[英]ASP.Net MVC displaying stored .zip files and allowing downloading from database
[英]Downloading files as a zip result in corrupted zips in ASP.NET MVC
我有一個托管大型XML文件存檔的服務器,並且API在zip中檢索所請求的文件。 如果我選擇大約11個或更少的文件,zip返回就好了。 如果我檢索更多,我在嘗試打開zip時收到以下錯誤:
“Windows無法打開文件夾。壓縮(壓縮)文件夾無效。”
以下是創建zip的數據類和方法:
//Archive file containing filename and content as memory stream
public class ArchiveFile {
public string FileName;
public System.IO.MemoryStream FileContent;
}
//Method to retrieve archive files and zip them
public static System.IO.MemoryStream GetFilesAsZip (string[] arrFileNames) {
MemoryStream zipStream = null;
using (zipStream = new MemoryStream()) {
// Retrieve files using above method
ArchiveFile[] retrievedFiles = GetFilesFromArchive(arrFileNames);
// Initialize new ZipArchive on the return object's MemoryStream property
using (ZipArchive archive = new ZipArchive(zipStream, ZipArchiveMode.Update, leaveOpen: true)) {
// Write file entries into archive
foreach (ArchiveFile dataFile in retrievedFiles) {
if (dataFile.FileContent != null) {
// Create new ZipArchiveEntry with content
ZipArchiveEntry zipEntry = archive.CreateEntry(dataFile.FileName);
dataFile.FileContent.WriteTo(zipEntry.Open());
}//end if
} // end foreach
} //end using
} //end using
return zipStream;
}//end method
//API to return content to user as an MVC File Content Result
[HttpGet]
public ActionResult DownloadFiles (string [] fileNames) {
FileContentResult data = new FileContentResult(GetFiles(fileNames).GetBuffer(), “application/zip”) { FileDownloadName = “files.zip” };
return data;
} //end method
在寫入內存流時,損壞可能與空間分配有關。 我注意到我所有的“成功”拉鏈(11個或更少的文件)大小為259 KB,但所有“不成功”的拉鏈(超過11個文件)大小為517 KB,一些較大的嘗試拉鏈大小為1034 KB。 這讓我感到非常巧合,因為它們都是258.5 KB的倍數,特別是因為11個文件的拉鏈產生了259 KB的拉鏈,但是12個文件的拉鏈產生了517 KB的拉鏈。
對它可能是什么的任何見解?
ASP.Net Core API Controller返回損壞的excel文件
在你的控制器中返回
return new FileResult("demo.zip", Path.Combine(sWebRootFolder, sFileName), "application/zip");
添加此代碼
public class FileResult : ActionResult
{
public FileResult(string fileDownloadName, string filePath, string contentType)
{
FileDownloadName = fileDownloadName;
FilePath = filePath;
ContentType = contentType;
}
public string ContentType { get; private set; }
public string FileDownloadName { get; private set; }
public string FilePath { get; private set; }
public async override Task ExecuteResultAsync(ActionContext context)
{
var response = context.HttpContext.Response;
response.ContentType = ContentType;
context.HttpContext.Response.Headers.Add("Content-Disposition", new[] { "attachment; filename=" + FileDownloadName });
using (var fileStream = new FileStream(FilePath, FileMode.Open))
{
await fileStream.CopyToAsync(context.HttpContext.Response.Body);
}
}
}
你的代碼被重構了
public byte[] GetFilesAsZip (string[] arrFileNames) {
byte[] buffer = null;
using (MemoryStream zipStream = new MemoryStream()) {
// Retrieve files using above method
ArchiveFile[] retrievedFiles = GetFilesFromArchive(arrFileNames);
// Initialize new ZipArchive on the return object's MemoryStream property
using (ZipArchive archive = new ZipArchive(zipStream, ZipArchiveMode.Update, leaveOpen: true)) {
// Write file entries into archive
foreach (ArchiveFile dataFile in retrievedFiles) {
if (dataFile.FileContent != null) {
// Create new ZipArchiveEntry with content
ZipArchiveEntry zipEntry = archive.CreateEntry(dataFile.FileName);
dataFile.FileContent.WriteTo(zipEntry.Open());
}//end if
} // end foreach
} //end using
buffer = zipStream.ToArray();
} //end using
return buffer;
}//end method
你應該能夠改變它
FileContentResult data = new FileContentResult(GetFiles(fileNames), “application/zip”) { FileDownloadName = “files.zip” };
我在過去做過return File(fileLocation, "application/zip", fileName);
已經成功了return File(fileLocation, "application/zip", fileName);
其中fileLocation是文件夾的路徑,fileName是實際文件夾的名稱。 您可以在ActionResult
執行此操作。
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