vant 只显示年份

https://blog.csdn.net/qq_42859450/article/details/111874107

修改代码源码路径：node_modules / vant / es / datetime-picker / DatePicker.js
1、 case 'year':
result = result.slice(0, 1);
break;

2、 month = type === 'year' ? 1 : getValue('month');