dotnet windows forms databinding: Hi,

[quoted text, click to view]

But there isn't a *property* (fields won't work) named "Service" on your
nested class...

HTH,
Greetings



[quoted text, click to view]

I have a problem databind a ListBox to an array of objects defined as a
nested class. The problem is that instead of displaying the text of the
field, it displays the string "<namespace>.NestedTestClass+ProductItem",
which as far as I can tell is the default value returned by ToString() of the
ProductItem class itself.

Thus the problem seems to be that databinding fails to properly resolve the
DisplayMember setting because the type is nested.

I really need this to work, since the production version of this code uses
generics to create numerous concrete subclasses.

Is there some special syntax for the DisplayMember field to make this work?

Below is a test class that shows the problem.

public class NestedTestClass
{
internal List<ProductItem> m_ProductItems = new List<ProductItem>(10);

public class ProductItem
{
public int Product;
public string Code;
public string Description;

public ProductItem(int product, string code, string description)
{
Product = product;
Code = code;
Description = description;
}
}

public NestedTestClass()
{
m_ProductItems.Add(new ProductItem(0, "0", "Product 0"));
m_ProductItems.Add(new ProductItem(1, "1", "Product 0"));
m_ProductItems.Add(new ProductItem(2, "2", "Product 0"));
m_ProductItems.Add(new ProductItem(3, "3", "Product 0"));
}

public ProductItem[] ProductsArray
{
get { return m_ProductItems.ToArray(); }
}

public List<ProductItem> ProductsList
{
get { return m_ProductItems; }
}
}

The databinding code:

NestedTestClass test = new NestedTestClass();
NestedTestClass.ProductItem[] list = test.ProductsArray;
listBox1.DisplayMember = "Service";
listBox1.DataSource = list;

Please advice!

Regards;
/jb

------------------------
Jonny Bergdahl

Hi Jonny,

Firstly, the class ProductItem doesn't have a property. Only property can
be bound to a control.

Secondly, do you type the 'Service' in the line of code
'listBox1.DisplayMember = "Service";' by mistake? There isn't any field or
property called 'Service' in the class ProductItem.

In short, you should add a public property for each field in the class
ProductItem and then bound one of the property to the listbox.

Below is a sample.

public class ProductItem
{
private int _Product;
private string _Code;
private string _Description;

public string Description
{
get { return _Description; }
set { this._Description = value; }
}
public int Product
{
get { return _Product; }
set { _Product = value; }
}
public string Code
{
get { return _Code; }
set { _Code = value; }
}

public ProductItem(int product, string code, string description)
{
_Product = product;
_Code = code;
_Description = description;
}
}

Hope this helps.
If you have anything unclear, please feel free to let me know.


Sincerely,
Linda Liu
Microsoft Online Community Support

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Hi Jonny,

How about the problem now?

If the problem is not solved or you have anything unclear, please feel free
to let me know.

Thank you for using our MSDN Managed Newsgroup Support Service!

Sincerely,
Linda Liu
Microsoft Online Community Support

Yes, that solved my problem.

regards;