以第二种形式使用SerialPort

Question

I am trying to write to a .xml file and am getting the error Object reference not set to an instance of an object. on line 49 (CreateNode) . This is the code that I have tried, but no luck.

private void CreateNode(string Port, string BaudRate, string DataBits, string Parity,_
string StopBits, string Handshaking, XmlTextWriter writer)
{
    //Writing to the .xml file. This will make the program be able to load the properties last used.
    writer.WriteStartElement("ApplicationProperties");
    writer.WriteStartElement("Port");
    writer.WriteString(Port);
    writer.WriteEndElement();
    writer.WriteStartElement("BaudRate");
    writer.WriteString(BaudRate);
    writer.WriteEndElement();
    writer.WriteStartElement("DataBits");
    writer.WriteString(DataBits);
    writer.WriteEndElement();
    writer.WriteStartElement("Parity");
    writer.WriteString(Parity);
    writer.WriteEndElement();
    writer.WriteStartElement("StopBits");
    writer.WriteString(StopBits);
    writer.WriteEndElement();
    writer.WriteStartElement("Handshaking");
    writer.WriteString(Handshaking);
    writer.WriteEndElement();
    writer.WriteEndElement();
}

private void SaveProperties()
{
    //CreateNode(everything being referenced. Put text boxes, and drop down boxes here.
    XmlTextWriter writer = new XmlTextWriter(@"C:\ForteSenderv2.0\Properties.xml", System.Text.Encoding.UTF8);
    writer.WriteStartDocument(true);

    //Making the code indeted by 2 characters.
    writer.Formatting = Formatting.Indented;
    writer.Indentation = 2;

    //Making the start element "Table".
    writer.WriteStartElement("Forte_Data_Gatherer_Application");
    //Calling the rst of the .xml file to write.
    CreateNode(ApplicationPort.PortName, ApplicationPort.BaudRate.ToString(), ApplicationPort.DataBits.ToString(), ApplicationPort.Parity.ToString(), ApplicationPort.StopBits.ToString(), ApplicationPort.Handshake.ToString(), writer);
    writer.WriteEndElement();
    writer.WriteEndDocument();
    writer.Close();
}

Answer 1

Dim mySerialPort as serialPort

mySerialPort.PortName = SetPortName(mySerialPort.ApplicationPort);

MSDN is a great resource .

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Edit

error: Object reference not set to an instance of an object. on line 49 (CreateNode).

private void CreateNode(string Port, string BaudRate, string DataBits, string Parity,_
string StopBits, string Handshaking, XmlTextWriter writer)

private void blabla (PortName as string, BaudRate as string, DataBits as string,_
Parity as string, Handshaking as string)

I cannot see how you would have XmlTextwriter in there. Personally, I have not seen anything quite like this.. I can see your efforts and really appreciate your work and what you are trying to achieve, I truly think you are overcomplicating things. The trick with coding (not that I am an expert), is to go for the simplest way to create the functionality you require. As short as possible, as long as necessary.

I think you need to rethink your algorithm of what you are trying to achieve, Am I going about this in the simplest way or am I making unnecessary complications to this project?

When creating subs, functions , etc, you don't need to stuff all the variables into the declaration at the top. That is what the body is for.

I urge you to use the MSDN and study this a little more, and it will get easier. Here is a link to the MSDN .Net Framework Class Library - it covers EVERYTHING :)