custom data binding sample code

[Peter Zaborski]

Hi,

Is there any sample code on how to create a custom data binding object? ie. An object which can be used like:

GridDataBoundGrid.DataSource = myCustomObject;

I can't find any really good samples that describe what I need to do in order to make this possible.

I think the Syncfusion docs say to implement IListSource and/or IList but no samples are available.

My specific situation consists of an outer collection which contains one or more uniformly sized inner collections of floats. I'd like to bind a grid to the outer collection. And have it not only display the data correctly but also update it. And handle row and col headers as well.

Any help greatly appreciated.

-Peter

[Administrator]

Check out the following sample:

\Essential Suite\Grid\Samples\DataBound\Hierarchical\Customers

It binds the grid to an IList.

Let me know if you need more information.

Stefan

[Peter Zaborski]

Thanks for the pointer but I could use a more relevant sample if possible.

My situation is slightly different from the customer sample. I have the following objects (simplified for this example):

Data = Class which implements IList and contains a float[].

Collection = Class containing an ArrayList of Data objects. This class has a public property called DataSource which returns the ArrayList.

I am using

grid.DataSource = Collection.DataSource

for my attempt to bind the grid to the collection.

I would like the grid & collection bound so that each row dipslays the entire float[] from the corresponding Data object. Instead, each row displays each Data object's public properties.

Any samples which do something close to this? I think I have an extra level of nesting in my case which the cutomer sample does not.

[Administrator]

I would have to try and work on such a sample first.

But let me first explain what the grid is looking for:

When you set the .DataSource for the grid it will check if the data source is IList derived and then it will check if the IList has a strongly typed indexer. If that is the case then the returned type of the strongly typed indexer is checked. So make sure the DataSource you assign to the grid has a indexer like

MyData this[int index] { get; set; }

The next thing is MyData should have a public default constructor that does not need any arguments.

This is because the grid will try to instantiate a sample object of MyData.

Once the grid has access to a instance of MyData it will then query the object for its fields.

I am right now not sure if it will detect float[]. I need to take a closer look. If it does not work we will have to add support for that in the grid source code then.

A workaround would be then to implement ITypedList in the collection that you assign to .DataSource

Stefan

[Peter Zaborski]

That helps a lot, thanks. Any sample you can provide would be great but this gives me a great place to start.

-Peter

[Faulhaber]

Hello Stefan,

it's an old thread, but it's the only matching topic i found

>So make sure the DataSource you assign to the grid has a indexer like
>
>MyData this[int index] { get; set; }
>
>The next thing is MyData should have a public default constructor that does not need any arguments.
>
>This is because the grid will try to instantiate a sample object of MyData.


I have an object like described above, but the "MyData" object contains a list of objects that represents the columns.
But the problem is that i can't initialize a sample object in the parameterless constructor because of the dynamic columns.

In the DataTable-object a new row is created by the table.NewRow() method with the defined schema of the table. The DataTable doesn't have an idexer, what does the grid there and what have i to do to implement this?

I hope you can give me a hint.

Regards
Christian

[haneefm]

Hi Christian,

Thank you for your update.

I have tested the attached sample to reproduce this issue, but could not get this. Maybe I am not following the steps that you are doing. Is it possible for you to upload us a minimal sample to reproduce the issue here? This will help us to analyse the issue further.

Sample : AddColumnCollection.zip

Best regards,
Haneef

[Faulhaber]

Hello Haneef,

i got my problem solved. I had to implement the "ITypedList"-interface that the grid creates the columns.


Thank you for your efforts.

Regards
Christian