C# Read XML - Need help please!

[Guest]

Hi there,

I have some problems when reading XML file.

1. First this, is what i did, cause i can't seem to read "sub elements or
tags" values, so i place those values into attributes like this.

Before:
----------

<?xml version="1.0" encoding="utf-8"?>
<MyConfig>
<Device Type="A1">
<Open />
<EstablishDevice>
<DeviceName>Titan 12</DeviceName>
<DeviceLength>8</DeviceLength>
</EstablishDevice>
<Reset>
<Slot>0</Slot>
</Reset>
</Device>
<Device Type="A2">
<EstablishDevice>
<DeviceName>Titan 13</DeviceName>
<DeviceLength>8</DeviceLength>
</EstablishDevice>
<Reset>
<Slot>1</Slot>
</Device>
</MyConfig>

After:
--------

<?xml version="1.0" encoding="utf-8"?>
<MyConfig>
<Device Type="A1">
<Open />
<EstablishDevice Name="Titan 12" Length="8" />
<Reset Slot="0" />
</Device>
<Device Type="A2">
<Open />
<EstablishDevice Name="Titan 13" Length="8" />
<Reset Slot="1" />
</Device>
</MyConfig>

So this is how my C# codes look like (but i think it is quite of wrong!)

C# - Read XML Tag + Attributes + Processing:
------------------------------------------------------

// strpath is the location of the xml file
XmlTextReader xmlreader = new XmlTextReader(strPath);

// Create instance of MyLibrary
_library = new MyLibrary();

string sName = string.Empty;

while (xmlreader.Read())
{
switch (xmlreader.NodeType)
{
case XmlNodeType.Element:
//
//sName = xmlreader.Name;
if (xmlreader.Name.Equals("Device"))
{
lstResult.Items.Add("Type of Reader: " +
xmlreader.GetAttribute("Type"));
lstResult.Items.Add("Build in progress ...");
}


if (xmlreader.Name.Equals("Open"))
{
try
{
// MyLibrary Open Method
_library.Open();
lstResult.Items.Add("OpenDevice is success");
}
catch (Exception e)
{
lstResult.Items.Add("Open is not success" + re.Message);
}
}

if (xmlreader.Name.Equals("EstablishDevice"))
{
string deviceName = xmlreader.GetAttribute("Name");
int deviceLength = Int32.Parse(xmlreader.GetAttribute("Length"));

try
{
// Establish hardware connection
_library.EstablishDevice(deviceName, deviceLength);
lstResult.Items.Add("EstablishDevice " +
xmlreader.GetAttribute("Name") + " " + xmlreader.GetAttribute("Length") + "
is successfull!");
}
catch (Exception e)
{
lstResult.Items.Add("Error: " + e.Message);
}
}

if (xmlreader.Name.Equals("Reset"))
{
short slotNumber = Int16.Parse(xmlreader.GetAttribute("Slot"));

try
{
// Reset the hardware before used
_library.Reset(slotNumber);
lstResult.Items.Add("Reset Device at Slot " +
xmlreader.GetAttribute("Slot") + " is successfull!");
}
catch (Exception e)
{
lstResult.Items.Add("Error: " + e.Message);
}
}
break;
}
}
}

I really felt weird with the way i do. Is XPath a better technique to get
values directly? Just say, if i have 1000 lines of xml code, it is going to
read line by line even it does not use it. You get my meaning!

Now is my problem. I want to test my data which looks like below (just want
to avoid attributes for a while).

Assuming:

.....
.....
<Reset Slot="1" />
<!-- Add-on -->
</Device>
<Command id="A001">
<Slot Type="0">
<DataIn>12345678</DataIn>
<DataOut />
</Slot>
</Command>
<Command id="A002">
<Slot Type="0">
<DataIn />
<!-- Expect data out to be written here -->
<DataOut></DataOut>
</Slot>
</Command>
....
....
</MyConfig>

So now how do i read those values from DataIn?

I need to place some identification at Command, so i can know which command
tag to write the dataout.

Any help please? I hope you understand what is the problem here. If you
think there is a better way, please let me know!

Thanks.

 

[Dennis Myrén]

I would recommend using DOM(XmlDocument) if the document is not huge.
Because it is easier, especially in this context of reading special nodes.
XmlDocument doc = new XmlDocument();
doc.Load(strPath);
To get the first "DataIn" element:
// ASSUMING "Command" is direct descendant of root.
XmlNode node =
doc.DocumentElement.SelectSingleNode("Command[@id='A001']/Slot/DataIn");
Console.WriteLine(node.InnerText);

If you need more help, please explain exactly what you are trying to do.