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WsFlushBody function

Flushes all accumulated message body data that has been written.

When message uses WsWriteBody or XML Writer the data is accumulated in a buffer. WsFlushBody subsequently performs the actual I/O.

WsFlushBody is typically used when channel I/O is set to WS_STREAMED_OUTPUT_TRANSFER_MODE, or when using an XML Writer set to use WS_XML_WRITER_STREAM_OUTPUT.


  _In_     WS_MESSAGE*             message,
  _In_     ULONG                   minSize,
  _In_opt_ const WS_ASYNC_CONTEXT* asyncContext,
  _In_opt_ WS_ERROR*               error


message [in]

A pointer to the WS_MESSAGE structure containing the accumulated message body data.

minSize [in]

Specifies the minimum number of bytes that must be present in the message for the function to perform the data flush.

Note  If the message contains less than minSize WSFlushBody terminates without doing the I/O flush. A larger value will ensure that no I/O will be done until the larger value has been accumulated. This is useful for ensuring that larger chunks are used when doing I/O. And presuming that there is at least one byte of accumulated data a value of 0 in minSize guarantees that it will be flushed.
asyncContext [in, optional]

A pointer to a WS_ASYNC_CONTEXT data structure with information about invoking the function asynchronously. A NULL value indicates a request for synchronous operation.

error [in, optional]

A pointer to a WS_ERROR object where additional information about the error should be stored if the function fails.

Return value

This function can return one of these values.

Return codeDescription

The asynchronous operation is still pending.


The input data was not in the expected format or did not have the expected value.


One or more arguments are invalid.


Ran out of memory.

Other Errors

This function may return other errors not listed above.



This function is a "no-op" when WS_STREAMED_OUTPUT_TRANSFER_MODE is not set, or when using an XML Writer with WS_XML_WRITER_BUFFER_OUTPUT set.

This function is shortcut for calling WsFlushWriter for the XML Writer being used to write the message. Calling WsFlushWriter directly is equivalent to calling this function.


Minimum supported client

Windows 7 [desktop apps | Windows Store apps]

Minimum supported server

Windows Server 2008 R2 [desktop apps | Windows Store apps]









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