VintaSoft Twain .NET SDK 15.1: Документация для Веб разработчика
В этом разделе
    Как установить значение возможности/опции TWAIN/SANE сканера?
    В этом разделе
    TWAIN стандарт определяет множество стандартных возможностей (XferCount, IPixelType, DoubleFeedDetection, IContrast, IRotation, ...), которые могут поддерживаться TWAIN устройством. Также TWAIN устройство может предоставлять пользовательские возможности, определяемые производителем сканера.

    Если Вы хотите установить текущее значение возможности TWAIN устройства, используйте функцию WebTwainDeviceJS.setCapability.



    SANE API не определяет стандартные опции для SANE устройства, SANE API просто определяет правила, которые позволяют создавать опции, которые являются самодокументированными.

    Если Вы хотите установить текущее значение опции SANE устройства, используйте функцию WebTwainDeviceJS.setCapability.



    Вот JavaScript код, который демонстрирует как установить значение возможности DuplexEnabled для TWAIN/SANE сканера:
    // set value of DuplexEnabled capability of TWAIN/SANE scanner
    __setDuplexEnabledCapValueOfTwainScanner();
    
    
    
    /**
     * Sets value of DuplexEnabled capability of TWAIN/SANE scanner.
     */
    function __setDuplexEnabledCapValueOfTwainScanner() {
        // register the evaluation version of VintaSoft Web TWAIN service
        // please read how to get evaluation license in documentation: https://www.vintasoft.ru/docs/vstwain-dotnet-web/Licensing-Twain_Web-Evaluation.html
        Vintasoft.Twain.WebTwainGlobalSettingsJS.register('REG_USER', 'REG_URL', 'REG_CODE', 'EXPIRATION_DATE');
    
        // URL to the VintaSoft Web TWAIN service
        var serviceUrl = 'https://localhost:25329/api/VintasoftTwainApi';
        // a Web API controller that allows to work with TWAIN and SANE devices
        var twainService = new Vintasoft.Shared.WebServiceControllerJS(serviceUrl);
    
        // TWAIN/SANE device manager
        var deviceManager = new Vintasoft.Twain.WebTwainDeviceManagerJS(twainService);
    
        // the default settings of device manager
        var deviceManagerInitSetting = new Vintasoft.Twain.WebTwainDeviceManagerInitSettingsJS();
    
        var device = null;
        try {
            // open device manager
            deviceManager.open(deviceManagerInitSetting);
    
            // get the default TWAIN/SANE device
            device = deviceManager.get_DefaultDevice();
    
            // open TWAIN device (do not display device UI but display dialog with image scanning progress)
            device.open(false, true);
    
            // if device is SANE device
            if (device.get_DeviceName().substring(0, 4) == "Sane") {
                // specify that images must be acquired from source "ADF Duplex"
                device.set_SaneScanSource("ADF Duplex");
            }
            // if device is TWAIN device
            else {
                // set value of DuplexEnabled capability of TWAIN scanner
                device.setCapability(new Vintasoft.Twain.WebDeviceCapabilityIdEnumJS("DuplexEnabled"), true);
            }
    
            var acquireModalState;
            do {
                // do one step of modal image acquisition process
                var acquireModalResult = device.acquireModalSync();
                // get state of image acquisition
                acquireModalState = acquireModalResult.get_AcquireModalState().valueOf();
    
                switch (acquireModalState) {
                    case 2:   // image is acquired
                        // get acquired image
                        var acquiredImage = acquireModalResult.get_AcquiredImage();
                        // get image as Base64 string
                        var bitmapAsBase64String = acquiredImage.getAsBase64String();
                        // update image preview
                        var previewImageElement = document.getElementById('previewImage');
                        previewImageElement.src = bitmapAsBase64String;
                        break;
                    case 4:   // image scan is failed
                        alert(acquireModalResult.get_ErrorMessage());
                        break;
                    case 9:   // image scan is finished
                        break;
                }
            }
            while (acquireModalState !== 0);
        }
        catch (ex) {
            alert(ex);
        }
        finally {
            if (device != null) {
                // close the device
                device.close();
            }
            // close the device manager
            deviceManager.close();
        }
    }
    
    


    Вот TypeScript код, который демонстрирует как установить значение возможности DuplexEnabled для TWAIN/SANE сканера:
    import { Component } from '@angular/core';
    
    @Component({
      selector: 'twain-scanning-demo',
      templateUrl: './twain-scanning-demo.component.html'
    })
    export class TwainScanningDemoComponent {
    
      ngOnInit() {
        // set value of DuplexEnabled capability of TWAIN/SANE scanner
        this.__setDuplexEnabledCapValueOfTwainScanner();
      }
    
    
      /**
       * Sets value of DuplexEnabled capability of TWAIN/SANE scanner.
       */
      __setDuplexEnabledCapValueOfTwainScanner() {
        // register the evaluation version of VintaSoft Web TWAIN service
        // please read how to get evaluation license in documentation: https://www.vintasoft.ru/docs/vstwain-dotnet-web/Licensing-Twain_Web-Evaluation.html
        Vintasoft.Twain.WebTwainGlobalSettingsJS.register('REG_USER', 'REG_URL', 'REG_CODE', 'EXPIRATION_DATE');
    
        // URL to the VintaSoft Web TWAIN service
        let serviceUrl: string = 'https://localhost:25329/api/VintasoftTwainApi';
        // a Web API controller that allows to work with TWAIN and SANE devices
        let twainService: Vintasoft.Shared.WebServiceControllerJS = new Vintasoft.Shared.WebServiceControllerJS(serviceUrl);
    
        // TWAIN/SANE device manager
        let deviceManager: Vintasoft.Twain.WebTwainDeviceManagerJS = new Vintasoft.Twain.WebTwainDeviceManagerJS(twainService);
    
        // the default settings of device manager
        let deviceManagerInitSetting: Vintasoft.Twain.WebTwainDeviceManagerInitSettingsJS = new Vintasoft.Twain.WebTwainDeviceManagerInitSettingsJS();
    
        try {
          // open device manager
          deviceManager.open(deviceManagerInitSetting);
        }
        catch (ex) {
          alert(ex);
          return;
        }
    
        let device: Vintasoft.Twain.WebTwainDeviceJS = null;
        try {
          // get the default TWAIN/SANE device
          device = deviceManager.get_DefaultDevice();
    
          // open TWAIN device (do not display device UI but display dialog with image scanning progress)
          device.open(false, true);
    
          // if device is SANE device
          if (device.get_DeviceName().substring(0, 4) == "Sane") {
            // specify that images must be acquired from source "ADF Duplex"
            device.set_SaneScanSource("ADF Duplex");
          }
          // if device is TWAIN device
          else {
            // set value of DuplexEnabled capability of TWAIN scanner
            device.setCapability(new Vintasoft.Twain.WebDeviceCapabilityIdEnumJS("DuplexEnabled"), true);
          }
    
          let acquireModalState: number;
          do {
            // do one step of modal image acquisition process
            let acquireModalResult: Vintasoft.Twain.WebTwainDeviceAcquireModalResultJS = device.acquireModalSync();
            // get state of image acquisition
            acquireModalState = acquireModalResult.get_AcquireModalState().valueOf() as number;
    
            switch (acquireModalState) {
              case 2:   // image is acquired
                // get acquired image
                let acquiredImage: Vintasoft.Twain.WebAcquiredImageJS = acquireModalResult.get_AcquiredImage();
                // get image as Base64 string
                let bitmapAsBase64String: string = acquiredImage.getAsBase64String();
                // update image preview
                let previewImageElement: HTMLImageElement = document.getElementById('previewImage') as HTMLImageElement;
                previewImageElement.src = bitmapAsBase64String;
                break;
              case 4:   // image scan is failed
                alert(acquireModalResult.get_ErrorMessage());
                break;
              case 9:   // image scan is finished
                break;
            }
          }
          while (acquireModalState !== 0);
        }
        catch (ex) {
          alert(ex);
        }
        finally {
          if (device != null) {
            // close the device
            device.close();
          }
          // close the device manager
          deviceManager.close();
        }
      }
    
    }