Windows图像获取-在C#中设置设备属性 [英] Windows image acquisition - setting device properties in C#

问题描述

我有一个C#(WinForm)程序，该程序支持使用WIA进行扫描.我试图在扫描一个或多个文档之前设置设备属性.首先，我想设置扫描仪的纸张尺寸.以下是代码片段:

I have a C# (WinForm) program that supports scanning using WIA. I am trying to set device properties before scanning one or more documents. Primarily I want to set the paper size for the scanner. Following is a snippet of the code:

foreach (Property property in selectedDevice.Properties)
{
   //WiaProperties.WiaDpsHorizontalBedSize is my constant
   if (property.PropertyID == WiaProperties.WiaDpsHorizontalBedSize)
   {
       //Set property value here...             
   }
}

我正在找到水平床尺寸"属性，但问题是如何将其设置为一个值?没有属性的set_Value属性，但这似乎需要对结果对象的引用.因此，我不知道如何设置设备的属性?

I am finding the Horizontal Bed Size property, but the question is how do I set it to a value? There is a set_Value property off of property but that seems to take a ref to a result object. So I am at a loss as to how can I set properties on a device?

推荐答案

我也正在研究一个扫描项目，并且很少有WIA示例.这段代码是您想要设置床大小，DPI等的内容.请查看SetProperty方法，并提供有关如何处理set_Value的示例.

I am working on a scanning project as well, and there are very few WIA examples. This code is what you are looking for to set the bed size, DPI, etc. Check out the SetProperty method with an example on how to deal with set_Value.

class Scan
{
    // Scanner only device properties (DPS)
    public const int WIA_RESERVED_FOR_NEW_PROPS = 1024;
    public const int WIA_DIP_FIRST = 2;
    public const int WIA_DPA_FIRST = WIA_DIP_FIRST + WIA_RESERVED_FOR_NEW_PROPS;
    public const int WIA_DPC_FIRST = WIA_DPA_FIRST + WIA_RESERVED_FOR_NEW_PROPS;
    public const int WIA_DPS_FIRST = WIA_DPC_FIRST + WIA_RESERVED_FOR_NEW_PROPS;
    public const int WIA_DPS_DOCUMENT_HANDLING_STATUS = WIA_DPS_FIRST + 13;
    public const int WIA_DPS_DOCUMENT_HANDLING_SELECT = WIA_DPS_FIRST + 14;
    public const int FEEDER = 1;
    public const int FLATBED = 2;
    public const int DUPLEX = 4;
    public const int FEED_READY = 1;

    WIA.CommonDialog _dialog = new WIA.CommonDialog();
    WIA.Device _scanner;

    public void ADFScan()
    {

        _dialog = new CommonDialogClass();
        _scanner = _dialog.ShowSelectDevice(WIA.WiaDeviceType.ScannerDeviceType, false, false);


        foreach (Property item in _scanner.Items[1].Properties)
        {
            switch (item.PropertyID)
            {
                case 6146: //4 is Black-white,gray is 2, color 1
                    SetProperty(item, 2);
                    break;
                case 6147: //dots per inch/horizontal 
                    SetProperty(item, 100);
                    break;
                case 6148: //dots per inch/vertical 
                    SetProperty(item, 100);
                    break;
                case 6149: //x point where to start scan 
                    SetProperty(item, 0);
                    break;
                case 6150: //y-point where to start scan 
                    SetProperty(item, 0);
                    break;
                case 6151: //horizontal exent 
                    SetProperty(item, (int)(8.5 * 100));
                    break;
                case 6152: //vertical extent 
                    SetProperty(item, 11 * 100);
                    break;
            }
        }
        ImageFile image = (ImageFile)_scanner.Items[1].Transfer(FormatID.wiaFormatPNG);
        System.IO.File.Delete("tmp.png");
        image.SaveFile("tmp.png");
    }

    private void SetProperty(Property property, int value)
    {
        IProperty x = (IProperty)property;
        Object val = value;
        x.set_Value(ref val);
    }


    public void test()
    {
        bool WantsToScan = true;
        while (WantsToScan) ScanAndSaveOnePage();

    }


    static void Main(string[] args)
    {
        new Scan().test();
    }
}

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