使用setState与setParams反应Native [英] React Native using setState with setParams
问题描述
我正在开发一个本机应用程序,我希望能够从静态navigationOptions更改状态。我跟着这个: https://github.com/react-navigation/react -navigation / issues / 1789
I'm working on a react native app where I'd like to be able to change the state from the static navigationOptions. I was following this: https://github.com/react-navigation/react-navigation/issues/1789
并实施了以下解决方案之一:
And have implemented one of the solutions as follows:
static navigationOptions = ({navigation}) => {
const { state } = navigation;
const {params = {}} = navigation.state;
navigation.params = {title: "", description: "", points: 0, image: {}, saveImage: true};
return {
headerRight: ( <Button transparent onPress={()=> params.create()}><Icon name="ios-add" style={{color: 'white'}}/></Button>)
};
};
componentDidMount() {
this.props.navigation.setParams({
create: this.openCreateModal
});
}
openCreateModal() {
this.setState({createModalVisible:true});
}
不幸的是,当我按下按钮调用openCreateModal函数时,我收到错误 this.setState不是函数
。
Unfortunately when I call the openCreateModal function by pressing the button, I get the error this.setState is not a function
.
我很感激任何帮助。
推荐答案
您的 openCreateModal()
方法未绑定。在该问题上进一步了解并且有人指出那个错误。
Your openCreateModal()
method is not bound. Look further down in that issue and someone points out that mistake.
要解决此问题,您需要显式绑定它,以便它可以访问正确的 this
上下文,例如在你的构造函数中:
To fix this, you either need to explicitly bind it so it has access to the correct this
context, for example in your constructor:
constructor(props) {
super(props);
this.openCreateModal = this.openCreateModal.bind(this);
}
或者你可以将它转换成ES6箭头函数,它会自动绑定它像这样的类的上下文:
Or you can convert it to an ES6 arrow function which would auto-bind it to the class's context like so:
openCreateModal = () => {
this.setState({createModalVisible:true});
}
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