TwainDotNet System.TypeInitializationException错误

Question

我正在尝试将TWAIN支持添加到我已经编写了一段时间的程序中。我正在使用来自https://github.com/tmyroadctfig/twaindotnet的TwainDotNet

我已经能够毫无问题地将vb.net示例应用到新的测试项目中。但是，当我将它放入当前项目的表单中时，我得到了一个错误。

代码：

Imports System.Windows.Forms
Imports TwainDotNet
Imports TwainDotNet.TwainNative
Imports TwainDotNet.WinFroms

Public Class frmDebug

    Private Property areaSettings As New AreaSettings(Units.Centimeters, 0.1F, 5.7F, 0.1F + 2.6F, 5.7F + 2.6F)
    Private Property twain As Twain
    Private Property settings As ScanSettings
    Private Property images As List(Of System.Drawing.Bitmap)

    Public Sub New()

        ' This call is required by the designer.
        InitializeComponent()

        ' Twain needs a hook into this Form's message loop to work:
        twain = New Twain(New WinFormsWindowMessageHook(Me))

        ' Add a handler to grab each image as it comes off the scanner
        AddHandler twain.TransferImage,
            Sub(sender As Object, args As TwainDotNet.TransferImageEventArgs)
                If (Not (args.Image Is Nothing)) Then
                    imgScanner.Image = args.Image

                    images.Add(args.Image)

                    'widthLabel.Text = String.Format("Width: {0}", pictureBox1.Image.Width)
                    'heightLabel.Text = String.Format("Height: {0}", pictureBox1.Image.Height)
                End If
            End Sub

        ' Re-enable the form after scanning completes
        AddHandler twain.ScanningComplete,
            Sub(sender As Object, e As TwainDotNet.ScanningCompleteEventArgs)
                Enabled = True
            End Sub
    End Sub

    Private Sub cmdSource_Click(sender As Object, e As EventArgs) Handles cmdSource.Click
        ' Show the "select scanning source" dialog
        twain.SelectSource()
    End Sub
End Class

错误：

'Program.vshost.exe' (CLR v4.0.30319: Program.vshost.exe): Loaded 'D:\Programming\Program\Program\bin\x86\Debug\TwainDotNet.dll'. Symbols loaded.
'Program.vshost.exe' (CLR v4.0.30319: Program.vshost.exe): Loaded 'D:\Programming\Program\Program\bin\x86\Debug\TwainDotNet.WinFroms.dll'. Symbols loaded.
'Program.vshost.exe' (CLR v4.0.30319: Program.vshost.exe): Loaded 'D:\Programming\Program\Program\bin\x86\Debug\Program-CustomDlls.dll'. Symbols loaded.
Exception thrown: 'System.TypeInitializationException' in TwainDotNet.dll

它终止的代码如下：

using System;
using System.Collections.Generic;
using System.Text;
using System.Reflection;
using System.Runtime.InteropServices;
using TwainDotNet.TwainNative;
using TwainDotNet.Win32;
using System.Drawing;

namespace TwainDotNet
{
    public class Twain
    {
        DataSourceManager _dataSourceManager;

        public Twain(IWindowsMessageHook messageHook)
        {
            ScanningComplete += delegate { };
            TransferImage += delegate { };

            _dataSourceManager = new DataSourceManager(DataSourceManager.DefaultApplicationId, messageHook);
            _dataSourceManager.ScanningComplete += delegate(object sender, ScanningCompleteEventArgs args)
            {
                ScanningComplete(this, args);
            };
            _dataSourceManager.TransferImage += delegate(object sender, TransferImageEventArgs args)
            {
                TransferImage(this, args);
            };
        }

        /// <summary>
        /// Notification that the scanning has completed.
        /// </summary>
        public event EventHandler<ScanningCompleteEventArgs> ScanningComplete;

        public event EventHandler<TransferImageEventArgs> TransferImage;

        /// <summary>
        /// Starts scanning.
        /// </summary>
        public void StartScanning(ScanSettings settings)
        {
            _dataSourceManager.StartScan(settings);
        }

        /// <summary>
        /// Shows a dialog prompting the use to select the source to scan from.
        /// </summary>
        public void SelectSource()
        {
            _dataSourceManager.SelectSource();
        }

        /// <summary>
        /// Selects a source based on the product name string.
        /// </summary>
        /// <param name="sourceName">The source product name.</param>
        public void SelectSource(string sourceName)
        {
            var source = DataSource.GetSource(
                sourceName,
                _dataSourceManager.ApplicationId,
                _dataSourceManager.MessageHook);

            _dataSourceManager.SelectSource(source);
        }

        /// <summary>
        /// Gets the product name for the default source.
        /// </summary>
        public string DefaultSourceName
        {
            get
            {
                using (var source = DataSource.GetDefault(_dataSourceManager.ApplicationId, _dataSourceManager.MessageHook))
                {
                    return source.SourceId.ProductName;
                }
            }
        }

        /// <summary>
        /// Gets a list of source product names.
        /// </summary>
        public IList<string> SourceNames
        {
            get
            {
                var result = new List<string>();
                var sources = DataSource.GetAllSources(
                    _dataSourceManager.ApplicationId,
                    _dataSourceManager.MessageHook);

                foreach (var source in sources)
                {
                    result.Add(source.SourceId.ProductName);
                    source.Dispose();
                }

                return result;
            }
        }
    }
}

第21行：_dataSourceManager =新DataSourceManager(DataSourceManager.DefaultApplicationId，messageHook)；

我不知道它为什么会死，调试消息也很模糊。你有什么想法吗？

Answer 1

问题是由于我正在为哪种CPU类型编译。我为x86重新编译了TwainDotNet的代码。然后，我将我的主程序设置为为x86编译。它现在起作用了。

我一直在为AnyCPU编译。log4net.dll是为x86编译的，TwainDotNet需要它。我也认为Twain是为x86编写的，但我不知道。

不用说，我现在正在为x86架构进行编译。