---
title: "TiffExtraChannelCollection..::.IndexOf Method "
canonical: https://www.graphicsmill.com/docs/gm5/M_Aurigma_GraphicsMill_Codecs_TiffExtraChannelCollection_IndexOf_1_3cf9a70f.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/)

# TiffExtraChannelCollection.IndexOf Method 
 
Searches for the specified extra channel and returns the zero-based index of the first occurrence within the entire collection.
 
**Namespace:** [Aurigma.GraphicsMill.Codecs](https://www.graphicsmill.com/docs/gm5/N_Aurigma_GraphicsMill_Codecs.htm.md)
 **Assembly:** Aurigma.GraphicsMill (in Aurigma.GraphicsMill.dll)
 
## Syntax
  
```
Public Function IndexOf ( _item As TiffExtraChannel _
) As Integer
```
 
```csharp
public int IndexOf(TiffExtraChannel item
)
```
 
### Parameters
 
 - item
     - Type: [Aurigma.GraphicsMill.Codecs.TiffExtraChannel](https://www.graphicsmill.com/docs/gm5/T_Aurigma_GraphicsMill_Codecs_TiffExtraChannel.htm.md)
The extra channel to locate in the collection.
 
### Return Value
A zero-based index of the first occurrence of the extra channel within the entire collection, if found; otherwise, -1.
   
## See Also

### Reference

- [TiffExtraChannelCollection Class](https://www.graphicsmill.com/docs/gm5/T_Aurigma_GraphicsMill_Codecs_TiffExtraChannelCollection.htm.md)
- [Aurigma.GraphicsMill.Codecs Namespace](https://www.graphicsmill.com/docs/gm5/N_Aurigma_GraphicsMill_Codecs.htm.md)