一,安装第三方库
$ go get -u github.com/disintegration/imaging
go: downloading golang.org/x/image v0.0.0-20191009234506-e7c1f5e7dbb8
go: downloading golang.org/x/image v0.31.0
go: added github.com/disintegration/imaging v1.6.2
go: added golang.org/x/image v0.31.0
二,代码:
函数:
//生成缩略图
func MakeThumbImage(orig,thumb string,size int) {//得到图片的宽高fileImg, err := os.Open(orig) // 替换为你的图片文件路径if err != nil {//panic(err)}defer fileImg.Close()img, _, err := image.DecodeConfig(fileImg)if err != nil {//panic(err)}fmt.Printf("Width: %d, Height: %d\n", img.Width, img.Height)//根据大图生成缩略图src, err := imaging.Open(orig)if err != nil {//log.Fatalf("failed to open image: %v", err)}//生成缩略图,使长边始终为指定的长度width:=0height:=0if img.Width>= img.Height {width = sizeheight = 0} else {height = sizewidth = 0}//生成缩略图dsc := imaging.Resize(src, width, height, imaging.Lanczos)//保存缩略图err = imaging.Save(dsc, thumb)
}
controller中调用:
//接收上传,多张图片
func (ic *MediaController) Uploaded(c *gin.Context) {//得到formform,err:=c.MultipartForm()//得到文件列表files:=form.File["f1m"]//错误处理if err != nil {global.NewResult(c).ErrorCode(500,"图片上传失败",nil)return}idStr:=global.FormattedNow("20060102150405");dateStr:=global.FormattedNow("20060102");//原图路径origDir := "./data/ware/"+dateStr//如果目录不存在,则创建它if global.IsDirExists(origDir) == false {// 创建多级目录err := os.MkdirAll(origDir, 0755)if err != nil {fmt.Println(err)}}//预览图路径preDir := "./static/ware/"+dateStr//如果目录不存在,则创建它if global.IsDirExists(preDir) == false {// 创建多级目录err := os.MkdirAll(preDir, 0755)if err != nil {fmt.Println(err)}}//处理文件var images []stringfor i,f:=range files{//fmt.Println(f.Filename)istr := strconv.Itoa(i)//保存为原图origImage := origDir+"/"+idStr+"_"+istr+".jpg"c.SaveUploadedFile(f,origImage)//生成缩略图preImage := preDir+"/"+idStr+"_"+istr+".jpg"global.MakeThumbImage(origImage,preImage,400)//返回预览图的urlimageUrl := "/static/ware/"+dateStr+"/"+idStr+"_"+istr+".jpg"images = append(images, imageUrl)}global.NewResult(c).Success(images)}
三,测试效果:
返回的url是生成的长边为400的缩略图