ionic3、Angular4 定时器的使用

// 声明变量
  applicationInterval:any; // 定时器
// 使用定时器，每秒执行一次
ionViewDidEnter(){
    let that = this;
    let applicationPageOpenData:number = parseInt(((new Date().getTime()/1000)+30).toString());
    let nowDte:number;
    this.nextBtnText = "30秒后方可点击"; // 按钮文本
    this.nextBtnBool = false; // 按钮是否可点击标识
    this.applicationInterval = setInterval(() => {
        nowDte = parseInt((new Date().getTime()/1000).toString());
        let receiveDate = applicationPageOpenData - nowDte;
        if(receiveDate>0){
          that.nextBtnText = receiveDate +"秒后方可点击";
        }else{
          that.nextBtnText = "下一步";
          that.nextBtnBool = true;
          // 停止定时器
          clearInterval(that.applicationInterval);
        }
    }, 1000);
}
// 本例，30秒后按钮方可点击