工作中偶尔会用到枚举值和 int 的互相转化，今天总结一下；
枚举值转 int：在当前索引值后加 .index 即可（默认从 0 开始）；
int 转枚举值：需要扩展枚举方法实现，实现如下；
定义枚举 PageViewScrollType
/// PageView 滚动方式
enum PageViewScrollType {
/// 整屏滑动
full,
/// 拖拽滑动
drag,
/// 禁用滑动
none,
}
extension PageViewScrollType_IntExt on int{
/// int 转枚举
PageViewScrollType? toPageViewScrollType([bool isClamp = true]){
final allCases = PageViewScrollType.values;
if (!isClamp) {
if (this < 0 || this > allCases.length - 1) {
return null;
}
return allCases[this];
}
final index = this.clamp(0, allCases.length - 1);
return allCases[index];
}
/// int 转枚举
PageViewScrollType get pageViewScrollType{
final allCases = PageViewScrollType.values;
// final index = this.clamp(0, allCases.length - 1);
// return allCases[index];
return this.toPageViewScrollType(true) ?? allCases.first;
}
}
如此就实现了 枚举值和 int的互相转化，打印如下：
print("枚举值索引: ${PageViewScrollType.full.index}");
print("枚举值字符串: ${PageViewScrollType.drag.toString()}");
print("枚举集合: ${PageViewScrollType.values}");
print("int 转枚举: ${0.toPageViewScrollType()}");
//枚举值索引: 0
//枚举值字符串: PageViewScrollType.drag
//枚举集合: [ PageViewScrollType.full, PageViewScrollType.drag, PageViewScrollType.none ]
//int 转枚举: PageViewScrollType.full
