从选择器中反应本机值

Question

文档：https://facebook.github.io/react-native/docs/picker

构造函数：

constructor(props) {        
  super(props);         
  this.state = {            
      showPass: true,
      press: false,
      email: "",
      age: 0,
      sexe:"",
      password: "",
      confirmPass: ""       
     } 
  }

JSX：

<Picker
    selectedValue={this.state.sexe}
    onValueChange={(value) => {this.setState({sexe: value})}}>
    <Picker.Item label="Homme" value="homme" />
    <Picker.Item label="Femme" value="femme" />
</Picker>

问题：我不知道为什么 this.state.sexe 没有受到影响

PS : React Native 初学者

Answer 1

您应该在状态上指定默认选择，然后只有 onValueChange 会触发

试试下面的代码

  constructor(props) {        
  super(props);         
  this.state = {            
      showPass: true,
      press: false,
      email: "",
      age: 0,
      sexe:"homme",
      password: "",
      confirmPass: ""       
     } 
  }

和 JSX

<Picker
    selectedValue={this.state.sexe}
    onValueChange={(value) => {this.setState({sexe: value})}}>
    <Picker.Item label="Homme" value="homme" />
    <Picker.Item label="Femme" value="femme" />
</Picker>

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