IHttpSysRequestPropertyFeature.TryGetRequestProperty Method
Definition
Important
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Reads an arbitrary HTTP_REQUEST_PROPERTY value from HTTP.SYS using the HttpQueryRequestProperty Windows API.
public virtual bool TryGetRequestProperty(int propertyId, ReadOnlySpan<byte> qualifier, Span<byte> output, out int bytesReturned);abstract member TryGetRequestProperty : int * ReadOnlySpan<byte> * Span<byte> * int -> bool
override this.TryGetRequestProperty : int * ReadOnlySpan<byte> * Span<byte> * int -> boolPublic Overridable Function TryGetRequestProperty (propertyId As Integer, qualifier As ReadOnlySpan(Of Byte), output As Span(Of Byte), ByRef bytesReturned As Integer) As BooleanParameters
- propertyId
- Int32
The HTTP_REQUEST_PROPERTY identifier to query. The set of supported values is defined by the
HTTP_REQUEST_PROPERTY enum in http.h; the caller is responsible for parsing the bytes returned in
output using the corresponding native struct.
- qualifier
- ReadOnlySpan<Byte>
Optional property-specific qualifier bytes. Pass an empty span for properties that do not require a qualifier; it will be mapped to a null pointer when calling the underlying API.
Destination buffer that receives the property value. Pass an empty span to query the required buffer size via bytesReturned.
- bytesReturned
- Int32
Returns the number of bytes written to output.
If output was too small (or empty), returns the size of the buffer required to hold the value.
Returns
True if the property was successfully read into output.
False if output is not large enough to hold the value; in that case bytesReturned
contains the required buffer size.
For any other failure, an exception is thrown.
Exceptions
Any HttpSys error except for ERROR_INSUFFICIENT_BUFFER or ERROR_MORE_DATA.
If the installed Windows HTTP Server API does not support HttpQueryRequestProperty.
Remarks
If the required buffer size is not known up front, first call this method with an empty output to retrieve the required size in bytesReturned, then allocate that many bytes and retry the query.