微信小程序下载视频或者照片或者文件到本地相册中

/**

* 下载单个文件
*/
function downloadFile(type, url, successc, failc) {
checkAuth(() => {
wx.showLoading({
title: '正在下载',
mask: true
})
downloadSaveFile(
type,
url,
() => {
wx.hideLoading();
wx.showToast({
title: '下载成功',
icon: 'none',
})
successc && successc();
},
(errMsg) => {
wx.hideLoading();
wx.showToast({
title: errMsg,
icon: 'none',
})
failc && failc();
}
);
})
}

/**
* 下载多个文件
*/
function downloadFiles(type, urls, completec) {
let success = 0;
let fail = 0;
let total = urls.length;
let errMsgs = [];

checkAuth(() => {
wx.showLoading({
title: '正在下载',
mask: true
})
for (let i = 0; i < urls.length; i++) {
downloadSaveFile(
type,
urls[i],
() => {
success++;
if (success + fail === total) {
saveCompleted(success, fail, completec, errMsgs);
}
},
(errMsg) => {
fail++;
errMsg && errMsgs.push(`视频${i}${errMsg}`);
if (success + fail === total) {
saveCompleted(success, fail, completec, errMsgs);
}
}
);
}
})
}

//保存完成
function saveCompleted(success, fail, completec, errMsgs) {
wx.hideLoading();
let errMsg = '无';
if (errMsgs.length) {
errMsg = errMsgs.join(' ');
}

wx.showModal({
title: `成功${success}项，失败${fail}项`,
content: `失败信息: ${errMsg}`,
showCancel: false,
success(res) {
if (res.confirm) {
completec && completec();
}
}
})
}

//下载文件
function downloadSaveFile(type, url, successc, failc) {
wx.downloadFile({
url: url,
success: res => {
if (res.statusCode === 200) {
if (type === 'video') {
//类型为视频
wx.saveVideoToPhotosAlbum({
filePath: res.tempFilePath,
success: res => {
successc && successc();
},
fail: res => {
failc && failc('保存失败');
}
})
} else if (type === 'image') {
//类型为图片
wx.saveImageToPhotosAlbum({
filePath: res.tempFilePath,
success: res => {
successc && successc();
},
fail: res => {
failc && failc('保存失败');
}
})
}else if(type==='file'){
wx.saveFile({
tempFilePath: res.tempFilePath,
success(res) {
const savedFilePath = res.savedFilePath
console.log(res)
}
})
}
} else {
failc && failc('状态码非200');
}
},
fail: res => {
failc && failc('下载失败');
}
})
}

//检查权限
function checkAuth(gotc) {
//查询权限
wx.showLoading({
title: '检查授权情况',
mask: true
})
wx.getSetting({
success(res) {
wx.hideLoading();
if (!res.authSetting['scope.writePhotosAlbum']) {
//请求授权
wx.authorize({
scope: 'scope.writePhotosAlbum',
success() {
//获得授权，开始下载
gotc && gotc();
},
fail() {
wx.showModal({
title: '',
content: '保存到系统相册需要授权',
confirmText: '授权',
success(res) {
if (res.confirm) {
wx.openSetting({
success(res) {
if (res.authSetting['scope.writePhotosAlbum'] === true) {
gotc && gotc();
}
}
})
}
},
fail() {
wx.showToast({
title: '打开设置页失败',
icon: 'none',
})
}
})
}
})
} else {
//已有授权
gotc && gotc();
}
},
fail() {
wx.hideLoading();
wx.showToast({
title: '获取授权失败',
icon: 'none',
})
}
})
}

module.exports = {
downloadFile,
downloadFiles
};