---
id: "E:cAlgo.API.TabControl.SelectedTabChanged"
kind: "event"
type: "T:cAlgo.API.TabControl"
url: "https://help.ctrader.com/ctrader-algo/references/Controls/TabControl/SelectedTabChanged/"
---

> Documentation index for agents: https://help.ctrader.com/ctrader-algo/llms.txt · machine index: https://help.ctrader.com/ctrader-algo/api.json

# TabControl.SelectedTabChanged

Member of [TabControl](https://help.ctrader.com/ctrader-algo/references/Controls/TabControl/index.md).

## SelectedTabChanged

Occurs when the selected tab is changed.

Environments: Desktop supported · CLI not supported · Cloud not supported.

- CLI: Accepted without error but never displayed, so control events such as Click are never raised.
- Cloud: Accepted without error but never displayed, so control events such as Click are never raised.

C#:

```csharp
public event Action<TabControlSelectedTabChangedEventArgs> SelectedTabChanged;
```

Python:

```python
tabControl.SelectedTabChanged += handler  # handler(obj: TabControlSelectedTabChangedEventArgs)
```

### Returns

`Action<TabControlSelectedTabChangedEventArgs>` — 

Available since cAlgo.API 5.2.

### Examples

C#:

```csharp
var tabControl = new TabControl();
tabControl.AddTab(new TabItem { Header = new TextBlock { Text = "Trade" } });
tabControl.AddTab(new TabItem { Header = new TextBlock { Text = "History" } });
tabControl.SelectedTabChanged += args => Print("Selected tab index: {0}", args.TabControl.Tabs.ToList().IndexOf(args.SelectedTab));
Chart.AddControl(tabControl);
```

Python:

```python
def on_start(self):
    tabControl = TabControl()
    for title in ["Trade", "History"]:
        header = TextBlock()
        header.Text = title
        tab = TabItem()
        tab.Header = header
        tabControl.AddTab(tab)
    tabControl.SelectedTabChanged += self.on_selected_tab_changed
    api.Chart.AddControl(tabControl)

def on_selected_tab_changed(self, args):
    api.Print(f"Selected tab header: {args.SelectedTab.Header.Text}")
```