LINQ to SQL and Gridview

[Donta]

Anyone have any good examples of successfully binding a LINQ result with a parent child relationship to a gridview?

Thanks, Donta

[gerbrand]

Hi Donta,

I don't know if you can link a linq result to the radgridview.DataSource, never try it. But if you have your linq object you can easily readout the linq object and add your rows to the gridview.

If I have some time today I'm going to try to bind a linq object directly to the gridview.

Will let you know if it worked.

[Donta Dalpoas]

I can bind the linq result to the grid and the parent level of rows is rendered. How do you set the datasource of the childtemplate to a property of the linq result is the more targeted question.

Thanks for the reply...Donta

[gerbrand]

Hi Donta,

Maybe this can help you?

	radGridView1.DataSource = nwindDataSet.Suppliers; //your linq result master/parent
	GridViewTemplate template = new GridViewTemplate();
	template.DataSource = nwindDataSet.Products; //your linq result childs
	radGridView1.MasterGridViewTemplate.ChildGridViewTemplates.Add(template);
	GridViewRelation relation = new GridViewRelation(radGridView1.MasterGridViewTemplate);
	relation.ChildTemplate = template;
	relation.RelationName = "SuppliersProducts";
	relation.ParentColumnNames.Add("SupplierID");
	relation.ChildColumnNames.Add("SupplierID");
	radGridView1.Relations.Add(relation);

This is an example from the help files of the radgridview. Can be found under topic: Hierarchical Grid -> Binding to Hierarchical Data Programmatically.

[Donta Dalpoas]

Yes...I've read this. This seems to be designed to handle the situation in which you have two separate "tables" or List<> of objects to use as the datasources. In my case I have an object structured like the following:

objLINQResult
Parent
   Child
   Child
   Child
Parent
   Child
   Child
Parent
   Child

I'm binding the objLINQResult to the datasource of the grid but since the children are all members of each parent I have no datasource in the LINQ object to bind to the childtemplate. The hierarchy is already built-in basically.

Make sense?

Thanks, Donta

[gerbrand]

Okay, I had the same situation.

Try this sample code:

	foreach (var item in sortedByLft)
	{
	if (item.ParentId == 0) //we've got a parent
	{
	gridview.MasterGridViewTemplate.Rows.Add(new object[] { item.Id, item.Name });
	template = rgvNetwork.MasterGridViewTemplate.ChildGridViewTemplates[0];
	}
	else // we've got or child
	{
	if (template == null) continue;
	template.Rows.Add(new object[] { item.ParentId, item.Id, item.Name});
	}
	}

the sortedByLft is my linq result
where I sorted parents and childs

make sure you made a relationship like this:

	gridview.MasterGridViewTemplate.Columns.Add(new GridViewDataColumn { FieldName = "Id", HeaderText = "Id", HeaderTextAlignment = ContentAlignment.MiddleCenter });
	gridview.MasterGridViewTemplate.Columns.Add(new GridViewDataColumn { FieldName = "Name", HeaderText = "Name", HeaderTextAlignment = ContentAlignment.MiddleCenter });
	var template = new GridViewTemplate { AllowAddNewRow = false, AutoSizeColumnsMode = GridViewAutoSizeColumnsMode.Fill };
	template.Columns.Add(new GridViewTextBoxColumn { FieldName = "Id", IsVisible = false });
	template.Columns.Add(new GridViewTextBoxColumn { FieldName = "childid", HeaderText = "Child id", HeaderTextAlignment = ContentAlignment.MiddleCenter});
	template.Columns.Add(new GridViewTextBoxColumn { FieldName = "Childname", HeaderText = "Child name", HeaderTextAlignment = ContentAlignment.MiddleCenter});
	var relation = new GridViewRelation(gridview.MasterGridViewTemplate)
	{
	ChildTemplate = template,
	RelationName = "relationshipID"
	};
	relation.ParentColumnNames.Add("Id");
	relation.ChildColumnNames.Add("Id");
	gridview.Relations.Add(relation);

also before every bind of the object clear your rows

	gridview.MasterGridViewTemplate.Rows.Clear();
	gridview.MasterGridViewTemplate.ChildGridViewTemplates.Clear();

I think that should solved it.

[Donta Dalpoas]

I'll give it a shot later today...thanks for all the help.

Donta