如何在C＃中创建随机图像名称？

Question

当我添加图片时，我希望它创建一个新的随机文件名，因为如果你添加一个具有相同名称的图片，它将只是覆盖。

Answer 1

The is a 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 (eg .jpg instead of generated), you could use another helper method Path.ChangeExtension :

string extension = ".jpg";
string fileName = Path.ChangeExtension(
    Path.GetRandomFileName(),
    extension
);

System.IO.Path.GetRandomFileName gets a file name that is guaranteed to be unique .

Answer 2

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...

Answer 3

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.

Answer 4

You could built it using the 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 it down to one.).

---

Advantages:

• It will sort automatically by the created time in an alphabetically sorted list. (Like default sorting in Windows Explorer.)
• It is human readable and provides useful information about the time it is created.

Disadvantages:

• If this is a web application (or other sort of multi-thread process) there 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.

Answer 5

Name your image using a GUID

For C# you can use: System.Guid.NewGuid().ToString()

Answer 6

也许您正在寻找GetTempFileName 。

Answer 7

I would go with awe . Use the original filename + DateTime.Now.ToString("yyyyMMddHHmmssffff"); .

Answer 8

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.