## IWarningCallback.Warning method

Aspose.Words invokes this method when it encounters some issue during document loading or saving that might result in loss of formatting or data fidelity.

```csharp
public void Warning(WarningInfo info)
```

## Examples

Shows how to set the property for finding the closest match for a missing font from the available font sources.

```csharp
// Open a document that contains text formatted with a font that does not exist in any of our font sources.
Document doc = new Document(MyDir + "Missing font.docx");

// Assign a callback for handling font substitution warnings.
WarningInfoCollection warningCollector = new WarningInfoCollection();
doc.WarningCallback = warningCollector;

// Set a default font name and enable font substitution.
FontSettings fontSettings = new FontSettings();
fontSettings.SubstitutionSettings.DefaultFontSubstitution.DefaultFontName = "Arial";
fontSettings.SubstitutionSettings.FontInfoSubstitution.Enabled = true;

// Original font metrics should be used after font substitution.
doc.LayoutOptions.KeepOriginalFontMetrics = true;

// We will get a font substitution warning if we save a document with a missing font.
doc.FontSettings = fontSettings;
doc.Save(ArtifactsDir + "FontSettings.EnableFontSubstitution.pdf");

foreach (WarningInfo info in warningCollector)
{
    if (info.WarningType == WarningType.FontSubstitution)
        Console.WriteLine(info.Description);
}
```

### See Also

* class [WarningInfo](../../warninginfo/)
* interface [IWarningCallback](../)
* namespace [Aspose.Words](../../../aspose.words/)
* assembly [Aspose.Words](../../../)