IWiaMiniDrv::drvGetDeviceErrorStr method (wiamindr_lh.h)

Artikel
02/22/2024

The IWiaMiniDrv::drvGetDeviceErrorStr method maps an error code to a Unicode string that describes the error.

Syntax

HRESULT drvGetDeviceErrorStr(
  LONG     __MIDL__IWiaMiniDrv0039,
  LONG     __MIDL__IWiaMiniDrv0040,
  LPOLESTR *__MIDL__IWiaMiniDrv0041,
  LONG     *__MIDL__IWiaMiniDrv0042
);

Parameters

__MIDL__IWiaMiniDrv0039

lDevErrVal [in]

Specifies the device error value to be mapped to a string. A value of zero indicates that no error occurred.

__MIDL__IWiaMiniDrv0040

lFlags [in]

Reserved.

__MIDL__IWiaMiniDrv0041

plDevErr [out]

Points to a memory location that will receive a status code for this method. If this method returns S_OK, the value stored will be zero. Otherwise, a minidriver-specific error code will be stored at the location pointed to by this parameter.

__MIDL__IWiaMiniDrv0042

ppszDevErrStr [out, optional]

Points to a memory location that will receive the address of a string describing the error.

Return value

On success, the method should return S_OK and clear the device error value pointed to by plDevErr. If the minidriver does not fully implement this method, the method should return E_NOTIMPL. If the minidriver does not recognize the error value passed to this method, the method should return E_INVALIDARG. If the method fails, it should return a standard COM error code and place a minidriver-specific error code value in the memory pointed to by plDevErr.

Remarks

To obtain an error string that describes a device-specific minidriver-generated error value, the WIA service calls the IWiaMiniDrv::drvGetDeviceErrorStr method. In response to this call, the minidriver should use CoTaskMemAlloc to allocate memory that will contain a localized Unicode string corresponding to the error code passed to the minidriver. The WIA service (or an application) will free the memory. It is likely that an application will display the string, so it should be meaningful to an end user. The string should be loaded from a resource file, so that it can be localized into a variety of languages.

Requirements

Requirement	Value
Target Platform	Desktop
Header	wiamindr_lh.h (include Wiamindr.h)

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