# Sandbox.UI.PanelRenderTreeBuilder.OpenElement

## Overload 1

```csharp
void OpenElement(int sequence, string elementName)
```

### Parameters

- `sequence` (`int`)
- `elementName` (`string`)

## Overload 2

```csharp
void OpenElement(int sequence, string elementName, object key = null)
```

Start working on this element

### Parameters

- `sequence` (`int`)
- `elementName` (`string`)
- `key` (`object`), default `null`

## Overload 3

```csharp
void OpenElement(int sequence)
```

### Parameters

- `sequence` (`int`)

## Overload 4

```csharp
void OpenElement(int sequence, object key)
```

Create a panel of type T

### Parameters

- `sequence` (`int`)
- `key` (`object`)

Declared in [Sandbox.UI.PanelRenderTreeBuilder](/api/Sandbox.UI.PanelRenderTreeBuilder).
Assembly: `Sandbox.Engine`.