I have an XML file formatted like this:
<?xml version="1.0" encoding="utf-8"?>
<Snippets>
<Snippet name="abc">
<SnippetCode>
testcode1
</SnippetCode>
</Snippet>
<Snippet name="xyz">
<SnippetCode>
testcode2
</SnippetCode>
</Snippet>
...
</Snippets>
I have populated a listbox with the snippet name, and it works fine so far. For example (I haven't added any real snippets yet btw), my listbox contains:
abc
xyz
123
When I click on an item in the listbox, I want the snippet code of that item to be inserted into a textbox. Like if abc was clicked, testcode1 should be inserted into the textbox. I used this code on the double click event:
XDocument doc = XDocument.Load(Application.StartupPath + "\\Snippets.xml");
foreach (XElement xe in doc.Elements("Snippets").Elements("Snippet"))
{
if (listBox1.SelectedItem == xe.Attribute("name"))
{
textbox1.Text = xe.Element("SnippetCode").Value;
}
}
However, nothing gets inserted because it never finds the snippet code value. I added a MessageBox.Show("test"); inside the if statement to check if it executes but it never does. The selected listbox item name and snippetname have the same text, so it's quite strange it isn't ever executing.
Does anyone know what's wrong with my code? Also, does anyone know of a better idea to insert text in the document from the snippet element? This method isn't probably good as performance might be a problem for large XML files.
You're comparing the attribute itself with the value, instead of the attribute's value.
Additionally, I can't remember offhand what the type of ListBox.SelectedItem is, but if it's object then that will be doing a reference comparison instead of equality.
string selected = (string) listBox1.SelectedItem;
XDocument doc = XDocument.Load(Application.StartupPath + "\\Snippets.xml");
foreach (XElement xe in doc.Elements("Snippets").Elements("Snippet"))
{
if (xe.Attribute("name").Value == selected)
{
textbox1.Text = xe.Element("SnippetCode").Value;
}
}
Note that this will fail with an exception if there are any snippets without a "name" attribute. That's probably a good thing if every snippet is meant to have a name attribute - but if they're allowed not to, then using the explicit string conversion instead of the Value property is simple:
string selected = (string) listBox1.SelectedItem;
XDocument doc = XDocument.Load(Application.StartupPath + "\\Snippets.xml");
foreach (XElement xe in doc.Elements("Snippets").Elements("Snippet"))
{
if ((string) xe.Attribute("name") == selected)
{
textbox1.Text = xe.Element("SnippetCode").Value;
}
}
Note that you can also do this through LINQ:
string selected = (string) listBox1.SelectedItem;
XDocument doc = XDocument.Load(Application.StartupPath + "\\Snippets.xml");
string code = doc.Elements("Snippets")
.Elements("Snippet")
.Where(x => x.Attribute("name").Value == selected)
.Select(x => x.Element("SnippetCode").Value)
.FirstOrDefault();
if (code != null)
{
textbox1.Text = code;
}
I figured out the problem, xe.Attribute("name") was returning name="abc" instead of just abc. My bad for not realzing this just after making the above post.
Related
In C# I'm using the following to get some elements from an XML file:
var TestCaseDescriptions = doc.SelectNodes("//testcase/htmlcomment");
This works fine and gets the correct information but when my testcase has no htmlcomment it won't add any entry in the XmlNodeList TestCaseDescriptions.
When there's not htmlcomment I would like to have the value "null" as string the TestCaseDescriptions. So in the end I would have an XMLNodeList like
htmlcomment
htmlcomment
null
htmlcomment
htmlcomment
Can anyone describe or create a sample how to make this happen?
var TestCaseDescriptions = doc.SelectNodes("//testcase/htmlcomment");
When there's not htmlcomment I would like to have the value "null" as string the TestCaseDescriptions.
Your problem comes from the fact that if there is no htmlcomment, the number of selected nodes will be one less. The current answer shows what to do when the htmlcomment element is present, but empty, but I think you need this instead, if indeed the whole htmlcomment element is empty:
var testCases = doc.SelectNodes("//testcase");
foreach (XmlElement element in testCases)
{
var description = element.SelectSingleNode("child::htmlcomment");
string results = description == null ? "null" : description.Value;
}
In above code, you go over each test case, and select the child node htmlcomment of the test case. If not found, SelectSingleNode returns null, so the last line checks for the result and returns "null" in that case, or the node's value otherwise.
To change this result into a node, you will have to create the node as a child to the current node. You said you want an XmlNodeList, so perhaps this works for you:
var testCaseDescriptions = doc.SelectNodes("//testcase");
foreach (XmlElement element in testCaseDescriptions)
{
var comment = element.SelectSingleNode("child::htmlcomment");
if (comment == null)
{
element.AppendChild(
doc.CreateElement("htmlcomment")
.AppendChild(doc.CreateTextNode("none")));
}
}
After this, the node set is updated.
Note: apparently, the OP mentions that element.SelectSingleNode("child::htmlcomment"); does not work, but element.SelectSingleNode("./htmlcomment"); does, even though technically, these are equal expressions from the point of XPath, and should work according to Microsoft's documentation.
Try this
XmlDocument doc = new XmlDocument();
var TestCaseDescriptions = doc.SelectNodes("//testcase/htmlcomment");
foreach (XmlElement element in TestCaseDescriptions)
{
string results = element.Value == null ? "" : element.Value;
}
I have to extract values belonging to certain elements in an XML file and this is what I ended up with.
XDocument doc = XDocument.Load("request.xml");
var year = (string)doc.Descendants("year").FirstOrDefault();
var id = (string)doc.Descendants("id").FirstOrDefault();
I'm guessing that for each statement I'm iterating through the entire file looking for the first occurrence of the element called year/id. Is this the correct way to do this? It seems like there has to be a way where one would avoid unnecessary iterations. I know what I'm looking for and I know that the elements are going to be there even if the values may be null.
I'm thinking in the lines of a select statement with both "year" and "id" as conditions.
For clearance, I'm looking for certain elements and their respective values. There'll most likely be multiple occurrences of the same element but FirstOrDefault() is fine for that.
Further clarification:
As requested by the legend Jon Skeet, I'll try to clarify further. The XML document contains fields such as <year>2015</year> and <id>123032</id> and I need the values. I know which elements I'm looking for, and that they're going to be there. In the sample XML below, I would like to get 2015, The Emperor, something and 30.
Sample XML:
<?xml version="1.0" encoding="UTF-8"?>
<documents xmlns:xsd="http://www.w3.org/2001/XMLSchema" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance">
<make>Apple</make>
<year>2015</year>
<customer>
<name>The Emperor</name>
<level2>
<information>something</information>
</level2>
<age>30</age>
</customer>
A code that doesn't parse the whole xml twice would be like:
XDocument doc = XDocument.Load("request.xml");
string year = null;
string id = null;
bool yearFound = false, idFound = false;
foreach (XElement ele in doc.Descendants())
{
if (!yearFound && ele.Name == "year")
{
year = (string)ele;
yearFound = true;
}
else if (!idFound && ele.Name == "id")
{
id = (string)ele;
idFound = true;
}
if (yearFound && idFound)
{
break;
}
}
As you can see you are trading lines of code for speed :-) I do feel the code is still quite readable.
if you really need to optimize up to the last line of code, you could put the names of the elements in two variables (because otherwise there will be many temporary XName creation)
// before the foreach
XName yearName = "year";
XName idName = "id";
and then
if (!yearFound && ele.Name == yearName)
...
if (!idFound && ele.Name == idName)
I know basic about getting node values from a xml file, but in a complicated xaml file I don't know how to write my linq query.
This is a sample of xaml I'm using:
<Activity something:something = " 2010" x:class = "example"..........>
<x:Members>
<x:Property Name= "aaaaa" Type = "Inargument" />
</x:Members>
<sap:abcdef>1322,2222</sap:abcdef>
<prwab:work sap2010:Annotation.AnnotationText = " I need this value" Active = "False" CreatedOn = "2014-07-09" ID = "123456" DisplayName = "theNameIneed">
<prwab:work.activity>
<prwais:collectingActivity sap2010:Annotation.AnnotationText = "I also need this value" > CreatedOn = "2014-07-09" ID = "1234232" DisplayName = "Ineed2">
<prwais .....>
</prwais>
</prwis:collectingActivity>
</prwab:work.activity>
</prwab:work>
</Activity>
I need to get the data in the lines that contain attribute "sap2010:Annotation.AnnotationText", and the value is going to be the content of sap2010:Annotation.AnnotationText, and key is going to be the attribute "ID" and attribute "displayName" in that line.
Here is the query I have right now, I know it's wrong but I don't know the proper way to write it:
var dataNodes = XElement.Load(file, LoadOptions.None);
Console.WriteLine("Loaded xaml file: " + file);
var dataNodesDictionary = from dataRecord in (dataNodes.Elements("prwab") && dataNodes.Elements("prwais"))//this line is wrong, but I dont know how to write it, since annotation may appears in different elements, and even if I only use "prwab" for testing, i still get nothing
where dataRecord.Attributes("Annotation.AnnotationText") != null
select new DictionaryEntry
{
Key = dataRecord.Attribute("DisplayName").Value.ToString() + "|" + dataRecord.Attribute("ID").Value.ToString(),
Value = dataRecord.Attribute("Annotation.AnnotationText").Value.ToString(),
};
Can some one help me please, thanks.
First find all elements that have the attribute. Then pull the attribute values.
// Name of the attributes we are looking
string ns = "http://schemas.microsoft.com/netfx/2010/xaml/activities/presentation";
XName name = XName.Get("Annotation.AnnotationText", ns);
XDocument doc = XDocument.Load("XMLFile1.xml");
var q = doc.Descendants().Where(e => e.Attribute(name) != null)
.Select(e => new DictionaryEntry { Key = e.Attribute("ID").Value, Value = e.Attribute(name).Value });
SIDE NOTE: In the future please paste in valid XML so it is easier for others to reproduce the issue.
Since this is XAML, you'll have a problem:
The attribute you're looking for can be written using a tag:
<prwab:work sap2010:Annotation.AnnotationText="I need this value">
...
</prwab:work>
This is equivalent to:
<prwab:work>
<sap2010:Annotation.AnnotationText>
I need this value
</sap2010:Annotation.AnnotationText>
...
</prwab:work>
So if you need a reliable way to read that, you should use the XamlReader class (the one from the System.Xaml namespace - not the one from System.Windows.Markup). It works in a similar way to XmlReader, but normalizes the XAML it presents to you.
It won't be as straightforward as a linq query, but will be more reliable.
everyone!
I have an XML file and need to change the value of a node, specifically the indicated line. The problem i have is that as you can see, there are many nodes.
How can i change this line? This XML file could be much larger, so i am looking for a solution that would take different amounts of 'launch.file' nodes into account.
The node that will need to be set to True will be identified by the corresponding NAME tag. So if i typed in ULTII, the DISABLED node for that block will be set to True. If i typed in Catl, then the DISABLED node for that block would be changed.
<?xml version="1.0" encoding="windows-1252"?>
<SBase.Doc Type="Launch" version="1,0">
<Descr>Launch</Descr>
<Filename>run.xml</Filename>
<Disabled>False</Disabled>
<Launch.ManualLoad>False</Launch.ManualLoad>
<Launch.File>
<Name>Catl</Name>
<Disabled>False</Disabled>
<ManualLoad>False</ManualLoad>
<Path>ft\catl\catl.exe</Path>
</Launch.File>
<Launch.File>
<Disabled>False</Disabled> <!-- change to True -->
<ManualLoad>False</ManualLoad>
<Name>ULTII</Name>
<Path>F:\ULTII.exe</Path>
<NewConsole>True</NewConsole>
</Launch.File>
<Launch.File>
<Name>ECA</Name>
<Disabled>False</Disabled>
<Path>C:\ECA.exe</Path>
</Launch.File>
</SBase.Doc>
I am using Visual Studio 2012, should you need to know.
Thank you to anyone who can help me out on this, i really appreciate it.
Heres my method to do what you want
private void DisableLaunchFile(string xmlfile, string launchFileName){
XDocument doc = XDocument.Load(xmlfile);
var launchFileElement = doc.Descendants("Launch.File").Where (d => d.Element("Name").Value == lauchFileName);
launchFileElement.Elements("Disabled").First().Value = true.ToString();
doc.Save(xmlfile);
}
Use it like:
string pathToXmlFile = //assign ;
DisableLaunchFile(pathToXmlFile, "Catl");
DisableLaunchFile(pathToXmlFile, "ULTII");
This can be achieved by using LINQ to XML (see XDocument Class).
Assuming that there is the single Launch.File element with Name element with value "ULTII":
var document = XDocument.Load(...);
var ultiiElement = document
.Descendants("Launch.File")
.Single(fileElement => fileElement.Element("Name").Value == "ULTII");
ultiiElement.Element("Disabled").Value = "True"; // or true.ToString()
document.Save(...);
This method will do the trick:
public void ChangeNode(string name, string filePath)
{
XDocument xDocument;
using (var streamReader = new StreamReader(filePath))
{
xDocument = XDocument.Parse(streamReader.ReadToEnd());
}
var nodes = xDocument.Descendants("Launch.File");
foreach (var node in nodes)
{
var nameNode = node.Descendants("Name").FirstOrDefault();
if (nameNode != null && nameNode.Value == name)
{
var disabledNode = node.Descendants("Disabled").FirstOrDefault();
if (disabledNode != null)
{
disabledNode.SetValue("True");
}
}
}
using (var streamWriter = new StreamWriter(filePath))
{
xDocument.Save(streamWriter);
}
}
The name you want to pass in is the name of the node that you want to change and the path is the file path to the xml file. So you might call it like:
ChangeNode("ULTII", "C:\\output.xml");
You may need to tidy this up a bit like matching the node name invariant of case or culture but it should get you started.
Hy,
I have for example this xml:
<books>
<book1 name="Cosmic">
<attribute value="good"/>
</book1>
</books>
How can I display it in a listBox control line by line, that the final result it will be a listbox with 5 rows in this case?
In this moment I am prasing the XML using LINQ to XML like this:
foreach (XElement element in document.DescendantNodes())
{
MyListBox.Items.Add(element.ToString());
}
But the final result puts every xml node in one list-box item (including child-nodes).
Does anyone has any idea how can I put the xml line by line in list-box items?
Thanks.
Jeff
A simple solution would use a recursive function like the following:
public void FillListBox(ListBox listBox, XElement xml)
{
listBox.Items.Add("<" + xml.Name + ">");
foreach (XNode node in xml.Nodes())
{
if (node is XElement)
// sub-tag
FillListBox(listBox, (XElement) node);
else
// piece of text
listBox.Items.Add(node.ToString());
}
listBox.Items.Add("</" + xml.Name + ">");
}
Of course, this one will print only the tag names (e.g. <book1> in your example) and not the attributes (name="Cosmic" etc.). I’m sure you can put those in yourself.
If you want to display your raw XML in a list box, use a text stream to read in your data.
using(StreamReader re = File.OpenText("Somefile.XML"))
{
string input = null;
while ((input = re.ReadLine()) != null)
{
MyListBox.Items.Add(input);
}
}
Jeff, maybe it would be much easier to implement (and to read/maintain) with a simple TextReader.ReadLine()?
I don't know what you are trying to achieve, just a suggestion.