废话不多说直接上代码：

package utils

import (
    "bytes"
    "crypto/rand"
    "math/big"
)

func CreateRandomString(len int) string {
    var container string
    var str = "abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ1234567890"
    b := bytes.NewBufferString(str)
    length := b.Len()
    bigInt := big.NewInt(int64(length))
    for i := 0; i < len; i++ {
        randomInt, _ := rand.Int(rand.Reader, bigInt)
        container += string(str[randomInt.Int64()])
    }
    return container
}