使用 WIA、C# 和 Win 7 进行相机捕捉
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【中文标题】使用 WIA、C# 和 Win 7 进行相机捕捉【英文标题】：Camera Capture with WIA, C# and Win 7 【发布时间】：2011-08-15 08:55:45 【问题描述】：我尝试在 Windows 7 上使用 WIA 2.0、C#、.net 4.0 从网络摄像头拍照。我尝试了许多不同的示例，但没有任何效果。我总是得到这个异常：“ComException 未处理”来自 HRESULT 的异常：0x80210015”。代码是WIA_S_NO_DEVICE_AVAILABLE。我检查了 WIA-Service 是否正在运行以及摄像头是否出现在扫描仪和相机中。我没有知道这里出了什么问题！有人可以帮忙吗？
在这一行抛出异常：
设备 d = class1.ShowSelectDevice(WiaDeviceType.CameraDeviceType, true, false);:
这里是代码
string DeviceID;
const string wiaFormatBMP = "B96B3CAB-0728-11D3-9D7B-0000F81EF32E";
const string wiaFormatPNG = "B96B3CAF-0728-11D3-9D7B-0000F81EF32E";
const string wiaFormatGIF = "B96B3CB0-0728-11D3-9D7B-0000F81EF32E";
const string wiaFormatJPEG = "B96B3CAE-0728-11D3-9D7B-0000F81EF32E";
const string wiaFormatTIFF = "B96B3CB1-0728-11D3-9D7B-0000F81EF32E";
class WIA_DPS_DOCUMENT_HANDLING_SELECT
public const uint FEEDER = 0x00000001;
public const uint FLATBED = 0x00000002;
class WIA_DPS_DOCUMENT_HANDLING_STATUS
public const uint FEED_READY = 0x00000001;
class WIA_PROPERTIES
public const uint WIA_RESERVED_FOR_NEW_PROPS = 1024;
public const uint WIA_DIP_FIRST = 2;
public const uint WIA_DPA_FIRST = WIA_DIP_FIRST + WIA_RESERVED_FOR_NEW_PROPS;
public const uint WIA_DPC_FIRST = WIA_DPA_FIRST + WIA_RESERVED_FOR_NEW_PROPS;
//
// Scanner only device properties (DPS)
//
public const uint WIA_DPS_FIRST = WIA_DPC_FIRST + WIA_RESERVED_FOR_NEW_PROPS;
public const uint WIA_DPS_DOCUMENT_HANDLING_STATUS = WIA_DPS_FIRST + 13;
public const uint WIA_DPS_DOCUMENT_HANDLING_SELECT = WIA_DPS_FIRST + 14;
class WIA_ERRORS
public const uint BASE_VAL_WIA_ERROR = 0x80210000;
public const uint WIA_ERROR_PAPER_EMPTY = BASE_VAL_WIA_ERROR + 3;
public void ADFScan()
//Choose Scanner
CommonDialogClass class1 = new CommonDialogClass();
Device d = class1.ShowSelectDevice(WiaDeviceType.CameraDeviceType, true, false);
if (d != null)
this.DeviceID = d.DeviceID;
else
//no scanner chosen
return;
WIA.CommonDialog WiaCommonDialog = new CommonDialogClass();
bool hasMorePages = true;
int x = 0;
int numPages = 0;
while (hasMorePages)
//Create DeviceManager
DeviceManager manager = new DeviceManagerClass();
Device WiaDev = null;
foreach (DeviceInfo info in manager.DeviceInfos)
if (info.DeviceID == this.DeviceID)
WIA.Properties infoprop = null;
infoprop = info.Properties;
//connect to scanner
WiaDev = info.Connect();
break;
//Start Scan
WIA.ImageFile img = null;
WIA.Item Item = WiaDev.Items[1] as WIA.Item;
try
img = (ImageFile)WiaCommonDialog.ShowTransfer(Item, wiaFormatJPEG, false);
//process image:
//one would do image processing here
//
//Save to file
string varImageFileName = "c:\\test" + x.ToString() + ".jpg";
if (File.Exists(varImageFileName))
//file exists, delete it
File.Delete(varImageFileName);
img.SaveFile(varImageFileName);
numPages++;
img = null;
catch (Exception ex)
MessageBox.Show("Error: " + ex.Message);
finally
Item = null;
//determine if there are any more pages waiting
Property documentHandlingSelect = null;
Property documentHandlingStatus = null;
foreach (Property prop in WiaDev.Properties)
if (prop.PropertyID == WIA_PROPERTIES.WIA_DPS_DOCUMENT_HANDLING_SELECT)
documentHandlingSelect = prop;
if (prop.PropertyID == WIA_PROPERTIES.WIA_DPS_DOCUMENT_HANDLING_STATUS)
documentHandlingStatus = prop;
hasMorePages = false; //assume there are no more pages
if (documentHandlingSelect != null)
//may not exist on flatbed scanner but required for feeder
//check for document feeder
if ((Convert.ToUInt32(documentHandlingSelect.get_Value()) & WIA_DPS_DOCUMENT_HANDLING_SELECT.FEEDER) != 0)
hasMorePages = ((Convert.ToUInt32(documentHandlingStatus.get_Value()) & WIA_DPS_DOCUMENT_HANDLING_STATUS.FEED_READY) != 0);
x++;
感谢您的帮助！
【问题讨论】：
显示在扫描仪和相机下的设备不一定是相机。您的代码仅请求摄像头。你得到的错误是你没有这种类型的设备。 【参考方案1】：这是 Microsoft 未记录错误的典型示例...错误代码仅表示未找到任何设备，未连接或未识别 WIA。
【讨论】：
【参考方案2】：如果有摄像头连接，尝试添加类似CameraTest的方法进行测试：
bool CameraTest()
bool present = false;
try
Device d = class1.ShowSelectDevice(WiaDeviceType.CameraDeviceType, true, false);
present = true;
catch (Exception ex)
return present;
【讨论】：
【参考方案3】：试试下面的代码：
class WIAScanner
const string wiaFormatBMP = "B96B3CAB-0728-11D3-9D7B-0000F81EF32E";
class WIA_DPS_DOCUMENT_HANDLING_SELECT
public const uint FEEDER = 0x00000001;
public const uint FLATBED = 0x00000002;
class WIA_DPS_DOCUMENT_HANDLING_STATUS
public const uint FEED_READY = 0x00000001;
class WIA_PROPERTIES
public const uint WIA_RESERVED_FOR_NEW_PROPS = 1024;
public const uint WIA_DIP_FIRST = 2;
public const uint WIA_DPA_FIRST = WIA_DIP_FIRST + WIA_RESERVED_FOR_NEW_PROPS;
public const uint WIA_DPC_FIRST = WIA_DPA_FIRST + WIA_RESERVED_FOR_NEW_PROPS;
//
// Scanner only device properties (DPS)
//
public const uint WIA_DPS_FIRST = WIA_DPC_FIRST + WIA_RESERVED_FOR_NEW_PROPS;
public const uint WIA_DPS_DOCUMENT_HANDLING_STATUS = WIA_DPS_FIRST + 13;
public const uint WIA_DPS_DOCUMENT_HANDLING_SELECT = WIA_DPS_FIRST + 14;
/// <summary>
/// Use scanner to scan an image (with user selecting the scanner from a dialog).
/// </summary>
/// <returns>Scanned images.</returns>
public static List<Image> Scan()
WIA.ICommonDialog dialog = new WIA.CommonDialog();
WIA.Device device = dialog.ShowSelectDevice(WIA.WiaDeviceType.UnspecifiedDeviceType, true, false);
if (device != null)
return Scan(device.DeviceID);
else
throw new Exception("You must select a device for scanning.");
/// <summary>
/// Use scanner to scan an image (scanner is selected by its unique id).
/// </summary>
/// <param name="scannerName"></param>
/// <returns>Scanned images.</returns>
public static List<Image> Scan(string scannerId)
List<Image> images = new List<Image>();
bool hasMorePages = true;
while (hasMorePages)
// select the correct scanner using the provided scannerId parameter
WIA.DeviceManager manager = new WIA.DeviceManager();
WIA.Device device = null;
foreach (WIA.DeviceInfo info in manager.DeviceInfos)
if (info.DeviceID == scannerId)
// connect to scanner
device = info.Connect();
break;
// device was not found
if (device == null)
// enumerate available devices
string availableDevices = "";
foreach (WIA.DeviceInfo info in manager.DeviceInfos)
availableDevices += info.DeviceID + "\n";
// show error with available devices
throw new Exception("The device with provided ID could not be found. Available Devices:\n" + availableDevices);
WIA.Item item = device.Items[1] as WIA.Item;
try
// scan image
WIA.ICommonDialog wiaCommonDialog = new WIA.CommonDialog();
WIA.ImageFile image = (WIA.ImageFile)wiaCommonDialog.ShowTransfer(item, wiaFormatBMP, false);
// save to temp file
string fileName = Path.GetTempFileName();
File.Delete(fileName);
image.SaveFile(fileName);
image = null;
// add file to output list
images.Add(Image.FromFile(fileName));
catch (Exception exc)
throw exc;
finally
item = null;
//determine if there are any more pages waiting
WIA.Property documentHandlingSelect = null;
WIA.Property documentHandlingStatus = null;
foreach (WIA.Property prop in device.Properties)
if (prop.PropertyID == WIA_PROPERTIES.WIA_DPS_DOCUMENT_HANDLING_SELECT)
documentHandlingSelect = prop;
if (prop.PropertyID == WIA_PROPERTIES.WIA_DPS_DOCUMENT_HANDLING_STATUS)
documentHandlingStatus = prop;
// assume there are no more pages
hasMorePages = false;
// may not exist on flatbed scanner but required for feeder
if (documentHandlingSelect != null)
// check for document feeder
if ((Convert.ToUInt32(documentHandlingSelect.get_Value()) & WIA_DPS_DOCUMENT_HANDLING_SELECT.FEEDER) != 0)
hasMorePages = ((Convert.ToUInt32(documentHandlingStatus.get_Value()) & WIA_DPS_DOCUMENT_HANDLING_STATUS.FEED_READY) != 0);
return images;
/// <summary>
/// Gets the list of available WIA devices.
/// </summary>
/// <returns></returns>
public static List<string> GetDevices()
List<string> devices = new List<string>();
WIA.DeviceManager manager = new WIA.DeviceManager();
foreach (WIA.DeviceInfo info in manager.DeviceInfos)
devices.Add(info.DeviceID);
return devices;
【讨论】：
为什么我投了反对票？...解释一下这个答案有什么问题？ 什么是“试试这个”？这是一个答案吗？它有什么帮助？您的ShowSelectDevice 与所讨论的完全相同。这不是一个有效的答案，它没有解释问题，它没有提供解决方法。这只是一段冒险的代码。以上是关于使用 WIA、C# 和 Win 7 进行相机捕捉的主要内容，如果未能解决你的问题，请参考以下文章
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