ionic3——更新app

参考：https://www.cnblogs.com/BetterMyself/p/7116235.html
过程中遇到了几个问题：
1、更新下载进度时，要控制更新速度，也就是进度就算后发生变化，才改变显示；

//下载的进度
    let newProgress = 0;
    fileTransfer.onProgress((progress)=>{
      /*{"bubbles":false,"cancelBubble":false,"cancelable":false,"lengthComputable":true,"loaded":1278957,"total":43921184,"target":null}*/
      let downloadProgress = Math.floor((progress.loaded / progress.total) * 100);
      //发现进度发生改变，更新显示
      if(newProgress != downloadProgress){
        newProgress = downloadProgress;

        //同步修改loading显示的进度值
        this.zone.run(() => {
          loadProgress.setContent("下载："+newProgress+"%");
        });

        console.log("newProgress:"+newProgress);
        //大于99结束显示
        if (downloadProgress > 99) {
          loadProgress.dismiss();
        }
      }

    });

2、ionic3中LoadingController多次create会弹出多个，需要创建一个，动态修改显示内容

let loadProgress = this.loadingCtrl.create({
      spinner: 'ios',
      content: "下载：0%",
      cssClass: "loadingProgress"
    });
    loadProgress.present();

//触发修改
//import { NgZone } from '@angular/core';
//constructor(private zone: NgZone) {}
this.zone.run(() => {
       loadProgress.setContent("下载："+newProgress+"%");
 });

3、修改LoadingController样式，已经spinner颜色等

image.png

.loading-md .loading-wrapper {
  max-width: 90%;
  max-height: 90%;
  color: white;
  font-size: 1.2rem;
  background: var(--main);//替换
  display: flex;
  justify-content: center;
  align-items: center;
}
.loadingProgress{
  .spinner-ios line {
    stroke: #9e9e9e;
  }
}