Golang反射获取函数签名技巧

package main

import (
    "fmt"
    "reflect"
)

func example(a int, b string) (bool, error) {
    return true, nil
}

func main() {
    fn := reflect.TypeOf(example)
    fmt.Println("函数名称：", fn.Name()) // 输出：example
    fmt.Println("参数数量：", fn.NumIn())
    fmt.Println("返回值数量：", fn.NumOut())
}

<code>// 打印所有参数类型
for i := 0; i < fn.NumIn(); i++ {
    fmt.Printf("参数 %d: %v\n", i, fn.In(i))
}

// 打印所有返回值类型
for i := 0; i < fn.NumOut(); i++ {
    fmt.Printf("返回值 %d: %v\n", i, fn.Out(i))
}
</code>

if fn.Kind() != reflect.Func {
    fmt.Println("不是函数类型")
    return
}

<code>func printSignature(fn interface{}) {
    t := reflect.TypeOf(fn)
    if t.Kind() != reflect.Func {
        fmt.Println("输入不是函数")
        return
    }

    inTypes := make([]string, t.NumIn())
    for i := 0; i < t.NumIn(); i++ {
        inTypes[i] = t.In(i).String()
    }

    outTypes := make([]string, t.NumOut())
    for i := 0; i < t.NumOut(); i++ {
        outTypes[i] = t.Out(i).String()
    }

    fmt.Printf("func(%s) (%s)\n",
        joinStrings(inTypes, ", "),
        joinStrings(outTypes, ", "))
}

func joinStrings(parts []string, sep string) string {
    if len(parts) == 0 {
        return ""
    }
    result := parts[0]
    for i := 1; i < len(parts); i++ {
        result += sep + parts[i]
    }
    return result
}
</code>