在 React Native 中获取 TextInput 值和复选框状态

Question

我想检索用户名和密码的输入值以及复选框状态。我在 Whosebug 上找到了这个相关问题。但是当尝试实现这个时出现错误

'null' is not an object (evaluating 'this.state.username')

谁能帮我检索输入值和复选框状态，因为我是 React-native 的新手

代码：

var CheckBox = require('react-native-checkbox');
var Button = require('react-native-button');

var reactnative = React.createClass({

render: function() {
 return (
  <View style={styles.container}>

    <Text style={styles.signin}>Sign In</Text>

    <TextInput style={styles.logininput} ref= "username" onChangeText={(event) => this.setState({username:event.nativeEvent.text})} value={this.state.username}/>

    <TextInput style={styles.logininput} value="Password"/>

    <CheckBox label='Remeber Me' checked = {false} onClick={this._CheckBoxState}/>

    <Button style={styles.loginButton} onPress={this._handlePress.bind(this)}>
        Login
    </Button>

  </View>
  );
 },

 _handlePress(event) {
   //Get TextInput value
    var username= this.state.username;
    alert(username);
  },

 _CheckBoxState(event){
  //want to change the state from true to false or vice-versa

  }
});

Answer 1

您可能错过了在渲染前初始化初始状态函数。

 ...
 getInitialState: function() {
    return {username: ''};
 },
 render: function() {
  ....
 }

现在 this.state.username 应该可以访问了。

在 React Native 中获取 TextInput 值和复选框状态

Get TextInput Value and Checkbox state in React native

javascript

checkbox

textinput

react-native