未验证 提交 9ae1fe38 编写于 作者: 葛亚芳 提交者: Gitee

update en/application-dev/device/usb-guidelines.md:改为纯净markdown并添加API参考链接,无需翻译

Signed-off-by: N@ge-yafang <geyafang@huawei.com>
上级 c97a9d82
# USB Service Development<a name="EN-US_TOPIC_0000001177435986"></a>
# USB Service Development
## When to Use<a name="section312612461984"></a>
## When to Use
In Host mode, you can obtain the list of connected devices, enable or disable the devices, manage device access permissions, and perform data transfer or control transfer.
## APIs<a name="section912mcpsimp"></a>
## APIs
The USB service provides the following functions: query of USB device list, bulk data transfer, control transfer, and access permission management.
The following table lists the USB APIs currently available. For details, see the _API Reference_.
The following table lists the USB APIs currently available. For details, see the [API Reference](../reference/apis/js-apis-usb.md).
**Table 1** Open USB APIs
<a name="table948mcpsimp"></a>
<table><thead align="left"><tr id="row954mcpsimp"><th class="cellrowborder" valign="top" width="58.589999999999996%" id="mcps1.2.3.1.1"><p id="p956mcpsimp"><a name="p956mcpsimp"></a><a name="p956mcpsimp"></a>API</p>
</th>
<th class="cellrowborder" valign="top" width="41.410000000000004%" id="mcps1.2.3.1.2"><p id="p958mcpsimp"><a name="p958mcpsimp"></a><a name="p958mcpsimp"></a>Description</p>
</th>
</tr>
</thead>
<tbody><tr id="row960mcpsimp"><td class="cellrowborder" valign="top" width="58.589999999999996%" headers="mcps1.2.3.1.1 "><p id="p763891054416"><a name="p763891054416"></a><a name="p763891054416"></a>hasRight(deviceName: string): boolean</p>
</td>
<td class="cellrowborder" valign="top" width="41.410000000000004%" headers="mcps1.2.3.1.2 "><p id="p8666818458"><a name="p8666818458"></a><a name="p8666818458"></a>Checks whether the user, for example, the application or system, has the device access permissions. The value <strong id="b106930333555"><a name="b106930333555"></a><a name="b106930333555"></a>true</strong> is returned if the user has the device access permissions; the value <strong id="b72426431937"><a name="b72426431937"></a><a name="b72426431937"></a>false</strong> is returned otherwise.</p>
</td>
</tr>
<tr id="row965mcpsimp"><td class="cellrowborder" valign="top" width="58.589999999999996%" headers="mcps1.2.3.1.1 "><p id="p1063810103448"><a name="p1063810103448"></a><a name="p1063810103448"></a>requestRight(deviceName: string): Promise&lt;boolean&gt;</p>
</td>
<td class="cellrowborder" valign="top" width="41.410000000000004%" headers="mcps1.2.3.1.2 "><p id="p18677811454"><a name="p18677811454"></a><a name="p18677811454"></a>Requests the temporary permission for a given application to access the USB device.</p>
</td>
</tr>
<tr id="row970mcpsimp"><td class="cellrowborder" valign="top" width="58.589999999999996%" headers="mcps1.2.3.1.1 "><p id="p196381710194415"><a name="p196381710194415"></a><a name="p196381710194415"></a>connectDevice(device: USBDevice): Readonly&lt;USBDevicePipe&gt;</p>
</td>
<td class="cellrowborder" valign="top" width="41.410000000000004%" headers="mcps1.2.3.1.2 "><p id="p467178204510"><a name="p467178204510"></a><a name="p467178204510"></a>Connects to the USB device based on the device information returned by <strong id="b191413527412"><a name="b191413527412"></a><a name="b191413527412"></a>getDevices()</strong>.</p>
</td>
</tr>
<tr id="row975mcpsimp"><td class="cellrowborder" valign="top" width="58.589999999999996%" headers="mcps1.2.3.1.1 "><p id="p8638171010441"><a name="p8638171010441"></a><a name="p8638171010441"></a>getDevices(): Array&lt;Readonly&lt;USBDevice&gt;&gt;</p>
</td>
<td class="cellrowborder" valign="top" width="41.410000000000004%" headers="mcps1.2.3.1.2 "><p id="p176715864514"><a name="p176715864514"></a><a name="p176715864514"></a>Obtains the USB device list.</p>
</td>
</tr>
<tr id="row1551153313610"><td class="cellrowborder" valign="top" width="58.589999999999996%" headers="mcps1.2.3.1.1 "><p id="p156381410184417"><a name="p156381410184417"></a><a name="p156381410184417"></a>setConfiguration(pipe: USBDevicePipe, config: USBConfig): number</p>
</td>
<td class="cellrowborder" valign="top" width="41.410000000000004%" headers="mcps1.2.3.1.2 "><p id="p126812817456"><a name="p126812817456"></a><a name="p126812817456"></a>Sets the USB device configuration.</p>
</td>
</tr>
<tr id="row1393711361263"><td class="cellrowborder" valign="top" width="58.589999999999996%" headers="mcps1.2.3.1.1 "><p id="p1563812109442"><a name="p1563812109442"></a><a name="p1563812109442"></a>setInterface(pipe: USBDevicePipe, iface: USBInterface): number</p>
</td>
<td class="cellrowborder" valign="top" width="41.410000000000004%" headers="mcps1.2.3.1.2 "><p id="p136868164513"><a name="p136868164513"></a><a name="p136868164513"></a>Sets a USB interface.</p>
</td>
</tr>
<tr id="row149651544154717"><td class="cellrowborder" valign="top" width="58.589999999999996%" headers="mcps1.2.3.1.1 "><p id="p991359174910"><a name="p991359174910"></a><a name="p991359174910"></a>claimInterface(pipe: USBDevicePipe, iface: USBInterface, force?: boolean): number</p>
</td>
<td class="cellrowborder" valign="top" width="41.410000000000004%" headers="mcps1.2.3.1.2 "><p id="p20859028134917"><a name="p20859028134917"></a><a name="p20859028134917"></a>Claims a USB interface</p>
</td>
</tr>
<tr id="row115717481477"><td class="cellrowborder" valign="top" width="58.589999999999996%" headers="mcps1.2.3.1.1 "><p id="p17913393493"><a name="p17913393493"></a><a name="p17913393493"></a>function bulkTransfer(pipe: USBDevicePipe, endpoint: USBEndpoint, buffer: Uint8Array, timeout?: number): Promise&lt;number&gt;</p>
</td>
<td class="cellrowborder" valign="top" width="41.410000000000004%" headers="mcps1.2.3.1.2 "><p id="p1786016281498"><a name="p1786016281498"></a><a name="p1786016281498"></a>Performs bulk transfer.</p>
</td>
</tr>
<tr id="row1042013527474"><td class="cellrowborder" valign="top" width="58.589999999999996%" headers="mcps1.2.3.1.1 "><p id="p19913596492"><a name="p19913596492"></a><a name="p19913596492"></a>closePipe(pipe: USBDevicePipe): number</p>
</td>
<td class="cellrowborder" valign="top" width="41.410000000000004%" headers="mcps1.2.3.1.2 "><p id="p686013285492"><a name="p686013285492"></a><a name="p686013285492"></a>Closes a USB device pipe.</p>
</td>
</tr>
<tr id="row954011574471"><td class="cellrowborder" valign="top" width="58.589999999999996%" headers="mcps1.2.3.1.1 "><p id="p491315910499"><a name="p491315910499"></a><a name="p491315910499"></a>releaseInterface(pipe: USBDevicePipe, iface: USBInterface): number</p>
</td>
<td class="cellrowborder" valign="top" width="41.410000000000004%" headers="mcps1.2.3.1.2 "><p id="p14860202813493"><a name="p14860202813493"></a><a name="p14860202813493"></a>Releases a USB interface.</p>
</td>
</tr>
<tr id="row1475577184811"><td class="cellrowborder" valign="top" width="58.589999999999996%" headers="mcps1.2.3.1.1 "><p id="p69131096493"><a name="p69131096493"></a><a name="p69131096493"></a>getFileDescriptor(pipe: USBDevicePipe): number</p>
</td>
<td class="cellrowborder" valign="top" width="41.410000000000004%" headers="mcps1.2.3.1.2 "><p id="p16860202864913"><a name="p16860202864913"></a><a name="p16860202864913"></a>Obtains the file descriptor.</p>
</td>
</tr>
<tr id="row074819259481"><td class="cellrowborder" valign="top" width="58.589999999999996%" headers="mcps1.2.3.1.1 "><p id="p891416916496"><a name="p891416916496"></a><a name="p891416916496"></a>getRawDescriptor(pipe: USBDevicePipe): Uint8Array</p>
</td>
<td class="cellrowborder" valign="top" width="41.410000000000004%" headers="mcps1.2.3.1.2 "><p id="p486042804917"><a name="p486042804917"></a><a name="p486042804917"></a>Obtains the raw USB descriptor.</p>
</td>
</tr>
<tr id="row1557362913482"><td class="cellrowborder" valign="top" width="58.589999999999996%" headers="mcps1.2.3.1.1 "><p id="p129141944919"><a name="p129141944919"></a><a name="p129141944919"></a>controlTransfer(pipe: USBDevicePipe, contrlparam: USBControlParams, timeout?: number): Promise&lt;number&gt;</p>
</td>
<td class="cellrowborder" valign="top" width="41.410000000000004%" headers="mcps1.2.3.1.2 "><p id="p78605286493"><a name="p78605286493"></a><a name="p78605286493"></a>Performs control transfer.</p>
</td>
</tr>
</tbody>
</table>
## How to Develop<a name="section980mcpsimp"></a>
| API | Description |
| ------------------------------------------------------------ | ------------------------------------------------------------ |
| hasRight(deviceName: string): boolean | Checks whether the user, for example, the application or system, has the device access permissions. The value **true** is returned if the user has the device access permissions; the value **false** is returned otherwise. |
| requestRight(deviceName: string): Promise\<boolean> | Requests the temporary permission for a given application to access the USB device. |
| connectDevice(device: USBDevice): Readonly\<USBDevicePipe> | Connects to the USB device based on the device information returned by **getDevices()**. |
| getDevices(): Array<Readonly\<USBDevice>> | Obtains the USB device list. |
| setConfiguration(pipe: USBDevicePipe, config: USBConfig): number | Sets the USB device configuration. |
| setInterface(pipe: USBDevicePipe, iface: USBInterface): number | Sets a USB interface. |
| claimInterface(pipe: USBDevicePipe, iface: USBInterface, force?: boolean): number | Claims a USB interface |
| function bulkTransfer(pipe: USBDevicePipe, endpoint: USBEndpoint, buffer: Uint8Array, timeout?: number): Promise\<number> | Performs bulk transfer. |
| closePipe(pipe: USBDevicePipe): number | Closes a USB device pipe. |
| releaseInterface(pipe: USBDevicePipe, iface: USBInterface): number | Releases a USB interface. |
| getFileDescriptor(pipe: USBDevicePipe): number | Obtains the file descriptor. |
| getRawDescriptor(pipe: USBDevicePipe): Uint8Array | Obtains the raw USB descriptor. |
| controlTransfer(pipe: USBDevicePipe, contrlparam: USBControlParams, timeout?: number): Promise\<number> | Performs control transfer. |
## How to Develop
You can set a USB device as a host to connect to a device for data transfer. The development procedure is as follows:
......@@ -211,6 +152,4 @@ You can set a USB device as a host to connect to a device for data transfer. The
```js
usb.releaseInterface(pipe, interface);
usb.closePipe(pipe);
```
```
\ No newline at end of file
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