uniapp 预览、下载图片

			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);
						}
					}
				});
			}