BlueImp jQuery File Upload對縮略圖的預覽改進

Question

我只是將基本的UI示例集成到一個應用程序中。 我要實現的是為某些無法在預覽中呈現的文件添加特定的縮略圖。 例如，我想為word，excel，ppt和pdfs添加一些圖像。 我想獲取固定圖像。

我知道如何生成此文件的預覽，但是首先我想嘗試一些簡單的方法。

我正在檢查此問題Blueimp Jquery File Upload：不顯示縮略圖預覽圖像

就我而言，該控件可以正確預覽視頻和圖像。

他們談論在jquery.fileupload-ui.js中修改此功能

 _renderPreviews: function (data) {
            data.context.find('.preview').each(function (index, elm) {
                $(elm).append(data.files[index].preview);
            });
        },

那是我必須修改才能使它起作用的唯一部分？

如果有人可以向我解釋，控件的內部流程如何生成圖像預覽。 我會很感激的。

Answer 1

最后，我無法在控件中修改預覽功能。

但是，在完成后上傳的項目的第二次渲染中，我實現了一些自定義。 看起來比以前更好。 為了實現這一目標，我修改了

public ActionResult GetThumbnailFile(string folderServerPath,string name, bool thumbnail = false)
        {
            var file = GetFile(name, folderServerPath);
            var contentType = MimeMapping.GetMimeMapping(file.Name);
            return thumbnail ? Thumb(file, contentType) : File(file.FullName, contentType);
        }

        private ActionResult Thumb(FileInfo file, string contentType)
        {
            if (contentType.StartsWith("image"))
            {
                try
                {
                    using (var img = Image.FromFile(file.FullName))
                    {
                        var thumbHeight = (int)(img.Height * (ThumbSize / (double)img.Width));
                        using (var thumb = img.GetThumbnailImage(ThumbSize, thumbHeight, () => false, IntPtr.Zero))
                        {
                            var ms = new MemoryStream();
                            thumb.Save(ms, img.RawFormat);
                            ms.Position = 0;
                            return File(ms, contentType);
                        }
                    }
                }
                catch (Exception ex)
                {
                    // todo log exception
                }
            }
            else
            {
                switch (file.Extension.ToUpperInvariant())
                {
                    case ".LOG":
                        return File("~/Images/general_documents_preview/txt-icon-128.png", contentType);
                    case ".PDF":
                        return File("~/Images/general_documents_preview/pdf-icon-128.png", contentType);
                    case "JPEG":
                        //icon = "JPEG-File-icon-128.png";
                        break;
                    case "JPG":
                        //icon = "JPEG-File-icon-128.png";
                        break;
                    case "WBMP":
                        //icon = "Illustrator-File-icon128.png";
                        break;
                    case "BMP":
                        //icon = "BMP-File-icon-128.png";
                        break;
                    case "TIF":
                        //icon = "Web-File-icon-128.png";
                        break;
                    case "JP2":
                        //icon = "Vector-File-icon-128.png";
                        break;
                    case "JBIG2":
                        //icon = "Vector-File-icon-128.png";
                        break;
                    case "EMF":
                        //icon = "Photoshop-File-icon-128.png";
                        break;
                    case "GIF":
                        //icon = "GIF-File-icon-128.png";
                        break;
                    case "PNG":
                        //icon = "PNG-File-icon-128.png";
                        break;
                    case "TXT":
                        return File("~/Images/general_documents_preview/txt-icon-128.png", contentType);
                    case ".DOC":
                        return File("~/Images/general_documents_preview/doc-icon-128.png", contentType);
                    //icon = "doc-icon-128.png";
                    case ".DOCX":
                        return File("~/Images/general_documents_preview/docx-icon-128.png", contentType);
                    //icon = "docx-icon-128.png";
                    case ".PST":
                        return File("~/Images/general_documents_preview/pst-icon-128.png", contentType);
                    //icon = "pst-icon-128.png";
                    case ".PPT":
                        return File("~/Images/general_documents_preview/ppt-icon-128.png", contentType);
                    //icon = "ppt-icon-128.png";
                    case ".PPTX":
                        return File("~/Images/general_documents_preview/pptx-icon-128.png", contentType);
                    //icon = "pptx-icon-128.png";
                    case ".HTML":
                        return File("~/Images/general_documents_preview/html-icon-128.png", contentType);
                    //icon = "html-icon-128.png";
                    case ".RTF":
                        return File("~/Images/general_documents_preview/rtf-icon-128.png", contentType);
                    //icon = "rtf-icon-128.png";
                    case ".DLL":
                        return File("~/Images/general_documents_preview/dll-icon-128.png", contentType);
                    //icon = "dll-icon-128.png";
                    case "EML":
                        //icon = "eml-icon-128.png";
                        break;
                    case ".FLA":
                        return File("~/Images/general_documents_preview/fla-icon-128.png", contentType);
                    case ".SWF":
                        return File("~/Images/general_documents_preview/fla-icon-128.png", contentType);
                    //icon = "fla-icon-128.png";
                    case ".MP3":
                        return File("~/Images/general_documents_preview/mp3-icon-128.png", contentType);
                    case ".XLS":
                        return File("~/Images/general_documents_preview/xls-icon-128.png", contentType);
                    //icon = "xls-icon-128.png";
                    case ".XLSX":
                        return File("~/Images/general_documents_preview/xlsx-icon-128.png", contentType);
                    //icon = "xlsx-icon-128.png";
                    default://unknow
                        return File("~/Images/general_documents_preview/bin-icon-128.png", contentType);

                }

            }

            return Redirect($"https://placehold.it/{ThumbSize}?text={Url.Encode(file.Extension)}");
        }

您可以從https://github.com/ronnieoverby/blue-imp-upload-aspnet-mvc/tree/master/src/jquploadz下載原始示例項目來檢查更改

Answer 2

這是我的解決方法，用於在文件上傳后添加自定義縮略圖，假設您使用的是演示示例中的blueimp javascript模板（x-tmpl）： https : //github.com/blueimp/JavaScript-Templates

<span class="preview">
            {% if (file.thumbnailUrl) { %}
                <a href="{%=file.url%}" title="{%=file.name%}" download="{%=file.name%}" data-gallery><img src="{%=file.thumbnailUrl%}"></a>
            {% } else {

            // Display relevant icon
            var ext = file.name.substr(file.name.lastIndexOf('.') + 1);
            var icon = "icons/generic.png";

            if (ext === "pdf") {var icon="icons/pdf.png"};
            if (ext === "xls" || ext === "xlsx" || ext === "csv" || ext === "ods" || ext === "xlr") {var icon="icons/excel.png"};
            if (ext === "psd" || ext === "psb" || ext === "eps" || ext === "tif" || ext === "tiff" || ext === "indd"  || ext === "ind" || ext === "bmp" || ext === "ai") {var icon="icons/graphic.png"};
            if (ext === "tar" || ext === "rar" || ext === "tgz"  || ext === "gz" || ext === "7z" || ext === "sit" || ext === "sitx" || ext === "cab") {var icon="icons/archive.png"};
            if (ext === "docx" || ext ==="doc") {var icon="icons/word.png"};
            if (ext === "rtf" || ext === "txt" || ext === "log" || ext === "xml" || ext === "css" || ext === "htm" || ext === "html") {var icon="icons/txt.png"};
            if (ext === "zip") {var icon="icons/zip.png"};
            if (ext === "mov" || ext === "avi" || ext === "m4v" || ext === "3gp" || ext === "mpeg" || ext === "mkv"  || ext === "vob" || ext === "aaf" || ext === "asf" || ext === "wmv" || ext === "flv" || ext === "swf" || ext === "mpg" || ext === "mp4") {var icon="icons/mov.png"};
            if (ext === "ppt" || ext === "pptx" || ext === "pps") {var icon="icons/ppt.png"};
            if (ext === "pkg" || ext === "rpm") {var icon="icons/pkg.png"};
            if (ext === "dmg" || ext === "iso" || ext === "bin" || ext === "toast") {var icon="icons/dmg.png"};
            if (ext === "key" || ext === "odp") {var icon="icons/keynote.png"};
            if (ext === "pages" || ext === "odt") {var icon="icons/pages.png"};
            if (ext === "numbers") {var icon="icons/numbers.png"};
            if (ext === "wav" || ext === "aif" || ext === "aiff" || ext === "m4a" || ext === "ogg" || ext === "mp3" || ext === "caf" || ext === "aac") {var icon="icons/wav.png"};
            if (ext === "fnt" || ext === "fon" || ext === "otf" || ext === "ttf") {var icon="icons/font.png"};

            %}<img src="{%=icon%}">{% } %}


        </span>