uniapp 微信小程序保存图片到系统相册（包括获取手机相册权限）即拿即用

1. 代码，即拿即用

const savePosterPath = (url) => {
	uni.showLoading({
		title: '正在保存图片...'
	});
	//获取用户的当前设置。获取相册权限
	uni.getSetting({
		success: (res) => {
			//如果没有相册权限
			if (!res.authSetting["scope.writePhotosAlbum"]) {
				//向用户发起授权请求
				uni.authorize({
					scope: "scope.writePhotosAlbum",
					success: () => {
						//授权成功保存图片到系统相册
						uni.saveImageToPhotosAlbum({
							//图片路径，不支持网络图片路径
							filePath: url,
							success: (res) => {
								uni.hideLoading();
								return uni.showToast({
									title: "保存成功！",
								});
							},
							fail: (res) => {
								console.log(res.errMsg);
								return uni.showToast({
									title: res.errMsg,
								});
							},
							complete: (res) => {uni.hideLoading();},
						});
					},
					//授权失败
					fail: () => {
						uni.hideLoading();
						uni.showModal({
							title: "您已拒绝获取相册权限",
							content: "是否进入权限管理，调整授权？",
							success: (res) => {
								if (res.confirm) {
			//调起客户端小程序设置界面，返回用户设置的操作结果。（重新让用户授权）
									uni.openSetting({
										success: (res) => {
										console.log(res.authSetting);
										},
									});
								} else if (res.cancel) {
									return uni.showToast({
										title: "已取消！",
									});
								}
							},
						});
					},
				});
			} else {
				//如果已有相册权限，直接保存图片到系统相册
				uni.saveImageToPhotosAlbum({
					filePath: url,
					success: (res) => {
						uni.hideLoading();
						return uni.showToast({
							title: "保存成功！",
						});
					},
					fail: (res) => {
						uni.hideLoading();
						console.log(res.errMsg);
						return uni.showToast({
							title: res.errMsg,
						});
					},
					//无论成功失败都走的回调
					complete: (res) => {uni.hideLoading();},
				});
			}
		},
		fail: (res) => {},
	});
};

2. 介绍使用到的方法

1. uni.getSetting

uniapp官网链接： https://uniapp.dcloud.io/api/other/setting.html#getsetting

2. uni.authorize

链接：https://uniapp.dcloud.io/api/other/authorize.html#authorize

3. uni.saveImageToPhotosAlbum

链接： https://uniapp.dcloud.io/api/media/image.html#saveimagetophotosalbum

4. uni.openSetting

链接： https://uniapp.dcloud.io/api/other/setting.html#opensetting