TreeDataGrid column types

TreeDataGrid currently supports three different column types:

• TextColumn

• HierarchicalExpanderColumn

• TemplateColumn

TextColumn

TextColumn is useful when you want all cells in the column to have only text values. Usually, everything you need to instantiate TextColumn class is

new TextColumn<Person, string>("First Name", x => x.FirstName)

The first generic parameter here is your model type basically, the place where you want to grab data from. Person in this case. The second generic parameter here is the type of the property where you want to grab data from. In this case, it is a string, it will be used to know exactly which type your property has.

This is the signature of the TextColumn constructor. There are two most important parameters. The first one will be used to define the column header, usually, it would be a string. In the sample above it is "First Name". The second parameter is an expression to get the value of the property. In the sample above it is x => x.FirstName.

Note: The sample above is taken from this article. If you feel like you need more examples feel free to check it, there is a sample that shows how to use TextColumns and how to run a whole TreeDataGrid using them.

HierarchicalExpanderColumn

HierarchicalExpanderColumn can be used only with HierarchicalTreeDataGrid (a.k.a TreeView) that's what Hierarchical stands for in its name, also it can be used only with HierarchicalTreeDataGridSource. This type of columns can be useful when you want cells to show an expander to reveal nested data.

That's how you instantiate HierarchicalExpanderColumn class:

new HierarchicalExpanderColumn<Person>(new TextColumn<Person, string>("First Name", x => x.FirstName), x => x.Children)

HierarchicalExpanderColumn has only one generic parameter, it is your model type, same as in TextColumn, Person in this case.

Let's take a look at the HierarchicalExpanderColumn constructor.

The first parameter in the constructor is a nested column, you would usually want to display something besides the expander and that's why you need this parameter. In the sample above, we want to display text and we use TextColumn for that. The second parameter is a selector of the child elements, stuff that will be displayed when Expander is in the expanded state below the parent element.

Note: The sample above is taken from this article. If you feel like you need more examples feel free to check it, there is a sample that shows how to use HierarchicalExpanderColumn and how to run a whole TreeDataGrid using it.

TemplateColumn

TemplateColumn is the most customizable option to create a column. You can put basically everything that you can put into IDataTemplate into this column cells.

That's how you instantiate TemplateColumn class:

new TemplateColumn<Person>(
                        "Selected",
                        new FuncDataTemplate<FileTreeNodeModel>((a,e) => new CheckBox()))

TemplateColumn has only one generic parameter, it is your model type, same as in TextColumn, Person in this case. Code above will create a column with header "Selected" and CheckBox in each cell.

TemplateColumn has only two required parameters. The first one is the column header as everywhere. The second is IDataTemplate basically, a template that contains stuff that you want to be displayed in the cells of this column.