## 基础使用

让一个按钮一直处于可视范围内

```json
{
    "body": [{
        "type": "container",
        "model": "affixContainer",
        "children": [{
            "type": "affix",
            "trigger": [{
                "event": "onChange",
                "targetCustomer": "$this",
                "params": {
                    "affixed": "#ES{$args.affixed}"
                }
            }],
            "offsetTop": 100,
            "style": {
                "width": "100%"
            },
            "children": [{
                "type": "button",
                "text": "Affix status: #ES{$data.affixed}"
            }]
        }]
    }]
}
```