在将图像保存到文件夹之前调整图像大小 c# ASP.NET

Question

我正在尝试调整将通过文件输入上传的图像的大小，然后再将其保存到定向文件夹。我尝试了很多可能的方法，但我仍然无法得到它。请帮帮我！

查看

@using (Html.BeginForm("UploadFile", "Upload", FormMethod.Post, new { enctype = "multipart/form-data" }))
{ 
     <input type="file" name="file" id="btnFileUpload" class="zone" runat="server"/>
}

Ajax

$('#btnFileUpload').fileupload({
                    url: '@Url.Action("UploadFile")',
                    dataType: 'json',
                    disableImageResize: /Android(?!.*Chrome)|Opera/
                        .test(window.navigator && navigator.userAgent),
},
            success: function (e, data) {
                //window.location.reload();
                console.log("Done");
                console.log(e);
});

控制器

[HttpPost]  
        public ActionResult UploadFile(HttpPostedFileBase file)  
        {
            string _FileName = "";
            string _path = "";
         try  
            {
               if (file.ContentLength > 0)  
                {
                    _FileName = Path.GetFileName(DateTime.Now.ToBinary() + "-" + file.FileName);
                    _path = Path.Combine(Server.MapPath("~/UploadedFiles"), _FileName);

                    file.SaveAs(_path);


                    imageUrls = "/UploadedFiles/" + _FileName;
                }
                System.Diagnostics.Debug.WriteLine("File Uploaded Successfully!!");

                return Json(imageUrls);
            }  
            catch
            {
                ViewBag.Message = "File upload failed!!";
                System.Diagnostics.Debug.WriteLine("File upload failed!!");
                return Json(ViewBag.Message);  
            }  
        }

Answer 1

这个任务有很多很棒的库可以处理你需要的一切。

我个人使用ImageProcessor。而且我知道还有更多质量相同甚至更好的产品。如果你想要我可以帮你使用它，但是文档应该足够了。

--编辑--

这是使用 ImageProcessor 的示例代码，看看是否有帮助：

var imageFactory = new ImageFactory(true);
imageFactory.Load(inputStream).Resize(
    new ResizeLayer(new Size(128, 128), ResizeMode.Max)).
    Save(path);

另外不要忘记安装所需的 nuget 包:)

Answer 2

这里是你的场景的实现

我认为这会起作用

[HttpPost]
        public ActionResult UploadFile (HttpPostedFileBase file) {

            string _FileName = "";
            string _path = "";
            try {
                if (file.ContentLength > 0) {
                    _FileName = Path.GetFileName (DateTime.Now.ToBinary () + "-" + file.FileName);
                    _path = Path.Combine (Server.MapPath ("~/UploadedFiles"), _FileName);
                    byte[] fileData = null;
                    using (var binaryReader = new BinaryReader (file.InputStream)) {
                        fileData = binaryReader.ReadBytes (file.ContentLength);
                    }

                    HandleImageUpload (fileData, _path);

                    imageUrls = "/UploadedFiles/" + _FileName;
                }
                System.Diagnostics.Debug.WriteLine ("File Uploaded Successfully!!");

                return Json (imageUrls);
            } catch {
                ViewBag.Message = "File upload failed!!";
                System.Diagnostics.Debug.WriteLine ("File upload failed!!");
                return Json (ViewBag.Message);
            }
        }

        private Image RezizeImage (Image img, int maxWidth, int maxHeight) {
            if (img.Height < maxHeight && img.Width < maxWidth) return img;
            using (img) {
                Double xRatio = (double) img.Width / maxWidth;
                Double yRatio = (double) img.Height / maxHeight;
                Double ratio = Math.Max (xRatio, yRatio);
                int nnx = (int) Math.Floor (img.Width / ratio);
                int nny = (int) Math.Floor (img.Height / ratio);
                Bitmap cpy = new Bitmap (nnx, nny, PixelFormat.Format32bppArgb);
                using (Graphics gr = Graphics.FromImage (cpy)) {
                    gr.Clear (Color.Transparent);

                    // This is said to give best quality when resizing images
                    gr.InterpolationMode = InterpolationMode.HighQualityBicubic;

                    gr.DrawImage (img,
                        new Rectangle (0, 0, nnx, nny),
                        new Rectangle (0, 0, img.Width, img.Height),
                        GraphicsUnit.Pixel);
                }
                return cpy;
            }

        }

        private MemoryStream BytearrayToStream (byte[] arr) {
            return new MemoryStream (arr, 0, arr.Length);
        }

        private void HandleImageUpload (byte[] binaryImage, string path) {
            Image img = RezizeImage (Image.FromStream (BytearrayToStream (binaryImage)), 103, 32);
            img.Save (path, System.Drawing.Imaging.ImageFormat.jpg);
        }

resize 代码取自此thread

在将图像保存到文件夹之前调整图像大小 c# ASP.NET

Resize image before saving it to folder c# ASP.NET

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asp.net-ajax