CommandID Constants
Specifies common Device and Item commands as String versions of GUIDs.
Constant/value | Description |
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CommandID for Synchronize. Causes the device driver to synchronize cached items with the hardware device. |
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CommandID for Take Picture. Causes a WIA device to acquire an image. |
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CommandID for Delete All Items. Notifies the device to delete all items that can be deleted from the device. |
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CommandID for Change Document. Causes the document scanner to load the next page in its document handler. Does not apply to other device types. |
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CommandID for Unload Document. Notifies the document scanner to unload all remaining pages in its document handler. Does not apply to other device types. |
Remarks
Use a CommandID Constants constant as the value for the CommandID parameter for the ExecuteCommand (Device) and ExecuteCommand (Item) methods. You can also use a CommandID Constants constant as the value of the CommandID properties in a DeviceCommand object.
The following example shows how to signal a camera to take a picture if the device selected is a camera.
Dim dev 'As Device
Set dev = CommonDialog1.ShowSelectDevice
If dev.Type = CameraDeviceType Then
Dim itm 'As Item
Set itm = dev.ExecuteCommand(wiaCommandTakePicture)
End If
Similar to the previous code example, the following example shows how to determine if the selected device supports the wiaCommandTakePicture command.
Dim dev 'As Device
Dim dc 'As DeviceCommand
Set dev = CommonDialog1.ShowSelectDevice
For Each dc In dev.Commands
If dc.CommandID = wiaCommandTakePicture Then
MsgBox "Selected device supports the TakePicture command"
End If
End If
Requirements
Minimum supported client |
Windows Vista [desktop apps only] |
Minimum supported server |
Windows Server 2003 R2 [desktop apps only] |
Header |
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IDL |
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