Question

当我点击提交按钮时，它需要点击才能正确触发该功能。在实施 if 语句之前我没有遇到问题。我有 2 个 if 语句，每次点击后它只检查 1 个 if 语句吗？

  onSubmit = (e) => {

const { firstName, lastName, email, eventDate, validation} = this.state

if (firstName, lastName, eventDate, email) {
  this.setState({validation: true})
  if (new RegExp(/[a-z0-9._%+-]+@[a-z0-9.-]+\.[a-z]{2,15}/g).test(email)) {
    this.setState({validation: true})
  } else {
    this.setState({validation: false})
    this.setState({errorMessage: 'Please enter correct email adress'})
  }
} else {
  this.setState({validation: false});
  this.setState({errorMessage: 'Please fill in all fields properly'})
} 

if (validation) {

  const newEvent = {
    firstName: this.state.firstName,
    lastName: this.state.lastName,
    email: this.state.email,
    eventDate: this.state.eventDate
  }

  this.props.addEvent(newEvent);

  this.setState({
    firstName: '',
    lastName: '',
    email: '',
    eventDate: '',
    validation: false,
    errorMessage: ''
  });
}

e.preventDefault();
}

Answer 1

您也不应该需要在彼此之后直接调用两个 setState。像这样将它们放在一个 setState 中：

this.setState({ 验证：假，错误消息：'Please enter correct email adress'， )}

Answer 2

我认为您在 if(validation) 语句中使用了过时的验证值。你能试试这样的东西吗：

onSubmit = (e) => {

const { firstName, lastName, email, eventDate} = this.state

if (firstName, lastName, eventDate, email) {
  this.setState({validation: true})
  if (new RegExp(/[a-z0-9._%+-]+@[a-z0-9.-]+\.[a-z]{2,15}/g).test(email)) {
    this.setState({validation: true})
  } else {
    this.setState({validation: false})
    this.setState({errorMessage: 'Please enter correct email adress'})
  }
} else {
  this.setState({validation: false});
  this.setState({errorMessage: 'Please fill in all fields properly'})
} 

const {validation} = this.state // read correct validation.. not something that was previously set

if (validation) {

  const newEvent = {
    firstName: this.state.firstName,
    lastName: this.state.lastName,
    email: this.state.email,
    eventDate: this.state.eventDate
  }

  this.props.addEvent(newEvent);

  this.setState({
    firstName: '',
    lastName: '',
    email: '',
    eventDate: '',
    validation: false,
    errorMessage: ''
  });
}

e.preventDefault();
}

Answer 3

解决了这个问题，他们成功的关键是将我的 if(validation) 语句主体移动到 setState 的回调函数。

这是工作代码：

  onSubmit = (e) => {
const { firstName, lastName, email, eventDate, validation} = this.state

if (firstName, lastName, eventDate, email) {
  this.setState({validation: true})
  if (new RegExp(/[a-z0-9._%+-]+@[a-z0-9.-]+\.[a-z]{2,15}/g).test(email)) {
    this.setState({validation: true}, () => {
      const newEvent = {
        firstName: firstName,
        lastName: lastName,
        email: email,
        eventDate: eventDate
      }
      this.props.addEvent(newEvent);

      this.setState({
        firstName: '',
        lastName: '',
        email: '',
        eventDate: '',
        validation: false,
        errorMessage: ''
      })
    })
  } else {
    this.setState({validation: false, errorMessage: 'Please enter correct email adress'})
  }
} else {
  this.setState({validation: false, errorMessage: 'Please fill in all fields properly'})
}
e.preventDefault();
}

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