USB.requestDevice() - Web APIs 编辑

Experimental

This is an experimental technology
Check the Browser compatibility table carefully before using this in production.

Secure context

This feature is available only in secure contexts (HTTPS), in some or all supporting browsers.

The requestDevice() method of the USB interface returns a Promise that resolves with an instance of USBDevice if the specified device is found. Calling this function triggers the user agent's pairing flow.

Syntax

USB.requestDevice([filters])

Parameters

filters

An array of filter objects for possible devices you would like to pair. Each filter object can have the following properties:

• vendorId
• productId
• classCode
• subclassCode
• protocolCode
• serialNumber

Return value

A Promise that resolves with an instance of USBDevice.

Example

The following example looks for one of two USB devices. Notice that two product IDs are specified. Both are passed to requestDevice(). This triggers a user-agent flow that prompts the user to select a device for pairing. Only the selected device is passed to then().

The number of filters does not specifiy the number of devices shown by the user agent. For example, if only a USB device with product ID 0xa800 is found, then only one device will be listed by the user agent. On the other hand if the user agent finds two of the first listed device and one of the second, then all three devices will be listed.

const filters = [
        {vendorId: 0x1209, productId: 0xa800},
        {vendorId: 0x1209, productId: 0xa850}
      ];
navigator.usb.requestDevice({filters: filters})
.then(usbDevice => {
  console.log("Product name: " + usbDevice.productName);
})
.catch(e => {
  console.log("There is no device. " + e);
});

Specifications

Browser compatibility

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