uni.saveFile 買步變同步

        myDownload_btn() {  
            let tmpDict = {}  //空字典,用於保存{ "原本檔案名" : "保存檔案名" }  

            const urlList = [ //要下載的url array  
                'https://ns-strategy.cdn.bcebos.com/ns-strategy/upload/fc_big_pic/part-00270-3760.jpg',  
                'https://ss0.bdstatic.com/70cFvHSh_Q1YnxGkpoWK1HF6hhy/it/u=1947872534,1823906830&fm=26&gp=0.jpg',  
                'https://ss3.bdstatic.com/70cFv8Sh_Q1YnxGkpoWK1HF6hhy/it/u=1034074796,4011346817&fm=26&gp=0.jpg'  
            ]  

            const myDownload = (url_index) => {  //參考教學的sleep  
                return new Promise(resolve => {  
                    let urlAddress = urlList[url_index]  
                    uni.downloadFile({  
                        url:urlAddress,  
                        success:(res)=>{  
                            console.log('DL sucess,tmpPath = ',res.tempFilePath)  
                            uni.saveFile({  
                                tempFilePath:res.tempFilePath,  
                                success: (savedRes) => {  
                                    tmpDict[url_index] = savedRes.savedFilePath //更新tmpDict的內容  
                                    resolve() //釋放promise鎖<< 我自己定義,python也有類似東西  
                                }  
                            })  
                        }  
                    })  
                })  
            }  
            const myJob = (url_index) => {    //參考教學的getNumFruit   
                return myDownload(url_index).then(v => urlList[url_index])  
            }  
            const control = async _ => {  
                console.log('Start')  
                for (let i = 0;i<3;i++){  
                    let DL_Job = await myJob(i)  
                }  
                console.log(tmpDict)  
                console.log('End')  
            }  

            control() //程序入口  
        },