---
title: "tableView(_:mouseDownInHeaderOf:)"
framework: appkit
role: symbol
role_heading: Instance Method
path: "appkit/nstableviewdelegate/tableview(_:mousedowninheaderof:)"
---

# tableView(_:mouseDownInHeaderOf:)

Tells the delegate that the mouse button was clicked in the specified table column’s header.

## Declaration

```swift
@MainActor optional func tableView(_ tableView: NSTableView, mouseDownInHeaderOf tableColumn: NSTableColumn)
```

## Parameters

- `tableView`: The table view that sent the message.
- `tableColumn`: The table column.

## See Also

### Responding to mouse events

- [tableView(_:didClick:)](appkit/nstableviewdelegate/tableview(_:didclick:).md)
- [tableView(_:shouldTrackCell:for:row:)](appkit/nstableviewdelegate/tableview(_:shouldtrackcell:for:row:).md)