USBDeviceBeginControlOut Method (Byte, Byte, Int32, Int32, Byte, Int32, AsyncCallback, Object) |
Initiates an asynchronous control transfer over the default control endpoint. The request should have an OUT direction (specified by the highest bit
of the requestType parameter).
Namespace:
MadWizard.WinUSBNet
Assembly:
WinUSBNet (in WinUSBNet.dll) Version: 2.0.0.0 (2.0.0.0)
Syntax public IAsyncResult BeginControlOut(
byte requestType,
byte request,
int value,
int index,
byte[] buffer,
int length,
AsyncCallback userCallback,
Object stateObject
)
Public Function BeginControlOut (
requestType As Byte,
request As Byte,
value As Integer,
index As Integer,
buffer As Byte(),
length As Integer,
userCallback As AsyncCallback,
stateObject As Object
) As IAsyncResult
public:
IAsyncResult^ BeginControlOut(
unsigned char requestType,
unsigned char request,
int value,
int index,
array<unsigned char>^ buffer,
int length,
AsyncCallback^ userCallback,
Object^ stateObject
)
Parameters
- requestType
- Type: SystemByte
The setup packet request type. The request type must specify the OUT direction (highest bit cleared). - request
- Type: SystemByte
The setup packet device request. - value
- Type: SystemInt32
The value member in the setup packet. Its meaning depends on the request. Value should be between zero and 65535 (0xFFFF). - index
- Type: SystemInt32
The index member in the setup packet. Its meaning depends on the request. Index should be between zero and 65535 (0xFFFF). - buffer
- Type: SystemByte
The buffer that contains the data to be transfered. - length
- Type: SystemInt32
Length of the data to transfer. Must be equal to or less than the length of buffer. The setup packet's length member will be set to this length. - userCallback
- Type: SystemAsyncCallback
An optional asynchronous callback, to be called when the control transfer is complete. Can be null if no callback is required. - stateObject
- Type: SystemObject
A user-provided object that distinguishes this particular asynchronous operation. Can be null if not required.
Return Value
Type:
IAsyncResultAn
IAsyncResult object representing the asynchronous control transfer, which could still be pending.
Remarks This method always completes immediately even if the operation is still pending. The
IAsyncResult object returned represents the operation
and must be passed to
EndControlTransfer(IAsyncResult) to retrieve the result of the operation. For every call to this method a matching call to
EndControlTransfer(IAsyncResult) must be made. When
userCallback specifies a callback function, this function will be called when the operation is completed. The optional
stateObject parameter can be used to pass user-defined information to this callback or the
IAsyncResult. The
IAsyncResult
also provides an event handle (
AsyncWaitHandle) that will be triggered when the operation is complete as well.
See Also