在图像查看器中显示图像-HTML5 JavaScript

window.onload =功能（）{varClaneurl =“ ./leadtools/leadtools.lic.txt”;vardeveloperKey =“替换_WITH_KEY_CONTENTS”;lt.rastersupport.setlicenseuri（plineerkey，developerkey，功能（（setlicenseresult）{//检查许可证状态如果（setlicenseresult.result）{console.log（“ LeadTools客户许可成功设置”）；}别的{varmsg =“缺少LeadTools许可证，无效或过期的\ nerror：\ n”;console.log（msg）;警报（msg）;}}）;//在ImageViewerDiv元素中创建图像查看器constimageViewerDiv = document.getElementById（“ ImageViewerDiv”）；constcreateOptions =新的lt.controls.imageViewerCreateoptions（ImageViewerDiv）；这个.imageViewer =新的lt.controls.imageviewer（createOptions）;这个.imageViewer.ViewVerticalAlignment = lt.controls.controlalailignment.center;这个.imageViewer.ViewHorizo​​ntalAlagign =lt.controls.controlalagignment.center;这个.imageViewer.AutocreateCanvas =真的;//添加pan/Zoom Interactive模式//单击并拖动锅，ctrl-click并拖动以放大进出这个.imageViewer.InteractiveModes.Add（新的lt.controls.imageviewerpanzoomintractivemode（））；//加载图像这个.imageViewer.imageUrl =“ https://demo.leadtools.com/images/jpeg/cannon.jpg”;这个.imageViewer.Zoom（lt.controls.controlsizemode.fit，0.9，这个.imageViewer.defaultZoomorigin）；//输入文件constfileInput = document.getElementById（“ fileintut”）；fileInput.AddeventListener（“改变”，（event）=> {//将查看器映像的URL更改为输入文件。如果（event.target.files [0]！=无效的）这个.imageViewer.imageurl = url.createobjectUrl（event.target.files [0]）;}）;//下载功能constdownloadbutton = document.getElementById（“下载丁顿”）；downloadbutton.addeventlistener（“点击”，（）=> {var图像=新的图片（）;Image.Crossorigin =“匿名的”;image.src =这个.imageViewer.imageurl;document.body.append（image）;image.onload =（）=> {varcanvas = document.createelement（“帆布”）；canvas.width = image.width;canvas.height = image.height;canvas.getContext（“ 2D”）.drawImage（图像，0，0）;var斑点blob = canvas.todataurl（“图像/jpeg”）；vara = document.createelement（“一个”）；a.href = blob;A.下载=“ output.png”;document.body.appendchild（a）;A.Click（）;document.body.removechild（a）;};document.body.removechild（image）;}）;};