IEnumWiaItem::Next method (wia_xp.h)

Article
10/13/2021

The IEnumWiaItem::Next method fills an array of pointers to IWiaItem interfaces.

Syntax

HRESULT Next(
  [in]      ULONG    celt,
  [out]     IWiaItem **ppIWiaItem,
  [in, out] ULONG    *pceltFetched
);

Parameters

[in] celt

Type: ULONG

Specifies the number of array elements in the array indicated by the ppIWiaItem parameter.

[out] ppIWiaItem

Type: IWiaItem**

Receives the address of an array of IWiaItem interface pointers. IEnumWiaItem::Next fills this array with interface pointers.

[in, out] pceltFetched

Type: ULONG*

On output, this parameter receives the number of interface pointers actually stored in the array indicated by the ppIWiaItem parameter. When the enumeration is complete, this parameter will contain zero.

Return value

Type: HRESULT

If the method succeeds, the method returns S_OK. When the enumeration is complete, it returns S_FALSE. If the method fails, it returns a standard COM error code.

Remarks

The Windows Image Acquisition (WIA) run-time system represents WIA hardware devices as a hierarchical tree of IWiaItem objects. Applications use the IEnumWiaItem::Next method to obtain an IWiaItem interface pointer for each item in the current folder of a hardware device's IWiaItem object tree.

To obtain the list of pointers, the application passes an array of IWiaItem interface pointers that it allocates. It also passes the number of array elements in the celt parameter. The IEnumWiaItem::Next method fills the array with pointers to IWiaItem interfaces.

Until the enumeration process completes, the IEnumWiaItem::Next method returns S_OK. Each time it does, it sets the value pointed to by pceltFetched to the number of items it inserted into the array. When IEnumWiaItem::Next finishes the process of enumerating IWiaItem objects, it returns S_FALSE and sets the memory location pointed to by pceltFetched to zero.

Applications must call the IUnknown::Release method on the interface pointers they receive through the ppIWiaItem parameter.

Requirements

Requirement	Value
Minimum supported client	Windows 2000 Professional, Windows XP [desktop apps only]
Minimum supported server	Windows Server 2003 [desktop apps only]
Target Platform	Windows
Header	wia_xp.h (include Wia.h)
Library	Wiaguid.lib

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