XML Problem as XMLDatasource from windowsapp to asp.net


M

Miro

Sorry for the crosspost, but I really am stumped here. (vs2008pro)
The problem is using an XML file as a Datasource in asp.net that was created
in a vb.net winforms app.

Any explination would be much appreciated.

I will try to explain the best way I can with the following example:

Step1...
Create a vb.net windowsform application and manually add a dataset.
Create 1 table in the dataset (this dataset and table are not connected to a
physical file).
I created a table called Colors and added the following columns.

ID-key
Color-String
ImageUrl-String

Put a datagridview on the windows form and a button.
Bind the datagridview to dataset1 and the bindingsource to the colors table.

Put a commandbutton on the form,
Add this code
DataSet1.AcceptChanges()
DataSet1.WriteXml("C:\Temp\myxmlfile.xml")
DataSet1.WriteXmlSchema("C:\Temp\myxmlfile.xsd")

Now, run the app and add data to the datagrid, and push the command button.
Now you have an xml file created directly from the dataset with some data.

I went and took the xml file and changed it around a bit and saved it with a
different name: myxmlfile_canBind.xml
===here is the xmlfile changed.
<?xml version="1.0" encoding="utf-8" ?>
<DataSet1>
<Colors>
<AColor Id="1" Color="Black" ImageUrl="somewhere" />
<AColor Id="2" Color="Red" ImageUrl="somewhereelse" />
</Colors>
</DataSet1>
====
Here is a snippet of the original
<?xml version="1.0" standalone="yes"?>
<DataSet1 xmlns="http://tempuri.org/DataSet1.xsd">
<Colors>
<ID>1</ID>
<Color>Black</Color>
<ImageUrl>somewhere</ImageUrl>
</Colors>
<Colors>
<ID>2</ID>
<Color>Red</Color>
<ImageUrl>SomewhereElse</ImageUrl>
</Colors>
</DataSet1>
===
***Take note how the two xmls look different. (the one created by vb.net
writexml and the one created manually)

Step2:
Now create a brand new asp.net project,
Copy all the xml files created in to the App_Data folder.
Add a dropdown on the aspx page, and an xmldatasource.
The XMLDatasource1 has the properties set as follows:
DataFile: ~/App_Data/myxmlfile_canBind.xml
XPath: DataSet1/Colors/AColor

Bind the dropdown to the xmlDatasource1 - notice how you can pick an ID for
the value and the color for the display.
-It works...

Now try and bind to the second xml file ( that was actually created through
vb ) by writing an xml with the same step2.
Dont forget to pick a different Xpath. I cannot tell you what it is cause I
cannot get this part working.
-You cannot...

Funny how you cannot bind to a valid xmldatasource that was actually created
with the writeXML

Cheers'

Miro
 
Ad

Advertisements

M

Martin Honnen

Miro said:
Now try and bind to the second xml file ( that was actually created
through vb ) by writing an xml with the same step2.
Dont forget to pick a different Xpath. I cannot tell you what it is
cause I cannot get this part working.

The XmlDataSource exposes XML attributes of XML elements as properties
you can bind to. So you either need to ensure that your data table
columns are output as attributes or you need to apply an XSLT stylesheet
to transform elements you want to bind to to attributes.
If you want to ensure that columns are output as attributes then set e.g.

foreach (DataColumn col in yourDataTable.Columns)
{
col.ColumnMapping = MappingType.Attribute;
}
 
Ad

Advertisements

M

Miro

Thank you martin for that explination.

I couldn't understand why my version of the xml file would not work.

Cheers'

Miro
 

Ask a Question

Want to reply to this thread or ask your own question?

You'll need to choose a username for the site, which only take a couple of moments. After that, you can post your question and our members will help you out.

Ask a Question

Top