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我正在使用此代碼但不工作並拋出此異常:未將對象引用設置爲對象實例 devices [0]給出空值。用於字符寫入和讀取的UWP串行端口通信(UWP和Arduino)
private async void ConnectToSerialPort()
{
string selector = SerialDevice.GetDeviceSelector("COM7");
DeviceInformationCollection devices = await DeviceInformation.FindAllAsync(selector);
if (devices.Count > 0)
{
DeviceInformation deviceInfo = devices[0];
SerialDevice serialDevice = await SerialDevice.FromIdAsync(deviceInfo.Id);
Debug.WriteLine(serialDevice);
serialDevice.BaudRate = 9600;
serialDevice.DataBits = 8;
serialDevice.StopBits = SerialStopBitCount.Two;
serialDevice.Parity = SerialParity.None;
DataWriter dataWriter = new DataWriter(serialDevice.OutputStream);
dataWriter.WriteString("your message here");
await dataWriter.StoreAsync();
dataWriter.DetachStream();
dataWriter = null;
}
else
{
MessageDialog popup = new MessageDialog("Sorry, no device found.");
await popup.ShowAsync();
}
}
private void Button_Click(object sender, RoutedEventArgs e)
{
ConnectToSerialPort();
}
請幫我解決這個錯誤,我會非常感謝你。 請幫助:(
發生在 –
serialDevice哪行的例外呢?是給零例外... – Softdeveloper
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