---
id: "E:cAlgo.API.ChartArea.ObjectsSelectionChanged"
kind: "event"
type: "T:cAlgo.API.ChartArea"
url: "https://help.ctrader.com/ctrader-algo/references/Chart/ChartArea/ObjectsSelectionChanged/"
---

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

# ChartArea.ObjectsSelectionChanged

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

## ObjectsSelectionChanged

Occurs when chart objects are selected or deselected.

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

- CLI: Never raised: chart objects cannot be selected.
- Cloud: Never raised: chart objects cannot be selected.

C#:

```csharp
event Action<ChartObjectsSelectionChangedEventArgs> ObjectsSelectionChanged;
```

Python:

```python
chartArea.ObjectsSelectionChanged += handler  # handler(obj: ChartObjectsSelectionChangedEventArgs)
```

### Returns

`Action<ChartObjectsSelectionChangedEventArgs>` — 

### Examples

C#:

```csharp
protected override void OnStart()
{
    Chart.ObjectsSelectionChanged += OnObjectsSelectionChanged;
}

private void OnObjectsSelectionChanged(ChartObjectsSelectionChangedEventArgs args)
{
    Print("Selected: {0} | Deselected: {1}", args.ObjectsAddedToSelection.Count, args.ObjectsRemovedFromSelection.Count);
}
```

Python:

```python
def on_start(self):
    api.Chart.ObjectsSelectionChanged += self.on_objects_selection_changed

def on_objects_selection_changed(self, args):
    api.Print(f"Selected: {args.ObjectsAddedToSelection.Count} | Deselected: {args.ObjectsRemovedFromSelection.Count}")
```