FontStream is not added properly to the PrivateFontCollection when more iterations are performed.

Question

We loaded three different font streams into a PrivateFontCollection, printed the names of each font family, and counted the number of fonts once after adding all the font streams.

We repeated this process 10 times. When adding these font streams continuously to the PrivateFontCollection for each iteration, sometimes a font was missing from the collection. For example, the collection sometimes showed only two fonts added.

Please provide me with a solution to have a consistent output using PrivateFontCollection.

Note: Our requirement is to add font stream into the private font collection.

Code snippet:

|string[] fontList = new string[] { @"arial.ttf", @"calibri.ttf", @"verdana.ttf" };
PrivateFontCollection fontCollection = null;
for (int i = 0; i < 10; i++)
{
 
fontCollection = new PrivateFontCollection();
foreach (string fontFile in fontList)
{
 
if (!File.Exists(fontFile)) continue;
Console.WriteLine("Font name: " + fontFile);
Stream fontStream = File.OpenRead(fontFile);
fontStream.Position = 0;
byte[] fontdata = new byte[fontStream.Length];
fontStream.Position = 0;
//read the font data from the ttf stream
fontStream.Read(fontdata,0, (int)fontStream.Length);
IntPtr data = Marshal.AllocCoTaskMem((int)fontStream.Length);
Marshal.Copy(fontdata,0, data, (int)fontStream.Length);
fontCollection.AddMemoryFont(data,(int)fontStream.Length);
}
Console.WriteLine("Total Number of fonts added in the
PrivateFontCollection: " + fontCollection.Families.Length);
for (int k = 0; k < fontCollection.Families.Length; k++)
Console.WriteLine(i

• " Iteration and
  families Name: " + k +
  " - " + fontCollection.Families[k].Name);
  fontCollection.Dispose();
  fontCollection
  = null;
  }| | -------- | ||

Actual Output:

 

Total Number of fonts added in the PrivateFontCollection: 3

0 Iteration and families Name: 0 - Arial

0 Iteration and families Name: 1 - Calibri

0 Iteration and families Name: 2 - Verdana

 

Total Number of fonts added in the PrivateFontCollection: 3

1 Iteration and families Name: 0 - Arial

1 Iteration and families Name: 1 - Calibri

1 Iteration and families Name: 2 - Verdana

 

Total Number of fonts added in the PrivateFontCollection: 3

2 Iteration and families Name: 0 - Arial

2 Iteration and families Name: 1 - Calibri

2 Iteration and families Name: 2 - Verdana

 

Total Number of fonts added in the PrivateFontCollection: 3

3 Iteration and families Name: 0 - Arial

3 Iteration and families Name: 1 - Calibri

3 Iteration and families Name: 2 - Verdana

 

Total Number of fonts added in the PrivateFontCollection: 3

4 Iteration and families Name: 0 - Arial

4 Iteration and families Name: 1 - Calibri

4 Iteration and families Name: 2 - Verdana

 

Total Number of fonts added in the PrivateFontCollection: 3

5 Iteration and families Name: 0 - Arial

5 Iteration and families Name: 1 - Calibri

5 Iteration and families Name: 2 - Verdana

 

Total Number of fonts added in the PrivateFontCollection: 3

6 Iteration and families Name: 0 - Arial

6 Iteration and families Name: 1 - Calibri

6 Iteration and families Name: 2 - Verdana

 

Total Number of fonts added in the PrivateFontCollection: 3

7 Iteration and families Name: 0 - Arial

7 Iteration and families Name: 1 - Calibri

7 Iteration and families Name: 2 - Verdana

 

Total Number of fonts added in the PrivateFontCollection: 2

8 Iteration and families Name: 0 - Calibri

8 Iteration and families Name: 1 - Verdana

 

Total Number of fonts added in the PrivateFontCollection: 2

9 Iteration and families Name: 0 - Arial

9 Iteration and families Name: 1 - Calibri

 

 

Expected output:

Total Number of fonts added in the PrivateFontCollection: 3

0 Iteration and families Name: 0 - Arial

0 Iteration and families Name: 1 - Calibri

0 Iteration and families Name: 2 - Verdana

 

Total Number of fonts added in the PrivateFontCollection: 3

1 Iteration and families Name: 0 - Arial

1 Iteration and families Name: 1 - Calibri

1 Iteration and families Name: 2 - Verdana

 

Total Number of fonts added in the PrivateFontCollection: 3

2 Iteration and families Name: 0 - Arial

2 Iteration and families Name: 1 - Calibri

2 Iteration and families Name: 2 - Verdana

 

Total Number of fonts added in the PrivateFontCollection: 3

3 Iteration and families Name: 0 - Arial

3 Iteration and families Name: 1 - Calibri

3 Iteration and families Name: 2 - Verdana

 

Total Number of fonts added in the PrivateFontCollection: 3

4 Iteration and families Name: 0 - Arial

4 Iteration and families Name: 1 - Calibri

4 Iteration and families Name: 2 - Verdana

 

Total Number of fonts added in the PrivateFontCollection: 3

5 Iteration and families Name: 0 - Arial

5 Iteration and families Name: 1 - Calibri

5 Iteration and families Name: 2 - Verdana

 

Total Number of fonts added in the PrivateFontCollection: 3

6 Iteration and families Name: 0 - Arial

6 Iteration and families Name: 1 - Calibri

6 Iteration and families Name: 2 - Verdana

 

Total Number of fonts added in the PrivateFontCollection: 3

7 Iteration and families Name: 0 - Arial

7 Iteration and families Name: 1 - Calibri

7 Iteration and families Name: 2 - Verdana

 

Total Number of fonts added in the PrivateFontCollection: 3

8 Iteration and families Name: 0 - Arial

8 Iteration and families Name: 1 - Calibri

8 Iteration and families Name: 2 - Verdana

 

Total Number of fonts added in the PrivateFontCollection: 3

9 Iteration and families Name: 0 - Arial

9 Iteration and families Name: 1 - Calibri

9 Iteration and families Name: 2 - Verdana

 

 

Answer 1

Please provide me with a solution to have a consistent output using PrivateFontCollection.

This works for me with AddFontFile :

                string[] fontList = new string[] { @"arial.ttf", @"calibri.ttf", @"verdana.ttf" };
                PrivateFontCollection fontCollection = null;
                for (int i = 0; i < 10; i++)
                {
                    fontCollection = new PrivateFontCollection();
                    foreach (string fontFile in fontList)
                    {
                        if (!File.Exists(fontFile)) continue;
                        fontCollection.AddFontFile(fontFile);
                    }
                    Console.WriteLine("Total Number of fonts added in the PrivateFontCollection: " + fontCollection.Families.Length);
                    for (int k = 0; k < fontCollection.Families.Length; k++)
                        Console.WriteLine(i.ToString() + " Iteration and families Name: " + k + " - " + fontCollection.Families[k].Name);
                    fontCollection.Dispose();
                    fontCollection = null;
                } 

Answer 2

Hi @Anonymous ,
I apologize for the delay in responding. Thank you for the update.
We should not dispose the font collection for each iteration. If we do not, there could be a memory spike or the memory usage could increase.
Our requirement is not to hold the font collection in the list(mylist.Add(fontCollection).
We need to add fontstream data to the fontCollection instead of using AddFontFile.
So, it is possible to resolve the problem using the GDI+?