DataObject.IDataObject.GetCanonicalFormatEtc Method (FORMATETC, FORMATETC)


This API supports the product infrastructure and is not intended to be used directly from your code.

Provides a standard FORMATETC structure that is logically equivalent to a more complex structure. Use this method to determine whether two different FORMATETC structures would return the same data, removing the need for duplicate rendering.

Namespace:   System.Windows.Forms
Assembly:  System.Windows.Forms (in System.Windows.Forms.dll)

[SecurityPermissionAttribute(SecurityAction.Demand, Flags = SecurityPermissionFlag.UnmanagedCode)]
int IDataObject.GetCanonicalFormatEtc(
	ref FORMATETC pformatetcIn,
	out FORMATETC pformatetcOut


Type: System.Runtime.InteropServices.ComTypes.FORMATETC

A pointer to a FORMATETC structure, passed by reference, that defines the format, medium, and target device that the caller would like to use to retrieve data in a subsequent call such as GetData. The TYMED member is not significant in this case and should be ignored.

Type: System.Runtime.InteropServices.ComTypes.FORMATETC

When this method returns, contains a pointer to a FORMATETC structure that contains the most general information possible for a specific rendering, making it canonically equivalent to formatetIn. The caller must allocate this structure and the GetCanonicalFormatEtc method must fill in the data. To retrieve data in a subsequent call such as GetData, the caller uses the supplied value of formatOut, unless the value supplied is null. This value is null if the method returns DATA_S_SAMEFORMATETC. The TYMED member is not significant in this case and should be ignored. This parameter is passed uninitialized.

Return Value

Type: System.Int32

This method supports the standard return values E_INVALIDARG, E_UNEXPECTED, and E_OUTOFMEMORY, as well as the following:




The returned FORMATETC structure is different from the one that was passed.


The FORMATETC structures are the same and null is returned in the formatOut parameter.


There is an invalid value for lindex; currently, only -1 is supported.


There is an invalid value for the pFormatetc parameter.


The application is not running.

This member is an explicit interface member implementation. It can be used only when the DataObject is cast to an IDataObject interface.


for calling unmanaged code. Associated enumeration: SecurityPermissionFlag.UnmanagedCode

.NET Framework
Available since 2.0
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