---
title: "CustomFormatReader..::.OnCheckForSupport Method "
canonical: https://www.graphicsmill.com/docs/gm5/M_Aurigma_GraphicsMill_Codecs_CustomFormatReader_OnCheckForSupport_1_bca7c9fe.htm
product: "Graphics Mill 5.5 for .NET"
---

This documentation is for the old version. [Go to the latest Graphics Mill docs](https://www.graphicsmill.com/docs/gm/)

# CustomFormatReader.OnCheckForSupport Method 
 
Checks if the codec can read the specified file.
 
**Namespace:** [Aurigma.GraphicsMill.Codecs](https://www.graphicsmill.com/docs/gm5/N_Aurigma_GraphicsMill_Codecs.htm.md)
 **Assembly:** Aurigma.GraphicsMill (in Aurigma.GraphicsMill.dll)
 
## Syntax
  
```
Protected Friend Overrides Function OnCheckForSupport ( _stream As Stream _
) As Boolean
```
 
```csharp
protected internal override bool OnCheckForSupport(Stream stream
)
```
 
### Parameters
 
 - stream
     - Type: [System.IO.Stream](http://msdn2.microsoft.com/en-us/8f86tw9e)
The stream that contains the file to test.
 
### Return Value
 **true**, if the stream can be read by the codec, otherwise **false**.
 
## Remarks
  
This method is called by the [CheckForSupport(Stream)](https://www.graphicsmill.com/docs/gm5/M_Aurigma_GraphicsMill_Codecs_FormatReader_CheckForSupport_1_bca7c9fe.htm.md) method and has a standard implementation that calls the [IsSupported(Stream)](https://www.graphicsmill.com/docs/gm5/M_Aurigma_GraphicsMill_Codecs_CustomFormatReader_IsSupported_1_bca7c9fe.htm.md) method.
 
**Note** 
No need to implement this method directly. Implement the [IsSupported(Stream)](https://www.graphicsmill.com/docs/gm5/M_Aurigma_GraphicsMill_Codecs_CustomFormatReader_IsSupported_1_bca7c9fe.htm.md) method instead.
   
## See Also

### Reference

- [CustomFormatReader Class](https://www.graphicsmill.com/docs/gm5/T_Aurigma_GraphicsMill_Codecs_CustomFormatReader.htm.md)
- [Aurigma.GraphicsMill.Codecs Namespace](https://www.graphicsmill.com/docs/gm5/N_Aurigma_GraphicsMill_Codecs.htm.md)
- [FormatReader.CheckForSupport(Stream)](https://www.graphicsmill.com/docs/gm5/M_Aurigma_GraphicsMill_Codecs_FormatReader_CheckForSupport_1_bca7c9fe.htm.md)
- [FormatReader.CheckForSupport(String)](https://www.graphicsmill.com/docs/gm5/M_Aurigma_GraphicsMill_Codecs_FormatReader_CheckForSupport_1_bb3a7a4f.htm.md)
- [CustomFormatReader.IsSupported(Stream)](https://www.graphicsmill.com/docs/gm5/M_Aurigma_GraphicsMill_Codecs_CustomFormatReader_IsSupported_1_bca7c9fe.htm.md)