---
title: "CustomFormatReader..::.CheckOpened Method "
canonical: https://www.graphicsmill.com/docs/gm5/M_Aurigma_GraphicsMill_Codecs_CustomFormatReader_CheckOpened.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.CheckOpened Method 
 
Checks if the format reader is opened.
 
**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 Sub CheckOpened
```
 
```csharp
protected internal override void CheckOpened()
```
 
## Remarks
  
This method is called whenever any reader property that is associated with an opened file (for example, dimensions or quality) is used. It is also called when the frame is loaded using the [LoadFrame(Int32)](https://www.graphicsmill.com/docs/gm5/M_Aurigma_GraphicsMill_Codecs_FormatReader_LoadFrame_1_e1836fc4.htm.md) method.
 
No need to implement this method yourself. Use the standard implementation.
   
## 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.Opened](https://www.graphicsmill.com/docs/gm5/P_Aurigma_GraphicsMill_Codecs_FormatReader_Opened.htm.md)
- [FormatReader.LoadFrame(Int32)](https://www.graphicsmill.com/docs/gm5/M_Aurigma_GraphicsMill_Codecs_FormatReader_LoadFrame_1_e1836fc4.htm.md)