uni-app uploadFile 多次调用，无法获取所有上传任务的进度

循环调用uploadFile，获取到的uploadTask只有最后一个能够获取到上传进度

            uploadImage: function(e) {  
                console.log("uploadImage");  
                const tempFilePaths = this.imageList;  
                for (var i in tempFilePaths) {  
                    const tempFile = tempFilePaths[i];  
                    if (tempFile) {  
                        this.progress = this.progress || [];  
                        this.progress[i] = this.progress[i] || {percent:0, active :true};  
                        this.progress[i].uploadTask = uni.uploadFile({  
                            url: url, //仅为示例，非真实的接口地址  
                            // files: tempFilePaths, // 需要上传的文件列表。使用 files 时，filePath 和 name 不生效//仅5+APP支持  
                            filePath: tempFile,  
                            name: 'upload',  
                            formData: {  
                                'uploadUser': 'test',  
                                'uploadFileName': tempFile,  
                            },  
                            success: (uploadFileRes) => {  
                                console.log(uploadFileRes.data);  
                            },  
                            fail: (uploadFileRes) => {  
                                console.log(uploadFileRes);  
                            },  
                            complete: (uploadFileRes) => {  

                            }  
                        });  

                        const _this = this;  
                        this.progress[i].uploadTask.onProgressUpdate((res) => {  
                            console.log('上传进度' + res.progress);  
                            console.log('已经上传的数据长度' + res.totalBytesSent);  
                            console.log('预期需要上传的数据总长度' + res.totalBytesExpectedToSend);  
                            _this.progress[i].percent = res.progress;  
                            // 测试条件，取消上传任务。  
                            //                             if (res.progress > 50) {  
                            //                                 uploadTask.abort();  
                            //                             }  
                        });  
                    }  
                }  
            },