Why can only read 49 bytes of data every time read(), I pass the 256-length byte[] array, or can only read 49 bytes?

[a751116023]

为什么每次read()只能读取49个byte的数据，我传过去256长度的byte[]数组，还是只能读取到49个byte？ HID设备每次返回128个byte的数据，但是我只能接收到48个byte，造成接收数据混乱。。请问有方法避免这个问题吗？

[gary-rowe]

Google translate: Why can only read 49 bytes of data every time read(), I pass the 256-length byte[] array, or can only read 49 bytes? The HID device returns 128 bytes of data each time, but I can only receive 48 bytes, causing confusion in the received data. Is there a way to avoid this problem?

[gary-rowe]

Just using read() will use defaults of 64 bytes and a 100ms timeout. You might want to consider using read(128,200) for a more flexible approach.

In hid4java-v0.8.0 (not released yet but available on the develop branch) there is a readAll() method that will read all bytes coming from the device in a single hit.

Google translate: 仅使用read（）将使用64字节的默认值和100ms的超时时间。 您可能需要考虑使用read（128,200）获得更灵活的方法。

在v0.8.0（尚未发布，但可在develop分支上使用）中，有一个readAll（）方法将在一次命中中读取来自设备的所有字节。

[a751116023]

Is Hid4Java-0.7.0 using 0.7 or 0.8 hidAPI?

hid4java-0.7.0使用的hidapi是0.7还是0.8？

[gary-rowe]

Please translate your questions to English using Google Translate.

Google translate: 请使用[Google翻译]（https://translate.google.com）将您的问题翻译成英语。

[gary-rowe]

hid4java-0.7.0 uses hidapi-0.9.0. The release policy is to use the latest available release of hidapi at the time.

[a751116023]

English: According to the problems I encountered in actual use, more than one Hiddevice was found by SN using the same VID and PID. I've added a getHidDeviceList() method to the hidservices class that returns all of the List criteria. Then test the return value using the hiddevice.write () method, which if > 0 is the operable target device

Chinese: 根据我在实际使用中遇到的问题，使用相同的vid和pid, sn查找到的hiddevice不止一个。 我在hidservices类增加了getHidDeviceList()方法，该方法返回所有满足条件的List。 然后使用hidDevice.write()方法测试返回值,如果> 0,该hiddevice为可操作的目标设备