我有一个自定义时间格式,我用它来正确编码/解码json。但是每当我需要进行时间计算时,我都需要进行演员表演。这是正确的方法吗?继续铸造感觉有点难看。例如,当我需要“更新”我需要投射两次的值(一次到一次,一次到我的类型)
type Mytime time.Time
var t Mytime
t = Mytime(time.Now())
// Add an hour to my typed time
t = Mytime(time.Time(t).Add(1 * time.Hour))
答案 0 :(得分:2)
据推测,你有type Mytime time.Time
。相反,如果你嵌入它:
type MyTime struct {
time.Time
}
然后你可以:
func (t MyTime) MarshalJSON() ([]byte, error) {
… whatever …
}
仍然可以访问所有time.Time
的方法。
例如。类似的东西:
t := MyType{time.Now()}
t.Time = t.Add(time.Hour)
富勒示例显示嵌入式和非嵌入式自定义时间类型之间的差异。请注意,嵌入仍然不允许与期望time.Time
值的事物透明地互用。 (这里省略了制作这些类型的原因,例如添加MarshalJSON
方法。)
package main
import (
"fmt"
"time"
)
type YourTime time.Time
type MyTime struct{ time.Time }
// Some random functions, perhaps in a third party package,
// that deals with time.Time values.
func fn(t time.Time) {
fmt.Println("fn got:", t)
}
func fn2() time.Time {
return time.Unix(14e8, 0)
}
func main() {
var t1 = YourTime(time.Now())
//t1 = t1.Add(time.Hour) // compiler error
t1 = YourTime(time.Time(t1).Add(time.Hour))
fmt.Println("ugly t1:", t1)
fmt.Println("nice t1:", time.Time(t1))
//fn(t1) // compiler error
fn(time.Time(t1))
//t1 = fn2() // compiler error
t1 = YourTime(fn2())
var t2 = MyTime{time.Now()}
// t2 = t2.Add(time.Hour) // compiler error
t2.Time = t2.Add(time.Hour)
fmt.Println("t2:", t2)
//fn(t2) // compiler error
fn(t2.Time)
//t2 = fn2() // compiler error
t2.Time = fn2()
}
输出:
ugly t1: {63393494400 0 0x1c9340}
nice t1: 2009-11-11 00:00:00 +0000 UTC
fn got: 2009-11-11 00:00:00 +0000 UTC
t2: 2009-11-10 23:00:00 +0000 UTC
fn got: 2009-11-10 23:00:00 +0000 UTC