previewPic(src, index) {
				let imgUrl = [];
				imgUrl.push(src);
				//预览
				uni.previewImage({
					urls: imgUrl,
					longPressActions: {
						itemList: ['保存图片'],
						success: function(data) {
						//云函数下载已上传至云开发的文件至临时文件
							uni.downloadFile({
								url: imgUrl[0],
								success: (res) => {
									if (res.statusCode === 200) {
										//保存图片到系统相册
										uni.saveImageToPhotosAlbum({
											filePath: res.tempFilePath,
											success: function() {
												uni.showToast({
													title: "保存成功",
													icon: "none"
												});
												return
											},
											fail: function() {
												uni.showToast({
													title: "保存失败，请稍后重试",
													icon: "none"
												});
												return
											}
										});
									}
								}
							})
						},
						fail: function(err) {
							console.log(err.errMsg);
						}
					}
				});
			}