前段时间客户提了需求，要求批量下载文件，我的实现思路：
1.将文件下载到服务器的指定位置
2.打包压缩
3.下载
4.删除压缩包
考虑到如果压缩文件比较大，下载速度感人，所以用了异步，具体代码：
public async Task<IActionResult> GetSchoolEvidenceFiles(RongboRequest<FileQuery> request)
{
var url = "";
var query = new RongboRequest<SchoolCollectionItemQuery>()
{
Data = new SchoolCollectionItemQuery()
};
var planId = this.GetCurrentPlan().Id;
if (!string.IsNullOrWhiteSpace(request.Data.PlanningId)) {
planId = request.Data.PlanningId;
}
var endIndexs = _indexService.GetByPlanIdAllIndex(planId).Data;
if (!string.IsNullOrEmpty(request.Data.EndIndexId))
{
endIndexs = endIndexs.Where(p => p.Id == request.Data.EndIndexId).ToList();
}
if (request.Data.EndIndexs != null && request.Data.EndIndexs.Count() > 0)
{
endIndexs = endIndexs.Where(a => request.Data.EndIndexs.Contains(a.Id)).ToList();
}
var indexTypes = _typeService.GetAllBase().Data;
var indicatorCollections = _indicatorCollectionBll.GetAllBase().Data;
List<SchoolFileOutput1> schoolFileOutputList = new List<SchoolFileOutput1>();
SchoolFileOutput1 schoolFileOutput = new SchoolFileOutput1();
List<List<SchoolFileOutput1>> schoolFileOutputLists = new List<List<SchoolFileOutput1>>();
var schools = _schoolService.GetDataByExpression(a => request.Data.SchoolList.Contains(a.Id) && a.SystemId == SystemIdInt).Data;
//var files = _indexFileService.GetAllBase().Data;//获取佐证材料
var files = _indexFileService.GetDataByExpression(a => request.Data.SchoolList.Contains(a.SchoolId)).Data;
if (request.Data.EndIndexs != null && request.Data.EndIndexs.Count() > 0 )
{
files = files.Where(a => request.Data.EndIndexs.Contains(a.IndexId)).ToList();
}
List<List<ExpertiseIndexOutput>> TargetZzFiles = new List<List<ExpertiseIndexOutput>>();
List<ExpertiseIndexOutput> expertiseIndexOutputList = new List<ExpertiseIndexOutput>();
ExpertiseIndexOutput expertiseIndexOutput = new ExpertiseIndexOutput();
foreach (var school in schools)
{
var schoolEndIndexs = endIndexs.Where(a => a.SchoolType.ToString() == school.SchoolType
&& (a.SchoolId == school.Id || a.SchoolId == "0")).ToList();
expertiseIndexOutputList = new List<ExpertiseIndexOutput>();
foreach (var endInex in schoolEndIndexs)
{
expertiseIndexOutput = new ExpertiseIndexOutput();
var indextype = indexTypes.Where(a => a.Id == endInex.IndexType).FirstOrDefault()?.Type == 3 ? true : false;//判断是否监测指标
var indicatorCollection = indicatorCollections.Where(a => a.EndIndexId == endInex.Id).Where(a => a.IsSchoolWrite == 1).Any();//判断指标是否配置需要学校填报的采集项
var usefiles = files.Where(m => m.SchoolId == school.Id && m.IndexId == endInex.Id).ToList();
if (usefiles.Count() > 0 && ((indextype && indicatorCollection) || !indextype))//判断指标是否需要上传佐证材料
{
expertiseIndexOutput.Files = usefiles.Select(m => new IndexFileOutput
{
Id = m.Id,
Name = m.Name,
Remark = m.Remark,
SchoolId = m.SchoolId,
Type = m.Type,
IndexId = m.IndexId
}).ToList();
expertiseIndexOutput.SchoolName = school.Name;
expertiseIndexOutput.SchoolId = school.Id;
expertiseIndexOutput.SchoolType = school.SchoolType;
expertiseIndexOutput.XM_ID = endInex.Id;
var endIndexEtity = endIndexs.Where(a => a.Id == endInex.Id).FirstOrDefault();
expertiseIndexOutput.Name = /*endIndexEtity?.Sort + "." + */endIndexEtity?.Name;
expertiseIndexOutputList.Add(expertiseIndexOutput);
}
}
TargetZzFiles.Add(expertiseIndexOutputList.OrderBy(a => a.Sort).ToList());
}
var aliossConfig = _fileService.GetAliOSSConfig();
OssClient client = new OssClient(aliossConfig.Endpoint, aliossConfig.AccessKeyId, aliossConfig.AccessKeySecret);
foreach (var item in TargetZzFiles)//多个指标学校佐证文件
{
schoolFileOutputList = new List<SchoolFileOutput1>();
foreach (var SchoolZzFiles in item)
{
if (SchoolZzFiles.Files.Any())
{
foreach (var file in SchoolZzFiles.Files)
{
schoolFileOutput = new SchoolFileOutput1();
var model = files.Where(a => a.Id == file.Id).FirstOrDefault() ?? new IndexFileEntity();
if (model == null || string.IsNullOrEmpty(file.Id))
{
return Json(RongboResult<string>.Failed(-1, "文件不存在"));
}
string savePath = (_webEnv.ContentRootPath + AppSetting.GetFilePath() + model.Path).Replace("\\", "/");
if (System.IO.File.Exists(savePath))
{
var fs = new FileStream(savePath, FileMode.Open, FileAccess.Read);
}
else
{
var type = model.Type;
schoolFileOutput.FileTypeName = file.Name;
schoolFileOutput.SchoolName = SchoolZzFiles.SchoolName;
schoolFileOutput.Id = SchoolZzFiles.Id;
schoolFileOutput.Name = SchoolZzFiles.Name;
if (!string.IsNullOrWhiteSpace(type) && (type == "image/jpeg" || type == "image/png" || type == "image/gif"))
{
type = "image/jpg";
}
if (client.DoesObjectExist(aliossConfig.BucketName, model.Path))
{
url = GeneratePresignedUri(client, aliossConfig.BucketName, model.Path, DateTime.Now.AddHours(1), type);
schoolFileOutput.Path = url;
schoolFileOutputList.Add(schoolFileOutput);
}
else if (client.DoesObjectExist(aliossConfig.BucketName, model.DistrictCode + "/" + model.Path))
{
url = GeneratePresignedUri(client, aliossConfig.BucketName, model.DistrictCode + "/" + model.Path, DateTime.Now.AddHours(1), type);
schoolFileOutput.Path = url;
schoolFileOutputList.Add(schoolFileOutput);
}
}
}
}
else
{
schoolFileOutput = new SchoolFileOutput1();
schoolFileOutput.SchoolName = SchoolZzFiles.SchoolName;
schoolFileOutput.FileTypeName = "";
schoolFileOutput.Id = SchoolZzFiles.Id;
schoolFileOutput.Name = SchoolZzFiles.Name;
schoolFileOutput.Path = "";
schoolFileOutputList.Add(schoolFileOutput);
}
}
schoolFileOutputLists.Add(schoolFileOutputList);
}
ApiResponse1<string> resultMessage = await DownTargetZzFile(schoolFileOutputLists);//压缩打包成zip格式文件
return Json(RongboResult<string>.Failed(resultMessage.state, resultMessage.message));
}
/// <summary>
/// OSS生成文件签名地址
/// </summary>
private string GeneratePresignedUri(OssClient client, string bucketName, string key, DateTime expiration, string type)
{
ResponseHeaderOverrides responseHeaders = new ResponseHeaderOverrides();
responseHeaders.ContentType = type;//"application/pdf"
var request = new GeneratePresignedUriRequest(bucketName, key, SignHttpMethod.Get)
{
Expiration = expiration,
ResponseHeaders = responseHeaders
};
return client.GeneratePresignedUri(request).ToString();
}
/// <summary>
/// 下载完成后删除压缩包
/// </summary>
/// <returns></returns>
public IActionResult DeleteZip(string schoolName)
{
try
{
string pathZip = Directory.GetCurrentDirectory() + "/file/" + schoolName + "佐证资料.zip";
if (System.IO.File.Exists(pathZip))
{
//Directory.Delete(pathZip);
System.IO.File.Delete(pathZip);
}
return Json("");
}
catch (Exception)
{
return Json("");
}
}以上，希望能够对各位有所帮助