我是关于Facebook ReactJS和React-native的初学者,所以我开始编写一个教程的帮助,显示 how to share code between Android and iOS
本教程后面会实现一个按钮,用于切换状态。 不幸的是,这是用mixin制作的。我想用HOC组件来做。
原创混音
export default {
getInitialState() {
return {
pressed: false
}
},
handlePress() {
this.setState({pressed: !this.state.pressed});
}
}
以上mixin的原始电话
{ ...
render() {
const buttonStyle = [styles.button];
if (this.state.pressed) buttonStyle.push(styles.buttonPress);
return (
<TouchableOpacity onPress={this.handlePress.bind(this)} style={buttonStyle}>
<Text style={styles.text}>{this.props.text}</Text>
</TouchableOpacity>
)
}
}
reactMixin.onClass(Button, ButtonCommon);
export default Button;
我的HOC
export var ButtonComp = (ComposedComponent) => class extends Component {
constructor(props) {
super(props);
this.state = {pressed: false};
}
handlePress() {
this.setState({pressed: !this.state.pressed});
}
render() {
return <ComposedComponent {...this.props} data={this.state.pressed} />;
}
};
我的HOC使用情况
import { ButtonComp } from './button.common';
class Button extends Component {
render() {
const buttonStyle = [styles.button];
if (this.props.data) buttonStyle.push(styles.buttonPress);
return (
<TouchableOpacity onPress={this.handlePress.bind(this)} style={buttonStyle}>
<Text style={styles.text}>{this.props.text}</Text>
</TouchableOpacity>
)
}
}
export default ButtonComp(Button); // Enhanced component
当我执行上面的代码时,我收到以下错误(当调用this.handle时,所以在TouchableOpacity标记中):
undefined不是对象(评估'this.handlePress.bind')
那么我做错了什么? HOC只传递数据,而不是函数吗? 谢谢你的帮助!
答案 0 :(得分:6)
HOC无法做到这一点。但是,如果您希望通过this
在包裹的组件中使用HOC中的某个功能,则必须通过props
传递它:
export var ButtonComp = (ComposedComponent) => class extends Component {
constructor(props) {
super(props);
this.state = {pressed: false};
this.handlePress = this.handlePress.bind(this);
}
handlePress() {
this.setState({pressed: !this.state.pressed});
}
render() {
return <ComposedComponent {...this.props} handlePress={this.handlePress} data={this.state.pressed} />;
}
};
class Button extends Component {
render() {
const buttonStyle = [styles.button];
if (this.pressed) buttonStyle.push(styles.buttonPress);
return (
<TouchableOpacity onPress={this.props.handlePress} style={buttonStyle}>
<Text style={styles.text}>{this.props.text}</Text>
</TouchableOpacity>
)
}
}