React Native ScrollView - 如何从另一个子组件按钮滚动到子组件?

2022-01-21 00:00:00 reactjs scrollview javascript components react-native

我有一个带有 ScrollView 的结构，它是一个有 5 个孩子的父级

I have this structure with a ScrollView, which is a parent with 5 childs

带有 ScrollView 的父组件

Parent Component with ScrollView

  • 组件1
  • 组件2
  • 组件3
  • 组件4
  • 组件5

在 Component3 内部，我有一个按钮，按下该按钮应将父组件 ScrollView 滚动到 Component5

Inside Component3 I have a button that when pressed should scroll parent component ScrollView to Component5

类似的东西

首页(父)

export default class Home extends React.Component {      
    renderComments() {
        return this.state.dataSource.map(item =>
            <CommentDetail key={item.id} comment={item} />
        );
    }

    render() {
        return (
            <ScrollView>      
                <Component1 />
                <Component2 />
                <CentralElements  {...this.state.dataSource} scroll = {this.props.scroll} />
                <Component4 />                  
                <View>
                    {this.renderComments()}
                </View>
            </ScrollView>
        );
    }
}

CentralElements (Component3)

export default class CentralElements extends React.Component {
    constructor(props) {
        super(props);
    }
  
    goToComments= () => {
        this.props.scroll.scrollTo({x: ?, y: ?, animated: true});
     };

    render() {
        return (
            <ScrollView horizontal={true}>
                <TouchableOpacity onPress={this.goToComments}>
                    <Image source={require('../../assets/image.png')} />
                    <Text>Comments</Text>
                </TouchableOpacity>
                ...
                </TouchableOpacity>
            </ScrollView>
        );
    }
};

评论是Component5，关于如何父滚动的任何想法?我试图弄清楚我错过了什么，因为那是我第一次接触这个.

And the Comments are the Component5, any idea on how to the parent scroll? I trying to figure what I'm missing, since thats my first contact with this.

推荐答案

我做的是..
在 component5 中，我在主视图中调用 onLayout，然后将 x 和 y 保存在父组件中.要在单击时在组件 3 中滚动到它，我调用父函数，该函数使用 scrollview ref 滚动到之前存储的值

What i did was..
in component5 I call onLayout in the main view and then save x and y in the parent component. To scroll to it in component 3 on click i call the parent function that uses the scrollview ref to scroll to the values stored before

组件5

    export default class Component5 extends Component {

    saveLayout() {
        this.view.measureInWindow((x, y, width, height) => {
            this.props.callParentFunction(x, y)
        })
    }
    render() {
        return (
            <View ref={ref => this.view = ref} onLayout={() => this.saveLayout()}>

            </View>
        )
    }
}

组件3

export default class Component3 extends Component {

    render() {
        return (
            <View >
                <TouchableOpacity onPress={()=>{this.props.goToComponent5()}}>

                </TouchableOpacity>
            </View>
        )
    }
}

家长:

export default class Parent extends Component {
constructor(props) {
this.goToComponent5=this.goToComponent5.bind(this)
    super(props)
    this.state = {
        x:0,
        y:0,
    }
}

    callParentFunction(x, y) {
        this.setState({ x, y })
    }

    goToComponent5(){
        this.ScrollView.scrollTo({x: this.state.x, y: this.state.y, animated: true});
    }

    render() {
        return (
            <View >
                <ScrollView ref={ref => this.ScrollView = ref}>
                    <Component1 />
                    <Component2 />
                    <Component3 goToComponent5={this.goToComponent5}/>
                    <Component4 />
                    <Component5 callParentFunction={this.callParentFunction}/>
                </ScrollView>
            </View>
        )
    }
}

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