Re: finding a specific node in XML with given string - C# Discussion Boards

Re: How Autocomplete works in Windows application

NarVish21-Apr-09 20:10

NarVish

21-Apr-09 20:10

Thanks alot Eddy Vluggen!!
Its working..

finding a specific node in XML with given string

Emmet_Brown21-Apr-09 3:25

Emmet_Brown

21-Apr-09 3:25

Hi
I want to find a node from its text in an XML file with given string.

I'm taking this text from a textbox in my application and I want to find this node from XML file and
do some changes on it like changing childrens' texts or deleting the node and it's children from file.

any help :/ ?

Re: finding a specific node in XML with given string

Jimmanuel21-Apr-09 3:39

Jimmanuel

21-Apr-09 3:39

Manipulate XML data with XPath and XmlDocument[^]

Badger | [badger,badger,badger,badger...]

Re: finding a specific node in XML with given string

Rob Philpott21-Apr-09 3:47

Rob Philpott

21-Apr-09 3:47

There's usually two approaches to XML things like this, a streaming one which has a small memory footprint or the document approach where you load the whole xml into memory. The latter is easier if your xml is not too big.

(There's also a swanky new way using Linq2Xml which I know nothing about).

Something *like* :

XmlDocument doc = new XmlDocument();
doc.Load(<the file="">);

XmlNodeCollection nodes = doc.SelectNodes("//<element name="">");</element></the>

That will return you all the child elements with the name your looking for. You can iterate over them etc.

You'll need to brush up a bit on XPath to do it, but its easy enough once you've got your head around that.

Regards,
Rob Philpott.

Re: finding a specific node in XML with given string

Emmet_Brown21-Apr-09 4:19

Emmet_Brown

21-Apr-09 4:19

thanks for replies

I've changed my app a bit.
to be more precisive, the XML document is like:

<app>
<appname>application1</appname>
<action><arg>argument1</arg><ges>gesture1</ges></action>
</app>
<app>
<appname>application2</appname>
<action><arg>argument2</arg><ges>gesture2</ges></action>
</app>
..etc

I'm choosing a node from my treeview first, and the node in the treeview has the name with "title" node's inner text, (so arg and ges nodes are siblings for the title)

what I'm doing right now is;

XmlDocument doc = new XmlDocument();
doc.Load();


XmlNode editing = doc.SelectSingleNode(treeView1.SelectedNode.Text); //here I'm trying to find a node with selected single node's text

editing.NextSibling.InnerText = "changedText"; //and here I'm trying to change the inner text of the arg or ges nodes' innertext

in fact, application gives "Object reference not set to an instance of an object." message pointing the "XmlNode editing = doc.blahblah" line

any further help?

edit: there's also a <title>NodeTitle1/2</> tag among arg and ges nodes which I forgot to add to xml example

Re: finding a specific node in XML with given string

Rob Philpott21-Apr-09 4:26

Rob Philpott

21-Apr-09 4:26

The problem lies on you SelectSingleNode line.

You have to treat XPath statements a bit like directory structures. Unless there's a top level node of that name you won't find it.

You can use \\ to denote any (this node and all below). Try the below:

XmlNode editing = doc.SelectSingleNode(@"\\" +treeView1.SelectedNode.Text);

Regards,
Rob Philpott.

Re: finding a specific node in XML with given string

Emmet_Brown21-Apr-09 4:39

Emmet_Brown

21-Apr-09 4:39

yeah this seems like the answer, but I couldn't understand the string structure

I've pasted your line in my code and it still gives an error:

XPathException was unhandled:
'\\Applications' has an invalid token.

:/

Re: finding a specific node in XML with given string

Rob Philpott21-Apr-09 4:41

Rob Philpott

21-Apr-09 4:41

um, try forward slashes rather than backslashes - my memory may be letting me down....

Regards,
Rob Philpott.

Re: finding a specific node in XML with given string

Emmet_Brown21-Apr-09 4:45

Emmet_Brown

21-Apr-09 4:45

Thanks Rob you've been very helpful

but now another error occured in the next line,

XmlNode editing = dom.SelectSingleNode(@"//" + treeView1.SelectedNode.Text);  //this is not a problem any more
editing.NextSibling.InnerText = "changedText"; //this line says : "NullReferenceException was unhandled....  Object reference not set to an instance of an object.

I promise, no more questions =))

Re: finding a specific node in XML with given string

fly90421-Apr-09 4:09

fly904

21-Apr-09 4:09

Have a look at this Linq example.[^]

hmmm pie

Image on Clipboard

Anubhava Dimri21-Apr-09 2:43

Anubhava Dimri

21-Apr-09 2:43

Hi All,
I have generating a problem when i am tring to Copy Image in Clipboard.

Bitmap bmp1 = new Bitmap(panel3.ClientRectangle.Width, panel3.ClientRectangle.Height);
panel3.DrawToBitmap(bmp1, panel3.ClientRectangle);
Clipboard.SetImage(bmp1);

When i paste it on Paint and Print it then Image not Showing properly. Image is streatcing.

Thanks

If you can think then I Can.

get a graphica in picturebox from one form to another [modified]

R.Krishnakumar21-Apr-09 2:12

R.Krishnakumar

21-Apr-09 2:12

In one form i added graphics using paint in the picture box, how can i get the same graphics in another form's picture box,at the same time graphics should run in both the forms using c#

modified on Tuesday, April 21, 2009 8:26 AM

Re: get a graphica in picturebox from one form to another

Rob Philpott21-Apr-09 3:23

Rob Philpott

21-Apr-09 3:23

Derive a class from Picture box and override the OnPaint handler. You can then just treat your new class as a control and drop it on whatever forms you want.

Regards,
Rob Philpott.

Insert a class instance into a row in data table

Hari.net21-Apr-09 1:01

Hari.net

21-Apr-09 1:01

Hi,

I need to insert an instance of user defined class into a datarow in datatable.
I tried casting to the class name,object everything, but its always showing as string object. Anybody having any idea about this... A sample code is given below....

dataRow[dataColumn] = (MyClass)value;

Here value is an object of type MyClass...bt after execution, the result in dataRow[dataColumn] is of type string object..

Please help...its urgent...

Re: Insert a class instance into a row in data table

Le centriste21-Apr-09 1:14

Le centriste

21-Apr-09 1:14

How do you want your object to be inserted in the row?

Re: Insert a class instance into a row in data table

Hari.net21-Apr-09 1:26

Hari.net

21-Apr-09 1:26

Just want to insert it as class object...

foreach(MyClass obj in MyClassCollection)
     {
         dataRow[dataColumn] = obj;
     }

Just this, nothing more... bt dis is showing as "MyClass" of type object{string}

Re: Insert a class instance into a row in data table

Le centriste21-Apr-09 2:01

Le centriste

21-Apr-09 2:01

what is the type of dataColumn?

Re: Insert a class instance into a row in data table

Henry Minute21-Apr-09 1:16

Henry Minute

21-Apr-09 1:16

I am not sure, but I think that it is using the ToString() method. As it is managing to store the class, I can only assume that the datacolumn type is one of the text variants (varchar, nvarchar etc.).

I think that you are going to have to use blob storage techniques, together with (possibly binary) serialization, to do this.

Maybe you will get lucky and someone who has done something like this will help.

Henry Minute

Do not read medical books! You could die of a misprint. - Mark Twain
Girl: (staring) "Why do you need an icy cucumber?"
“I want to report a fraud. The government is lying to us all.”

Re: Insert a class instance into a row in data table

musefan21-Apr-09 1:16

musefan

21-Apr-09 1:16

well i cant image you are wanting to display the class in any way in a cell so why dont you try using the Tag property of the DataRow? I am assuming you just need to get information from the class why you have a row selected.

dataRow.Tag = myClass;

then when you need it you can just do...

MyClass myClass = (MyClass)dataRow.Tag;

Life goes very fast. Tomorrow, today is already yesterday.

Re: Insert a class instance into a row in data table

S. Senthil Kumar21-Apr-09 1:59

S. Senthil Kumar

21-Apr-09 1:59

1. How do you know the value is a string?
2. The property indexer of DataRow is typed to return object, but you can cast it back to the original type.

Regards
Senthil [MVP - Visual C#]
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Crop a circle image from a square picture

Babita Shivade21-Apr-09 0:43

Babita Shivade

21-Apr-09 0:43

hi,
I making a windows application in C# and my problem is that,
I have a square picture. I need to draw a circle on it, and everything
outside that circle to be set to a certain color, so the image looks framed

On other words, I want to crop a circle form a rectangular picture

Any hints/any help ..........

thanks in advance

Re: Crop a circle image from a square picture

Luc Pattyn21-Apr-09 1:31

Luc Pattyn

21-Apr-09 1:31

Hi,

the Graphics class holds all you need: methods FromImage() and DrawEllipse() should do it.
You may use several DrawEllipse() with increasing radius to remove the four corners, or just one
with appropriate radius and Pen width.

Smile | :)

Luc Pattyn [Forum Guidelines] [My Articles]

Avoiding unwanted divs (as in "articles needing approval") with the help of this FireFox add-in

Re: Crop a circle image from a square picture

Babita Shivade21-Apr-09 2:06

Babita Shivade

21-Apr-09 2:06

thanks for give me such idea....
can you tell me how to fill color on the remaining portion of the image when we make a circle on it.

thanks.........

Re: Crop a circle image from a square picture

Skymir21-Apr-09 2:49

Skymir

21-Apr-09 2:49

Make the Ellipse bigger than the picture and use a huge pen width.

The true man wants two things: danger and play. For that reason he wants woman, as the most dangerous plaything.

C# -Savefile Dialog to save an image file

vijaywithu21-Apr-09 0:30

vijaywithu

21-Apr-09 0:30

hi friends I am new to .NET,
I have the following code to save an image file in specific location.
It does compile and it is showing that null reference eexception is unhandled
it is asking to create an object instance in this line (System.Drawing.Imaging.ImageFormat)
how can it be done any help please

SaveFileDialog save = new SaveFileDialog();
save.Filter = "JPeg Image|*.jpg|Bitmap Image|*.bmp|Gif Image|*.gif";
save.Title = "Save the File";
save.ShowDialog();
string fName = save.FileName;

if (save.FileName != "")
{
System.IO.Stream fileStream = (System.IO.FileStream)save.OpenFile();

switch (save.FilterIndex)
{
case 1:
this.button7.Image.Save(fileStream, System.Drawing.Imaging.ImageFormat.Jpeg);
break;
case 2:
this.button7.Image.Save(fileStream, System.Drawing.Imaging.ImageFormat.Gif);

break;
case 3:
this.button7.Image.Save(fileStream, System.Drawing.Imaging.ImageFormat.Bmp);
break;
}
fileStream.Close();
}
}

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