Question

When i debug code with f10 IT WORKS with NO ERROR !.But on runtime i got this error:
“An item with the same key has already been added”

Plz help

My Dictionary :

public static Dictionary<string, string> ImageFilePath
        = new Dictionary<string, string>();

Using in same Glob.cs my function :

public static Image ShowImageOnColumn(string Value,byte ImageHeigth,byte ImageWidth)
{

   .
   .
   .

    string FilePath = "",ImgId = "";


    Image img_ = new Image();

    Random rnd = new Random();

    ImgId = rnd.Next(100000000).ToString();
    img_.ImageUrl = "ShowImageInRuntime.aspx?FileName=" + ImgId;

    ImageFilePath.Add(ImgId, FilePath);


    img_.Height = Unit.Pixel(ImageHeigth);
    img_.Width = Unit.Pixel(ImageWidth);

    return img_;

   }

Answer 1

You are not guarding your ImageFilePath.Add call. If the key already exists, you will get an exception saying as much.

You can do a check for a key:

if (ImageFilePath.ContainsKey(ImgId))
{
    ImageFilePath[ImgId] = FilePath;
}

Or you can set on the index, this will add if it’s missing and update if it exists:

ImageFilePath[ImgId] = FilePath;

As opposed to calling Add.

Note, however, that static members are liable to being lost when IIS recycles worker processes. Hence they tend to be avoided. There are also multi-threading issues as the static member is visible across the process.

If you need a random file name, try DateTime.ToString("ddMMyyyyhhmmssfff") or Guid.NewGuid(), as opposed to keeping an instance of Random alive.

Path also features a GetTempFileName method.