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二次开发时在hid_write函数处出错，之前没有错误不知道动了什么导致出错了，环境为X64的C++，使用下载的GUI软件是可以连接并投影图片的。
错误信息如下图
有可能是DeviceHandle没有成功打开。端口占用或者超出范围。
int HID_API_EXPORT HID_API_CALL hid_write(hid_device *dev, const unsigned char *data, size_t length)
{
DWORD bytes_written;
BOOL res;
OVERLAPPED ol;
unsigned char *buf;
memset(&ol, 0, sizeof(ol));
/* Make sure the right number of bytes are passed to WriteFile. Windows
expects the number of bytes which are in the _longest_ report (plus
one for the report number) bytes even if the data is a report
which is shorter than that. Windows gives us this value in
caps.OutputReportByteLength. If a user passes in fewer bytes than this,
create a temporary buffer which is the proper size. */
if (length >= dev->output_report_length) {
/* The user passed the right number of bytes. Use the buffer as-is. */
buf = (unsigned char *) data;
} else {
/* Create a temporary buffer and copy the user's data
into it, padding the rest with zeros. */
buf = (unsigned char *) malloc(dev->output_report_length);
memcpy(buf, data, length);
memset(buf + length, 0, dev->output_report_length - length);
length = dev->output_report_length;
}
res = WriteFile(dev->device_handle, buf, length, NULL, &ol);
if (!res) {
if (GetLastError() != ERROR_IO_PENDING) {
/* WriteFile() failed. Return error. */
register_error(dev, "WriteFile");
bytes_written = -1;
goto end_of_function;
/* Wait here until the write is done. This makes
hid_write() synchronous. */
res = GetOverlappedResult(dev->device_handle, &ol, &bytes_written, TRUE/*wait*/);
/* The Write operation failed. */
end_of_function:
if (buf != data)
free(buf);
return bytes_written;
