实例代码：

import React, { Component , PropTypes} from 'react';
import {
AppRegistry,
StyleSheet,
Text,
View,
TextInput,
TouchableOpacity
} from 'react-native';

const DownButtonState = {
DownButtonActive : 0,
DownButtonDisable : 1,
}

// {id , startTime, deathCount}
var timeRecodes = []; //根据id来记录LCCountDownButton的信息

export default class DownButton extends Component {

// 构造  
constructor(props) {  
    super(props);  
    // 初始状态  
    this.state={  
        btnTitle:'默认'  
    }  
}

// static propTypes = {  
//     id:React.PropTypes.string,          //按钮的身份标识,同一个页面的按钮是同一个id  
//     beginText:React.PropTypes.string,   //初始状态按钮title  
//     endText:React.PropTypes.string,     //读秒结束后按钮的title  
//     count:React.PropTypes.number,       //计时数  
//     pressAction:React.PropTypes.func,   //按下按钮的事件,但是触发倒数需要你自己来调用方法  
//     changeWithCount:React.PropTypes.func,   //读秒变化的函数,该函数带有一个参数count,表示当前的剩余事件  
//     end:React.PropTypes.func,           //读秒完毕后的函数  
//     frameStyle:View.propTypes.style    //初始化的位置大小  
// }

buttonState = DownButtonState.DownButtonActive;

componentWillMount() {  
    this.shouldSetState = true;  
    this.state = {  
        btnTitle:this.props.beginText,  
    }  
}

componentDidMount() {  
    const {id,changeWithCount} = this.props;  
    for(var i = 0 ; i<timeRecodes.length ; i ++){  
        let obj = timeRecodes\[i\];  
        if (obj.id === id){  
            let liveTime = Date.now() - obj.startTime  
            if (liveTime < obj.deathCount \* 1000){  
                //避免闪动  
                let detalTime = Math.round(liveTime/1000);  
                let content = changeWithCount(obj.deathCount - detalTime);  
                this.setState({  
                    btnTitle:content  
                });  
                //手动调用倒计时  
                this.startCountDownWithCount(obj.startTime)  
            }  
        }  
    }

}

clearTime(){  
    if (this.interval){  
        clearInterval(this.interval)  
    }  
}

componentWillUnmount() {  
    this.shouldSetState = false;  
    this.clearTime();  
}

startCountDownWithCount(startTime){  
    this.buttonState = DownButtonState.DownButtonDisable;  
    const {changeWithCount,endText,count,end}= this.props;  
    this.startTime = startTime;  
    this.interval = setInterval(()=>{  
        let detalTime = Math.round((Date.now() - this.startTime)/1000);  
        let content = changeWithCount(count - detalTime);  
        if (detalTime >= count){  
            content = endText;  
            this.clearTime();  
            end && end();  
            this.buttonState = DownButtonState.DownButtonActive;  
        }  
        if(this.shouldSetState){  
            this.setState({  
                btnTitle:content  
            })  
        }  
    },1000)  
}

recordButtonInfo(){  
    const {id , count} = this.props;  
    var hasRecord = false;  
    for (var i = 0 ; i < timeRecodes.length ; i ++){  
        let obj = timeRecodes\[i\];  
        if(obj.id === id){  
            obj.startTime = Date.now();  
            hasRecord = true;  
            break;  
        }  
    }  
    if (!hasRecord){  
        let buttonInfo = {  
            id:id,  
            deathCount:count,  
            startTime:Date.now()  
        }  
        timeRecodes.push(buttonInfo)  
    }  
}

//外界调用  
startCountDown(){  
    this.startCountDownWithCount(Date.now());  
    this.recordButtonInfo();  
}

render(){  
    let isDisable = this.buttonState === DownButtonState.DownButtonDisable;  
    const {frameStyle} = this.props  
    return (  
        <TouchableOpacity disabled={isDisable}  
                          onPress={()=>{this.props.pressAction && this.props.pressAction()}}  
                          style={\[styles.buttonCommonStyle,isDisable?styles.disableButtonStyle:styles.activeButtonStyle,frameStyle\]}  
        >  
            <Text style={\[styles.txtCommonStyle,isDisable?styles.disableTxtStyle:styles.activeTxtStyle\]}>  
                {this.state.btnTitle}  
            </Text>  
        </TouchableOpacity>  
    );  
}

}

const styles = StyleSheet.create({

buttonCommonStyle:{  
    paddingRight:8,  
    paddingLeft:8,  
    paddingTop:8,  
    paddingBottom:8,  
    justifyContent:'center',  
    alignItems:'center'  
},  
//禁用时候的TouchableOpacity样式  
disableButtonStyle:{  
    // backgroundColor:'red',  
},  
//可以点击时候的TouchableOpacity样式  
activeButtonStyle:{  
    // backgroundColor:'green',  
},

txtCommonStyle:{  
    fontSize:14,  
},  
//禁用时候的Text样式  
disableTxtStyle:{  
    color:'#7189D0',  
},  
//可以点击时候的Text样式  
activeTxtStyle:{  
    color:'#767d72',  
}  

});

　　使用：

{this.onPressGetCode()}}
changeWithCount={(count)=> count + 's后重新获取'}
id='register'
ref={(e)=>{this.countDownButton=e}}
/>

　　代码源：https://www.cnblogs.com/pengsi/p/7681961.html