反应组件之间的动画过渡

Question

我想在两个组件之间进行动画处理，第一个组件淡出并从DOM中删除，然后再将下一个组件添加到DOM中并淡入。否则，新组件将添加到DOM中并占用空间。旧组件已删除。您可以在这个小提琴中看到问题：

http://jsfiddle.net/phepyezx/4

// css snippet
.switch-enter {
    opacity: 0.01;
}
.switch-enter.switch-enter-active {
    opacity: 1.0;
}
.switch-leave {
    opacity: 1.0;
}
.switch-leave.switch-leave-active {
    opacity: 0;
}

// React snippet 
<ReactCSSTransitionGroup transitionName="switch">
    <div key={key} className={className}>{this.text()}</div>
</ReactCSSTransitionGroup>

对于我来说，不可接受的解决方案是在转换为新组件之前用CSS隐藏原始组件，如下所示：

http://jsfiddle.net/phepyezx/5

// Change to css
.switch-leave {
    visibility: hidden;
    height: 0px;
    width: 0px;
    opacity: 1.0;
}

有没有办法在拆下原始组件之前“延迟”安装新组件的反应？我对速度或其他库持开放态度。

谢谢

Answer 1

使用componentWillUnmount()生命周期方法解决。

http://jsfiddle.net/phepyezx/9/

这是代码：

var ReactCSSTransitionGroup = React.addons.CSSTransitionGroup;

const Off = React.createClass({
    componentWillUnmount () {
        this.props.handleTransitionEnd();
    },
    render()  {
        return (
            <div className="off button">OFF</div>
        )
    }
});

const On = React.createClass({
    componentWillUnmount () {
        this.props.handleTransitionEnd();
    },
    render()  {
        return (
            <div className="on button">ON</div>
        )
    }
});

var Switch = React.createClass({
    getInitialState: function() {
        return {
            on: false,
            transitionEnd: true
        };
    },

    toggle: function(e) {
        this.setState({
            on: !this.state.on,
            transitionEnd: false
        });
    },

    handleTransitionEnd() {
        this.setState({transitionEnd: true});
    },

    renderOff() {
        if (! this.state.on && this.state.transitionEnd) {
            return (
                <Off key="off" handleTransitionEnd={this.handleTransitionEnd} />
            )
        }
    },

    renderOn() {
        if (this.state.on && this.state.transitionEnd) {
            return (
                <On key="on" handleTransitionEnd={this.handleTransitionEnd} />
            )
        }
    },

    render: function() {
        return (
            <div>
              <button onClick={this.toggle}>Toggle</button>
              <ReactCSSTransitionGroup transitionName="switch">
                {this.renderOff()}
                {this.renderOn()}
              </ReactCSSTransitionGroup>
            </div>
        );         
    }
});

React.render(<Switch/>, document.getElementById("switch"));

和相关的CSS：

.switch-enter {
    opacity: 0.01;
}
.switch-enter.switch-enter-active {
    opacity: 1.0;
    transition: opacity 500ms ease-in;
}
.switch-leave {
    opacity: 1.0;
}
.switch-leave.switch-leave-active {
    opacity: 0;
    transition: opacity 500ms ease-out;
}

您可以使用onnyBuchanan的答案获得相同的有效结果，该答案使用绝对定位和延迟而不是componentWillUnmount()