LEADTOOLS使用教程：從TWAIN源獲取圖像

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根據(jù)以下步驟，您可以創(chuàng)建一個簡單的LeadTools應(yīng)用程序，它可以從TWAIN源獲取圖像：

1. 打開Visual Studio .NET。

2. 點擊 文件->新建->項目…。

3. 打開新建項目對話框后，在模板中選擇"Visual C#"或"Visual Basic"，隨后選擇"Windows窗體應(yīng)用程序"。在名稱欄中輸入項目名稱"Acquiring an Image"，并使用"瀏覽"按鈕選擇您工程的存儲路徑，點擊"確定"。

4. 在"解決方案資源管理器"中，右擊"引用"，選擇"添加引用"。在"引用管理器"中，瀏覽選擇Leadtools For .NET文件夾" <LEADTOOLS_INSTALLDIR>\Bin\DotNet\Win32",選擇以下的DLL：

• Leadtools.dll
• Leadtools.Twain.dll
• Leadtools.Codecs.dll
• Leadtools.WinForms.dll

點擊"確定"按鈕，將以上所有的DLL添加到應(yīng)用程序中。

5. 將Form1調(diào)整到設(shè)計視圖，在工具箱（視圖->工具箱）拖拽一個RasterImageViewer實例至窗體。若您的工具箱沒有RasterImageViewer，點擊工具->選擇工具箱項…。點擊瀏覽從"<LEADTOOLS_INSTALLDIR>\Bin\DotNet\Win32"中選擇Leadtools.WinForms.DLL，點擊打開并確定。

6. 切換至Form1的設(shè)計視圖，從工具箱（視圖->工具箱）里拖拽3個RadioButton控件的實例至窗體上，根據(jù)以下表格修改屬性：

Text	Name	Checked
本機(jī)	radioNative	False
存儲器	radioMemory	False
文件	radioFile	False

7. 從工具箱（視圖->工具箱）拖拽4個Button控件的實例至窗體上，根據(jù)以下表格修改相關(guān)屬性：

Text	Name
獲取	buttonAcquire
選擇源	buttonSelectSource
保存模板文件	buttonSaveTemplateFile
加載模板文件	buttonLoadTemplateFile

8. 切換至Form1的代碼視圖，在文件開始添加以下代碼：

1: [C#] 
  2:    using Leadtools;
  3:    using Leadtools.Twain;
  4:    using Leadtools.Codecs;
  5:    using Leadtools.WinForms;

9. 聲明以下私有變量：

1: [C#] 
  2:    private TwainSession twnSession;

10. 為Form1的Load事件添加事件句柄，并添加以下代碼：

1: [C#] 
  2: 
  3: private void Form1_Load(object sender, System.EventArgs e)
  4: {
  5:    try
  6:    {
  7:       twnSession = new TwainSession();
  8:       twnSession.Startup(this, "manufacturer", "productFamily", "version", "application", TwainStartupFlags.None);
  9:    }
 10:    catch (Exception ex)
 11:    {
 12:       MessageBox.Show(this, ex.Message);
 13:    }
 14: }

11. 為Form1的Closing事件添加事件句柄，代碼如下：

1: [C#] 
  2: private void Form1_FormClosing(object sender, FormClosingEventArgs e)
  3: {
  4:    try
  5:    {
  6:       twnSession.Shutdown();
  7:    }
  8:    catch (Exception ex)
  9:    {
 10:       MessageBox.Show(this, ex.Message);
 11:    }
 12: }

12. 為twnSession AcquirePage事件添加事件句柄，并添加以下代碼：

1: [C#] 
  2: 
  3: private void twnSession_AcquirePage(object sender, TwainAcquirePageEventArgs e)
  4: {
  5:    rasterImageViewer1.Image = e.Image;
  6: }

13. 為buttonAcquire Click 事件添加事件句柄，并添加以下代碼：

1: [C#] 
  2: 
  3: private void buttonAcquire_Click(object sender, System.EventArgs e)
  4: {
  5:    try
  6:    {
  7:       twnSession.AcquirePage += new EventHandler<TwainAcquirePageEventArgs>(twnSession_AcquirePage);
  8:       twnSession.Acquire(TwainUserInterfaceFlags.Show);
  9:    }
 10:    catch (Exception ex)
 11:    {
 12:       MessageBox.Show(this, ex.Message);
 13:    }
 14: }

14. 為buttonSelectSource Click事件添加事件句柄，并添加以下代碼：

1: [C#] 
  2: 
  3: private void buttonSelectSource_Click(object sender, System.EventArgs e)
  4: {
  5:    try
  6:    {
  7:       twnSession.SelectSource(string.Empty);
  8:    }
  9:    catch (Exception ex)
 10:    {
 11:       MessageBox.Show(this, ex.Message);
 12:    }
 13: }

15. 為buttonSaveTemplateFile Click事件添加事件句柄，并添加以下代碼：

1: [C#] 
  2: 
  3: private void buttonSaveTemplateFile_Click(object sender, System.EventArgs e)
  4: {
  5:    try
  6:    {
  7:       twnSession.SaveTemplateFile(@"c:\test.ltt");
  8:    }
  9:    catch (Exception ex)
 10:    {
 11:       MessageBox.Show(this, ex.Message);
 12:    }
 13: }

16. 為buttonLoadTemplateFile Click事件添加事件句柄，并添加以下代碼：

1: [C#] 
  2: 
  3: private void buttonLoadTemplateFile_Click(object sender, System.EventArgs e)
  4: {
  5:    try
  6:    {
  7:       twnSession.LoadTemplateFile(@"c:\test.ltt");
  8:    }
  9:    catch (Exception ex)
 10:    {
 11:       MessageBox.Show(this, ex.Message);
 12:    }
 13: }

17. 為radioNative CheckedChanged事件添加事件句柄，并添加以下代碼：

1: [C#] 
  2: 
  3: private void radioNative_CheckedChanged(object sender, System.EventArgs e)
  4: {
  5:    try
  6:    {
  7:       TwainCapability capability = new TwainCapability();
  8:       capability.Information.ContainerType = TwainContainerType.OneValue;
  9:       capability.Information.Type = TwainCapabilityType.ImageTransferMechanism;
 10:       capability.OneValueCapability.ItemType = TwainItemType.Uint16;
 11:       capability.OneValueCapability.Value = (UInt16)TwainTransferMechanism.Native;
 12:       twnSession.SetCapability(capability, TwainSetCapabilityMode.Set);
 13:    }
 14:    catch (Exception ex)
 15:    {
 16:       MessageBox.Show(this, ex.Message);
 17:    }
 18: }

18. 為radioMemory CheckedChanged事件添加事件句柄，代碼如下：

1: [C#] 
  2: 
  3: private void radioMemory_CheckedChanged(object sender, System.EventArgs e)
  4: {
  5:    try
  6:    {
  7:       TwainCapability capability = new TwainCapability();
  8:       capability.Information.ContainerType = TwainContainerType.OneValue;
  9:       capability.Information.Type = TwainCapabilityType.ImageTransferMechanism;
 10:       capability.OneValueCapability.ItemType = TwainItemType.Uint16;
 11:       capability.OneValueCapability.Value = (UInt16)TwainTransferMechanism.Memory;
 12:       twnSession.SetCapability(capability, TwainSetCapabilityMode.Set);
 13:    }
 14:    catch (Exception ex)
 15:    {
 16:       MessageBox.Show(this, ex.Message);
 17:    }
 18: }

19. 為radioFile CheckedChanged事件添加事件句柄，代碼如下：

1: [C#] 
  2: 
  3: private void radioFile_CheckedChanged(object sender, System.EventArgs e)
  4: {
  5:    try
  6:    {
  7:       TwainCapability capability = new TwainCapability();
  8:       capability.Information.ContainerType = TwainContainerType.OneValue;
  9:       capability.Information.Type = TwainCapabilityType.ImageTransferMechanism;
 10:       capability.OneValueCapability.ItemType = TwainItemType.Uint16;
 11:       capability.OneValueCapability.Value = (UInt16)TwainTransferMechanism.File;
 12:       twnSession.SetCapability(capability, TwainSetCapabilityMode.Set);
 13:    }
 14:    catch (Exception ex)
 15:    {
 16:       MessageBox.Show(this, ex.Message);
 17:    }
 18: }

20. 編譯并運行程序。

轉(zhuǎn)載來自http://blog.gcpowertools.com.cn/post/2014/09/09/acquire-an-image-by-leadtools.aspx