How to get latest files in C#
- by Newbie
I have some files with same name but with different dates.
Basically we are finding the files with most recent dates
The file patterns are
<FileNames><YYYYMMDD><FileExtension>
e.g. test_20100506.xls indicates
<FileNames> = test_
<YYYYMMDD> = 20100506
<FileExtension> = .xls
Now in the source folder, the files are
standardization_20100503.xls,
standardization_20100504.xls,
standardization_20100305.xls,
replacement_20100505.xls
As can be seen that, standardization_.xls are 3 in numbers but
replacement_.xls is only 1.
The output will be a list of file names whose content will be
standardization_20100504.xls and replacement_20100505.xls
Because among all the standardization_.xls is the most recent one and replacement_.xls is also the same.
I have tried with my own logic but somehow failed.
My idea is as under
private static void GetLatestFiles(ref List<FileInfo> validFiles)
{
List<FileInfo> validFilesTemp = new List<FileInfo>();
for (int i = 0; i < validFiles.Count; i++)
{
for (int j = i+1; j < validFiles.Count; j++)
{
string getFileTextX = ExtractText(validFiles[i].Name);
string getFileTextY = ExtractText(validFiles[j].Name);
if (getFileTextX == getFileTextY)
{
int getFileDatesX = Convert.ToInt32(ExtractNumbers(validFiles[i].Name));
int getFileDatesY = Convert.ToInt32(ExtractNumbers(validFiles[j].Name));
if (getFileDatesX > getFileDatesY)
{
validFilesTemp.Add(validFiles[i]);
}
else
{
validFilesTemp.Add(validFiles[j]);
}
}
}
}
validFiles.Clear();
validFiles = validFilesTemp;
}
The ExtractNumbers is:
public static string ExtractNumbers(string expr)
{
return string.Join(null, System.Text.RegularExpressions.Regex.Split(expr, "[^\\d]"));
}
and the ExtractText is
public static string ExtractText(string expr)
{
return string.Join(null, System.Text.RegularExpressions.Regex.Split(expr, "[\\d]"));
}
I am using c#3.0 and framework 3.5
Help needed .. it's very urgent
Thanks .
