UsbInterface 类

定义

public ref class UsbInterface sealed

/// [Windows.Foundation.Metadata.ContractVersion(Windows.Foundation.UniversalApiContract, 65536)]
/// [Windows.Foundation.Metadata.MarshalingBehavior(Windows.Foundation.Metadata.MarshalingType.Agile)]
class UsbInterface final

[Windows.Foundation.Metadata.ContractVersion(typeof(Windows.Foundation.UniversalApiContract), 65536)]
[Windows.Foundation.Metadata.MarshalingBehavior(Windows.Foundation.Metadata.MarshalingType.Agile)]
public sealed class UsbInterface

Public NotInheritable Class UsbInterface

继承

Object Platform::Object IInspectable UsbInterface

属性

ContractVersionAttribute MarshalingBehaviorAttribute

Windows 要求

示例

此代码示例演示如何分析描述符并获取管道对象。 该示例假定应用之前已获取 UsbDevice 对象。

using Windows.Devices.Usb;
using Windows.Storage.Streams;

protected override async void OnLaunched(LaunchActivatedEventArgs args)
{

    UsbDevice device;
    UInt32 readLen = 8;

    // Get the UsbDevice object. Not shown.

    ...

    UsbInterface myInterface = null;

    //
    // Need to find this descriptor after an interface descriptor:
    //
    //   ===>Class-Specific Video Control Interface Header Descriptor<===
    // bLength:   0x0D
    // bDescriptorType:   0x24
    // bDescriptorSubtype:0x01
    // bcdVDC:  0x0100
    // wTotalLength:    0x00D9  -> Validated
    // dwClockFreq: 0x02DC6C00 = (48000000) Hz
    // bInCollection:     0x01
    // baInterfaceNr[1]:  0x01
    // USB Video Class device: spec version 1.0
    //
    foreach (var interf in device.Configuration.UsbInterfaces)
    {
        foreach (var setting in interf.InterfaceSettings)
        {
            var descriptors = setting.Descriptors;

            // First descriptor in the setting must be the interface descriptor
            if (descriptors.Count >= 2 &&
                UsbInterfaceDescriptor.TryParse(descriptors[0], null) == 
                                            true && 
                                            descriptors[1].Length == 0x0D &&
                                            descriptors[1].DescriptorType == 0x24)
            {
                Windows.Storage.Streams.Buffer buffer = new Windows.Storage.Streams.Buffer(readLen);
                descriptors[1].readDescriptorBuffer(buffer);
                Windows.Storage.Streams.DataReader reader = Windows.Storage.Streams.DataReader.FromBuffer(buffer);

                reader.ReadByte(); // bLength
                reader.ReadByte(); // bDescriptorType
                byte bDescriptorSubType = reader.ReadByte();

                if (bDescriptorSubType == 0x01) 
                {
                    // This is our interface.
                    myInterface = interf;
                    ushort bcdVDC = reader.ReadUInt16();
                    ushort wTotalLength = reader.ReadUInt16();
                    byte lsb = reader.ReadByte();
                    uint dwClockFreq = (reader.ReadUInt16() << 8) + lsb;
                    byte bInCollection = reader.ReadByte();
                    byte baInterfaceNr1 = reader.ReadByte();

                    await setting.SelectSettingAsync();
                }
                break;
            }
        }

        if (myInterface != null)
        {
            break;
        }
    }

    if (myInterface == null)
    {
        ShowError("Video Control Interface descriptor not found");
        return;
    }

    // Pipes are now available to communicate with endpoints

    UsbInterruptInPipe interruptIn = myInterface.InterruptInPipes[0];
    UsbBulkOutPipe bulkOut = myInterface.BulkOutPipes[0];

}

属性

适用于