每项高度有个计算值，不知道是从哪里计算的，然后在IPAD下高度太小，显示不出。

```

<View className='w-picker-view'>

<PickerView className="d-picker-view" indicatorStyle={this.props.itemHeight} value={pickVal} onChange={this.handlerChange} onPickStart={this.props.touchstart} onPickEnd={this.props.touchend}>

<PickerViewColumn>

{

this.range().map((item, index) => {

return (<View className="w-picker-item" key={index}>{item[this.nodeKey()]}</View>)

})

}

</PickerViewColumn>

</PickerView>

</View>

```