[英]Exception on Extracting the Zip file in C#
我正在使用在Winrt中使用C#的提取代碼來提取Zip文件。
我在這里從本地驅動器獲取文件:
StorageFile file = await KnownFolders.PicturesLibrary.GetFileAsync("dostoyevsky-poor-folk.zip");
Stream zipMemoryStream = await file.OpenStreamForReadAsync();
var folder = ApplicationData.Current.LocalFolder;
// Create zip archive to access compressed files in memory stream
using (ZipArchive zipArchive = new ZipArchive(zipMemoryStream, ZipArchiveMode.Read))
{
// For each compressed file...
foreach (ZipArchiveEntry entry in zipArchive.Entries)
{
if (entry.Name == "")
{
// Folder
await CreateRecursiveFolder(folder, entry);
}
else
{
// File
await ExtractFile(folder, entry);
}
}
}
我在這里提取文件夾:
private async Task CreateRecursiveFolder(StorageFolder folder, ZipArchiveEntry entry)
{
var steps = entry.FullName.Split('/').ToList();
steps.RemoveAt(steps.Count() - 1);
foreach (var i in steps)
{
await folder.CreateFolderAsync(i, CreationCollisionOption.OpenIfExists);
folder = await folder.GetFolderAsync(i);
}
}
我在這里提取文件:
private async Task ExtractFile(StorageFolder folder, ZipArchiveEntry entry)
{
var steps = entry.FullName.Split('/').ToList();
steps.RemoveAt(steps.Count() - 1);
foreach (var i in steps)
{
folder = await folder.GetFolderAsync(i);
}
using (Stream fileData = entry.Open())
{
StorageFile outputFile = await folder.CreateFileAsync(entry.Name, CreationCollisionOption.ReplaceExisting);
using (Stream outputFileStream = await outputFile.OpenStreamForWriteAsync())
{
await fileData.CopyToAsync(outputFileStream);
await outputFileStream.FlushAsync();
}
}
}
當我嘗試使用此方法時,出現以下異常: 'System.NullReferenceException' 。 異常獲取行是await outputFileStream.FlushAsync();
的最后一行await outputFileStream.FlushAsync();
有時,當我嘗試從本地驅動器中選擇文件時,也會遇到相同的異常。 在獲取異常之前, await outputFileStream.FlushAsync()
Debugger的值如下: await outputFileStream.FlushAsync()
。
你能幫我嗎
謝謝
最后,它對我有用。 為什么因為提取時獲取Null值,因為要提取文件的軟件包。 我確信這是使用c#為Windows應用商店提取Zip文件的完美解決方案。 謝謝
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