when I add a picture I want it to create a new random name because if you add a picture with the same name it will just overwrite
You could generate a Guid and use that for your file name. Although this would mean that the files are not human readable and have no information as to what the content is.
You could built it using current time.
string fileName = DateTime.Now.ToString("yyyyMMddHHmmssfff") + ".png";
The above example will format the current time using Year, Month, Day, Hours, Minutes, Seconds, and Fractions of a second. (The fraction of a second can be specified with fewer f
s if you want down to one.).
Advantages:
- It will sort automatically by the created time in an alphabetically sorted list. ( like default sorting in file explorer ).
- It is human readable and provides useful info about the time it is created.
Disadvantages:
- If this is a web application (or other sort of multi-thread process) it is a (small) chance of two files getting same name if generated at the same time. This is not an issue if this is a single thread exe.
Name your image using a GUID
For C# you can use: System.Guid.NewGuid().ToString()
i would go with awe use original filename + DateTime.Now.ToString("yyyyMMddHHmmssffff");
As you want to save pictures, you could just use a GUID as the filename:
string filename = Path.Combine(Path.GetTempPath(), Guid.NewGuid() + ".jpg");
I always do it this way when I need another file extension than .tmp (which files get when you create them via GetTempFileName).
Of course you could create the files via GetTempFileName and then rename them, but then you have to check again if a file with the new name exists...
I would also go with the GUID solution.
Here some code I would use regularly:
public static string GetRandomFileName(string extension)
{
StringBuffer sb = new StringBuffer(Guid.NewGuid().ToString());
if (!string.IsNullOrEmpty(extensions))
{
sb.Append(".");
sb.Append(extension);
}
return sb.ToString();
}
Would provide you with a fine, reusable solution. Put this into your "collection of my greatest moments" - classlibrary and you are good to go.
The are built-in method Path.GetRandomFileName
. It returns a random folder name or file name.
The GetRandomFileName method returns a cryptographically strong, random string that can be used as either a folder name or a file name. Unlike GetTempFileName, GetRandomFileName does not create a file. When the security of your file system is paramount, this method should be used instead of GetTempFileName.
If you want to use your extension (e.g. .jpg
instead of generated), you could add it to generated file as:
string extension = ".jpg";
string fileName = Path.GetRandomFileName() + extension;