Golang 将 Base64 格式图片上传并保存到本地文件夹

以下是将 Base64 格式图片上传并保存到本地文件夹的 Golang 代码示例：

package main

import (
    "encoding/base64"
    "io/ioutil"
    "os"
)

func main() {
    base64Str := 'data:image/png;base64,iVBORw0KGgoAAAANSUhEUgAAAEAAAABACAYAAACqaXHeAAAABmJLR0QA/wD/AP+gvaeTAAADZklEQVR4nO3dQY7jOQCG4QdH7B9KjgKtIYpZM1JY7jKtIYpZM1JY7jKtIYpZM1JY7jKtIYpZM1JY7jKtIYpZM1JY7jKtIYpZM1JY7jKtIYpZM1JY7jKtIYpZM1JY7jKtIYpZM1JY7jKtIYpZM1JY7jKtIYpZM1JY7jKtIYpZM1JY7jKtIYpZM1JY7jKtIYpZM1JY7jKtIYpZM1JY7jKtIYpZM1JY7jKtIYpZM1JY7jKtIYpZM1JY7jKtIYpZM1JY7jKtIYpZM1JY7jKtIYpZM1JY7jKtIYpZM1JY7jKtIYpZM1JY7jKtIYpZM1JY7jKtIYpZM1JY7jKtIYpZM1JY7jKtIYpZM1JY7jKtIYpZM1JY7jKtIYpZM1JY7jKtIYpZM1JY7jKtIYr2JPs7MgKzGAAAAAElFTkSuQmCC'
    data, err := base64.StdEncoding.DecodeString(base64Str[22:])
    if err != nil {
        panic(err)
    }
    err = ioutil.WriteFile("path/to/save/image.png", data, 0644)
    if err != nil {
        panic(err)
    }
}

在上面的示例中，我们使用了 encoding/base64 和 io/ioutil 包来解码 Base64 字符串和将二进制数据写入本地文件。首先，我们需要将 Base64 格式的字符串去除 data URL 的前缀，并使用 base64.StdEncoding.DecodeString() 函数解码得到二进制数据。然后，我们使用 ioutil.WriteFile() 函数将二进制数据写入指定路径的文件中。如果出现任何错误，我们将会抛出 panic 异常。