Web扫描识别控件Dynamic Web TWAIN使用实例:上传和扫描
Dynamic Web TWAIN是一个专为Web应用程序设计的TWAIN扫描识别控件,允许用户从扫描仪扫描文档或从数码相机/采集卡中获取图像,并支持上传和处理本地图像。本文将介绍如何通过TWAIN扫描识别工具Dynamic Web TWAIN实现在Web应用程序中扫描和上传文件。
下载并安装Dynamic Web TWAIN后, 在 "\Dynamsoft\Dynamic Web TWAIN 9.0 Trial\Resources."目录下找到下列文件:
- DynamicWebTWAIN.cab/ DynamicWebTWAINx64.cab – the ActiveX control edition for Internet Explorer (IE) 32 bit and 64 bit
- DynamicWebTWAINPlugIn.msi - the Plugin Edition for Chrome, Firefox, Safari on Windows
- DynamicWebTWAINMacEditionTrial.pkg – the Mac Edition for Chrome, Firefox, Safari on Mac OS X
将上述提到4个Dynamic Web TWAIN 插件文件复制并粘贴到MVC应用程序的Content文件夹中,从而将TWAIN扫描识别控件Dynamic Web TWAIN 嵌入到MVC应用程序。
Dynamic Web TWAIN文档扫描视图
如下面的截图所示,索引页上已添加了一个"Scan" 选项卡。点击 "Scan",用户将看到使用了Dynamic Web TWAIN插件的Scan.aspx页面。
启动Dynamic Web TWAIN
function DW_CreateControl(bNeebBack) { var objString = ""; var DWTContainer; // For IE, render the ActiveX Object if (DW_InIE) { objString = "<object id='" + DW_ObjectName + "' style='width:" + DW_Width + "px;height:" + DW_Height + "px'"; if (DW_InWindowsX86) objString += "codebase='" + DW_CABX86Path + "#version=" + DW_VersionCode + "' "; //load 32 bit CAB file for 32 bit Windows else objString += "codebase='" + DW_CABX64Path + "#version=" + DW_VersionCode + "' "; //load 64 bit CAB file for 64 bit Windows var temp = DW_IsTrial ? DW_TRAILCLASSID : DW_FULLCLASSID; objString += " classid='clsid:" + temp + "' viewastext>"; objString += " <param name='Manufacturer' value='DynamSoft Corporation' />"; objString += " <param name='ProductFamily' value='" + DW_ProductName + "' />"; objString += " <param name='ProductName' value='" + DW_ProductName + "' />"; //objString += " <param name='wmode' value='transparent'/> "; objString += " </object>"; } // For non-IE browsers, render the embed object else { objString = " <embed id='" + DW_ObjectName + "'style='display: inline; width:" + DW_Width + "px;height:" + DW_Height + "px' id='" + DW_ObjectName + "' type='" + DW_MIMETYPE + "'"; objString += " OnPostTransfer='Dynamsoft_OnPostTransfer' OnPostAllTransfers='Dynamsoft_OnPostAllTransfers'"; objString += " OnMouseClick='Dynamsoft_OnMouseClick' OnPostLoad='Dynamsoft_OnPostLoadfunction'"; objString += " OnImageAreaSelected = 'Dynamsoft_OnImageAreaSelected'"; objString += " OnImageAreaDeSelected = 'Dynamsoft_OnImageAreaDeselected'"; objString += " OnMouseDoubleClick = 'Dynamsoft_OnMouseDoubleClick'"; objString += " OnMouseRightClick = 'Dynamsoft_OnMouseRightClick'"; objString += " OnTopImageInTheViewChanged = 'Dynamsoft_OnTopImageInTheViewChanged'"; if (DW_InWindows) objString += " pluginspage='" + else objString += " pluginspage='" + DW_PKGPath + "'></embed>"; //load the Mac edition for Chrome, Firefox, Safari on Mac } DWTContainer = document.getElementById(DW_DWTContainerID); DWTContainer.innerHTML = objString; DWObject = document.getElementById(DW_ObjectName); }
扫描文档
通过TWAIN扫描识别控件可以从扫描仪中轻松捕获图像。下列JavaScript代码设置了像素类型,分辨率,扫描类型等。
function AcquireImageInner() { if (DW_DWTSourceContainerID == "") DWObject.SelectSource(); else DWObject.SelectSourceByIndex(document.getElementById(DW_DWTSourceContainerID).selectedIndex); //select from the available TWAIN devices DWObject.CloseSource(); DWObject.OpenSource(); DWObject.IfShowUI = document.getElementById("ShowUI").checked; var i; for (i = 0; i < 3; i++) { if (document.getElementsByName("PixelType").item(i).checked == true) DWObject.PixelType = i; } //set the pixel type of the image DWObject.Resolution = Resolution.value; DWObject.IfFeederEnabled = document.getElementById("ADF").checked; //whether scan from ADF or flatbed DWObject.IfDuplexEnabled = document.getElementById("Duplex").checked; //whether do duplex scan DWObject.IfDisableSourceAfterAcquire = true; DWObject.AcquireImage(); //acquire images from the scanner }
上传文档
将图像扫描至Dynamic Web TWAIN后,你可以通过HTTP Post方法,将扫描图像上传到Web服务器。
var DW_ActionPage = "SaveToFile"; //call SaveToFile controller function btnUpload_onclick(){ var i, strHTTPServer, strActionPage, strImageType; strHTTPServer = DW_ServerName; DWObject.HTTPPort = DW_strPort; var CurrentPathName = unescape(location.pathname); // get current PathName in plain ASCII var CurrentPath = CurrentPathName.substring(0, CurrentPathName.lastIndexOf("/") + 1); strActionPage = CurrentPath + DW_ActionPage; //the ActionPage's file path for(i=0;i<4;i++){ if(document.getElementsByName("ImageType").item(i).checked == true){ strImageType = i + 1; break; } } //choose the image type, JPEG, TIFF, PNG or PDF var uploadfilename = txt_fileName.value + "." + document.getElementsByName("ImageType").item(i).value; if (strImageType == 2 && document.getElementById("MultiPageTIFF").checked) { if ((DWObject.SelectedImagesCount == 1) || (DWObject.SelectedImagesCount == DWObject.HowManyImagesInBuffer)) { DWObject.HTTPUploadAllThroughPostAsMultiPageTIFF( strHTTPServer, strActionPage, uploadfilename ); { DWObject.HTTPUploadThroughPostAsMultiPageTIFF( strHTTPServer, strActionPage, uploadfilename ); } } //whether to upload the images as a multi-page TIFF file else if (strImageType == 4 && document.getElementById("MultiPagePDF").checked) { if ((DWObject.SelectedImagesCount == 1) || (DWObject.SelectedImagesCount == DWObject.HowManyImagesInBuffer)) { DWObject.HTTPUploadAllThroughPostAsPDF( strHTTPServer, strActionPage, uploadfilename ); } else { DWObject.HTTPUploadThroughPostAsMultiPagePDF( strHTTPServer, strActionPage, uploadfilename ); } } //whether to upload the images as a multi-page PDF file else { DWObject.HTTPUploadThroughPostEx( strHTTPServer, DWObject.CurrentImageIndexInBuffer, strActionPage, uploadfilename, strImageType ); }
Controller.cs
public String SaveToFile() { String strImageName; HttpFileCollectionBase files = Request.Files; HttpPostedFileBase uploadfile = files["RemoteFile"]; strImageName = uploadfile.FileName; uploadfile.SaveAs(Server.MapPath("~") + "\\UploadedImages\\" + strImageName); return ""; }