ViewToken Object Type
ViewToken object is returned as one of the properties in the onViewableItemsChanged callback (for example, in the FlatList component). It is exported by ViewabilityHelper.js.
Example
JavaScript
{
item: {key: "key-12"},
key: "key-12",
index: 11,
isViewable: true
}
Keys and values
index
Unique numeric identifier assigned to the data element.
当可视元素不是数据数组中的数据项时，此属性可能为 null\)，例如 [SectionList`](sectionlist) 的分区标题或分区页脚进入可视区域时。
| Type | Optional |
|---|---|
| number | Yes |
isViewable
Specifies if at least some part of list element is visible in the viewport.
| Type | Optional |
|---|---|
| boolean | No |
item
Item data
| Type | Optional |
|---|---|
| any | No |
key
Key identifier assigned to the data element extracted to the top level.
| Type | Optional |
|---|---|
| string | No |
section
Item section data when used with SectionList.
| Type | Optional |
|---|---|
| any | Yes |