程序包 ohos.usb

类 USBRequest

java.lang.Object

ohos.usb.USBRequest

public class USBRequest
extends Object

Implements bulk transfer of data and control messages between USB devices.

从以下版本开始:

5

SystemCapability

SystemCapability.Usb#USB_MANAGER

构造器概要

构造器

构造器	说明
USBRequest()

方法概要

限定符和类型	方法	说明
void	abort()	Aborts a pending queue operation.
void	dequeue(boolean useBufferOverflowInsteadOfIllegalArg)	Dequeues a request to send or receive data on its endpoint.
void	free()	Frees all resources related to this request.
Object	getClientData()	Gets client data of the USBRequst instance.
boolean	initialize(USBDevicePipe connection, USBEndpoint ep)	Initializes a specified endpoint for data transfer.
boolean	queue(ByteBuffer buffer)	Transfers data on the requested endpoint, and queues the request.
boolean	queue(ByteBuffer buffer, int length)	Transfers data on the requested endpoint, and queues the request.
void	setClientData(Object data)	Sets client data of the USBRequst instance.

从类继承的方法 java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

构造器详细资料

USBRequest

public USBRequest()

方法详细资料

abort

public void abort()

Aborts a pending queue operation.

free

public void free()

Frees all resources related to this request.

initialize

public boolean initialize(USBDevicePipe connection,
                          USBEndpoint ep)

Initializes a specified endpoint for data transfer.

参数:

connection - Indicates a USBDevicePipe instance.

ep - Indicates an instance of the USBEndpoint class.

返回:

Returns true if the initialization is successful; returns false otherwise.

从以下版本开始:

5

queue

public boolean queue(ByteBuffer buffer)

Transfers data on the requested endpoint, and queues the request.

参数:

buffer - Indicates the buffer from which data is to be transferred.

返回:

Returns true if the data transfer is successful; returns false otherwise.

从以下版本开始:

5

queue

public boolean queue(ByteBuffer buffer,
                     int length)

Transfers data on the requested endpoint, and queues the request.

参数:

buffer - Indicates the buffer from which data is to be transferred.

length - Indicates the length of buffer.

返回:

Returns true if the data transfer is successful; returns false otherwise.

从以下版本开始:

5

dequeue

public void dequeue(boolean useBufferOverflowInsteadOfIllegalArg)

Dequeues a request to send or receive data on its endpoint.

参数:

useBufferOverflowInsteadOfIllegalArg - Specifies whether to replace the illegal parameter with a buffer overflow.

从以下版本开始:

5

setClientData

public void setClientData(Object data)

Sets client data of the USBRequst instance.

参数:

data - The client data to be set.

从以下版本开始:

5

getClientData

public Object getClientData()

Gets client data of the USBRequst instance.

返回:

Returns the client data.

从以下版本开始:

5