如何将prop值分配给react中的状态

时间:2015-05-06 11:48:47

标签: reactjs babeljs

我有一个从另一个React组件启动的叠加层,它有一个也会自行更改的按钮。当用户单击按钮时,会发生更改,然后按钮会更改其类名。它还向作为叠加层的子组件发送prop值。叠加层根据属性添加一个类,如果单击它。 Everthing工作得很好,但现在我必须做另外一件事。当用户点击叠加层时,它必须关闭。在此更改之前,所有内容都适用于我之前提到的按钮。

这是按钮组件:

export default class StatusBarButton extends React.Component {

    constructor(props) {
        super(props)
        this.state = {active: false}
        this.handleClick = this.handleClick.bind(this)
    }

    handleClick() {
        this.setState({ active: !this.state.active });
    }

    render() {
        var cx = require('classnames');
        var button = cx ({
            'statusbar-button-container' : true,
            'active' : this.state.active
        });
        var animation = cx ({
            'statusbar-button-cross-image' : true,
            'rotate' : true,
            'active' : this.state.active
        });

        return (
            <div className="astatusbar-center-wrapper">
                <div className={button} onClick={this.handleClick}>
                    <img src="images/navbar-element-icon-cross.png" className={animation}/>
                </div>      
                <OverlayView isOpen={this.state.active} />
            </div>
        );
    }
}

目前这是Overlay:

export default class OverlayView extends React.Component {
    constructor (props){
        super(props);
        this.state = {open: false}
        this.setState({ open: this.props.isOpen });
    }



    render() {
        var cx = require('classnames');
        var overlay = cx({
            'overlay': true,
            'overlay-slidedown': true,
            'open': this.state.open
        });

        return (    
            <div className={overlay} onClick={this._closeOverlay}>
                <div className="overlay-menu-wrapper">
                    <OverlayNewInvoiceButton />
                    <OverlayNewBudgetButton />
                    <OverlayNewTicketButton />
                </div>
            </div>
        );
    }
}

如你所见,我正在尝试获取道具值并将其分配给州,但它无效。如何将prop值分配给状态并使用它?

此致 JP

4 个答案:

答案 0 :(得分:7)

您在OverlayView组件中缺少componentWillReceiveProps(props)方法。

export default class OverlayView extends React.Component {
    constructor (props){
        super(props);
        this.state = {open: props.isOpen}
    }

    componentWillReceiveProps(props) {
        this.setState({open: props.isOpen});
    }

    render() {
        let open = '';
        if (this.state.open === true) {
            open = 'open';
        }

        let overlayClass = `overlay overlay-slidedown ${open}`;

        return (    
            <div className={overlayClass} onClick={this._closeOverlay}>
                <div className="overlay-menu-wrapper">
                    <span>{open}</span>
                </div>
            </div>
       );
    }
}

完整的工作示例: https://codesandbox.io/s/35wLR4nA

答案 1 :(得分:1)

您的问题可能是您尝试使用mysqli_insert_id获取类道具。我认为你应该使用传递给构造函数的props。

像这样:

this

不确定为什么你不能在这样的一行中这样做:constructor (props){ super(props); this.state = {open: false} this.setState({ open: props.isOpen }); }

答案 2 :(得分:1)

最后我保留了改变班级的属性,并不是那么糟糕。我在这个问题的帮助下修复了Pass props to parent component in React.js,当然还有工作伙伴的帮助。最终版本是这样的:

这是父母:

export default class StatusBarButtonView_Profit extends React.Component {

    constructor(props) {
        super(props)
        this.state = {active: false}
        this._openOverlay = this._openOverlay.bind(this)
        this._closeOverlay = this._closeOverlay.bind(this)
    }

    _openOverlay() {
        if (this.state.active == false) {
            this.setState({ active: true });
            console.log('boton lanza overlay');
        } else {
            this.setState({ active: false });
            console.log('boton cierra overlay');
        }
    }

    _closeOverlay(Overlay) {
        if (this.state.active == true) {
            this.setState({ active: false });

        } else {
            this.setState({ active: true });
        }
    }

    render() {
        var cx = require('classnames');
        var button = cx ({
            'aui-profit-statusbar-button-container' : true,
            'active' : this.state.active
        });
        var animation = cx ({
            'aui-profit-statusbar-button-cross-image' : true,
            'rotate' : true,
            'active' : this.state.active
        });

        return (
            <div className="aui-profif-statusbar-center-wrapper">
                <div className={button} onClick={this._openOverlay}>
                    <img src="images/aui-navbar-element-icon-cross.png" className={animation}/>
                </div>      
                <OverlayView_Profit isOpen={this.state.active} onClick={this._closeOverlay}/>
            </div>
        );
    }
}

这是孩子:

export default class OverlayView_Profit extends React.Component {
    constructor (props){
        super(props);

    }

    _closeOverlay() {
        this.props.onClick();
    }

    render() {
        var cx = require('classnames');
        var overlay = cx({
            'aui-overlay': true,
            'aui-overlay-slidedown': true,
            'open': this.props.isOpen
        });

        return (    
            <div className={overlay} onClick={this._closeOverlay.bind(this)}>
                <OverlayNewInvoiceButtonView_Profit />
                <OverlayNewBudgetButtonView_Profit />
                <OverlayNewTicketButtonView_Profit />
            </div>
        );
    }
}

现在一切正常。

答案 3 :(得分:0)

constructor(props, context) {
    super(props, context);
     this.state = {
           value: ''
      };
   }

   componentWillReceiveProps(){ //this is called to before render method
    this.setState({
       value:this.props.data
     })