我正在创建一个备份应用程序,其中 C# 扫描一个目录。 以前我使用下面的代码来获取目录中所有文件和子文件:
DirectoryInfo di = new DirectoryInfo("A:\\");
var directories= di.GetFiles("*", SearchOption.AllDirectories);
foreach (FileInfo d in directories)
{
//Add files to a list so that later they can be compared to see if each file
// needs to be copid or not
}
唯一的问题是有时候文件无法访问,我会得到多个错误。一个我遇到的错误示例如下:![error](https://istack.dev59.com/5YH4D.webp)
try
{
files = di.GetFiles(searchPattern, SearchOption.TopDirectoryOnly);
}
catch
{
//info of this folder was not able to get
lstFilesErrors.Add(sDir(di));
return;
}
这个方法很好用,唯一的问题是当我扫描一个大目录时,它需要太长时间。如何加速这个过程?如果需要,这是我的实际方法。
private void startScan(DirectoryInfo di)
{
//lstFilesErrors is a list of MyFile objects
// I created that class because I wanted to store more specific information
// about a file such as its comparePath name and other properties that I need
// in order to compare it with another list
// lstFiles is a list of MyFile objects that store all the files
// that are contained in path that I want to scan
FileInfo[] files = null;
DirectoryInfo[] directories = null;
string searchPattern = "*.*";
try
{
files = di.GetFiles(searchPattern, SearchOption.TopDirectoryOnly);
}
catch
{
//info of this folder was not able to get
lstFilesErrors.Add(sDir(di));
return;
}
// if there are files in the directory then add those files to the list
if (files != null)
{
foreach (FileInfo f in files)
{
lstFiles.Add(sFile(f));
}
}
try
{
directories = di.GetDirectories(searchPattern, SearchOption.TopDirectoryOnly);
}
catch
{
lstFilesErrors.Add(sDir(di));
return;
}
// if that directory has more directories then add them to the list then
// execute this function
if (directories != null)
foreach (DirectoryInfo d in directories)
{
FileInfo[] subFiles = null;
DirectoryInfo[] subDir = null;
bool isThereAnError = false;
try
{
subFiles = d.GetFiles();
subDir = d.GetDirectories();
}
catch
{
isThereAnError = true;
}
if (isThereAnError)
lstFilesErrors.Add(sDir(d));
else
{
lstFiles.Add(sDir(d));
startScan(d);
}
}
}
如果我尝试使用类似以下方式处理异常,那么问题就出现了:
DirectoryInfo di = new DirectoryInfo("A:\\");
FileInfo[] directories = null;
try
{
directories = di.GetFiles("*", SearchOption.AllDirectories);
}
catch (UnauthorizedAccessException e)
{
Console.WriteLine("There was an error with UnauthorizedAccessException");
}
catch
{
Console.WriteLine("There was antother error");
}
如果发生异常,那么我就得不到任何文件。
UnauthorisedAccessException
),否则编程错误(例如NullReferenceException
)和系统错误(例如OutOfMemoryException
)将被掩盖为应用程序错误。 - Paul Ruane