如何从本地的反馈中获取其他组件的this.state.value [英] How do I get a this.state.value from other components in react native

问题描述

我把它从classone中调用classtwo中的getValue，但是还有另一种方法呢？有没有更简单的方法来从classtwo获取this.state.value？

I got it to work calling getValue in classtwo from classone but is there another way of doing this? Is there a easier way to get this.state.value from classtwo?

我尝试将静态getValue放在静态，但总是会给我一个错误。任何人都可以帮忙

I tried putting static getValue as static but it always throw me an error. Anyone can help?

谢谢！

class ClassOne extends React.Component {

    constructor(props) {
        super(props);

        this.state = {
            classtwo: new ClassTwo(),
        };
    }

    CallGetValue(){
        this.state.classtwo.getValue();
    }
}

class ClassTwo extends React.Component {

    constructor(props) {
        super(props);

        this.state = {
            value: 100,
        };

    }

    getValue(){
        return this.state.value;
    }
}

推荐答案

应该看起来像这样。

    class ClassOne extends React.Component {

        constructor(props) {
            super(props);

            this.state = {
                classtwo: 0,
            };
        }
            componentWillReceiveProps(nextProps) {
                if (nextProps.classtwo && (this.state.classtwo != nextProps.classtwo))
                    {this.setState({classtwo: nextProps.classtwo});}
            }
    }

    class ClassTwo extends React.Component {

        constructor(props) {
            super(props);
                    this.changeValue = this. changeValue.bind(this);
            this.state = {
                value: 100,
            };

        }

        changeValue(value){
            this.props.changeValue(this.state.value);
                    this.setState(value: value);
        }
    }

    class ClassZero extends React.Component {
        constructor(props) {
                super(props);
                this.changeValue = this. changeValue.bind(this);
                this.state = {
                        classTwoValue: 0,
                };

        }

        changeValue(value){
                this.setState(classTwoValue: value);
        }

        render() {
            return (
                <div>
                    <ClassOne classtwo={this.state.classTwoValue}/>
                    <ClassTwo changeValue={this.changeValue}/>
                </div>
            )
        }
    }

这篇关于如何从本地的反馈中获取其他组件的this.state.value的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持IT屋！