Bagaimana untuk mengkonfigurasi had saiz muat naik fail dalam projek Golang?

package main

import (
    "fmt"
    "log"
    "net/http"
    "os"
)

func main() {
    // 设置上传文件大小限制为 10 MB
    maxFileSize := int64(10 * 1024 * 1024)

    // 创建文件上传处理程序
    http.HandleFunc("/upload", func(w http.ResponseWriter, r *http.Request) {
        // 检查请求是否是多部分表单
        if r.Method == "POST" && r.MultipartForm == nil {
            http.Error(w, "请求不是多部分表单", http.StatusBadRequest)
            return
        }

        // 解析多部分表单
        if err := r.ParseMultipartForm(maxFileSize); err != nil {
            http.Error(w, fmt.Sprintf("解析表单时出错：%v", err), http.StatusInternalServerError)
            return
        }

        // 提取上传文件
        file, fileHeader, err := r.FormFile("file")
        if err != nil {
            http.Error(w, fmt.Sprintf("提取文件时出错：%v", err), http.StatusBadRequest)
            return
        }
        defer file.Close()

        // 将文件保存到磁盘
        dst, err := os.Create("uploaded_file")
        if err != nil {
            http.Error(w, fmt.Sprintf("保存文件时出错：%v", err), http.StatusInternalServerError)
            return
        }
        defer dst.Close()

        if _, err = io.Copy(dst, file); err != nil {
            http.Error(w, fmt.Sprintf("复制文件时出错：%v", err), http.StatusInternalServerError)
            return
        }

        // 返回成功响应
        fmt.Fprintf(w, "文件上传成功！")
    })

    // 启动服务器
    log.Fatal(http.ListenAndServe(":8080", nil))
}

{
    "error": "文件大小超出了限制"
}