Data Binding in Windows Forms TreeView

TreeViewAdv binds to any table, collection of tables, custom objects, etc. by using the TreeViewAdv.DataSource property.

The following are the ways to bind various data sources to TreeViewAdv.

  1. Binding to Self-Referencing Data
  2. Binding to Data Relations
  3. Binding to Object-Relational Data

Binding to Self-Referencing Data

In this type, TreeViewAdv binds to self-referencing data where the TreeViewAdv is bound to single table instead of multiple related tables.

Parent-Child relationship for all the records is defined by setting the ParentMember and ChildMember properties to the respective fields in the data source. If the Parent ID of one record has the respective value in the Child ID of any other records from the table, then that record is considered to have parent. If not, then the record is considered to have no parents and, in such case, it won’t be visible in the TreeViewAdv.

If the value in ParentMember field of some records matches with the TreeViewAdv.SelfRelationRootValue, then those records are considered as root nodes of TreeViewAdv.

Property Description
DataSource Gets or sets the data source object in TreeViewAdv.
DisplayMember Gets or sets the field that populates the Text property of the TreeNodeAdv in TreeViewAdv.
ValueMember Gets or sets the field that populates the Value property of TreeNodeAdv in TreeViewAdv.
ParentMember Gets or sets a value indicating the parent data field which behaves as a parent node in TreeViewAdv.
ChildMember Gets or sets a value indicating the child data field which behaves as a child node in TreeViewAdv.
DataMember Gets or sets the table name that should be bound to the TreeViewAdv.
CheckedMember Gets or sets a value indicating the field to populate the state of checkbox of TreeNodeAdv in TreeViewAdv.
SelfRelationRootValue Gets or sets the value that defines the root object in a self-relational mode when data source is used to define the underlying tree data.

SelfReferencingData
In the above table, North America is declared as root node by setting appropriate (or matching) SelfRelationRootValue. Here the value is set to empty and so North America is added as root node.

United States is declared as child of North America by setting appropriate ContinentID. Here the value is set to 1 and it matches the CountryID of North America. As a result, United States is added as child node of North America.

treeViewAdv1.SelfRelationRootValue = "";
treeViewAdv1.DisplayMember = "Name";
treeViewAdv1.ParentMember = "ContinentID";
treeViewAdv1.ChildMember = "CountryID";
treeViewAdv1.ValueMember = "Capital";
treeViewAdv1.CheckedMember = "IsActive";
treeViewAdv1.DataSource = Table_1;
treeViewAdv1.SelfRelationRootValue = ""
treeViewAdv1.DisplayMember = "Name"
treeViewAdv1.ParentMember = "ContinentID"
treeViewAdv1.ChildMember = "CountryID"
treeViewAdv1.ValueMember = "Capital"
treeViewAdv1.CheckedMember = "IsActive"
treeViewAdv1.DataSource = Table_1

NOTE

1) Root nodes are parent less (for example, see “North America” node in the image above). All root nodes must have their parent member values (TreeViewAdv.ParentMember) set to TreeViewAdv.SelfRelationRootValueproperty. If the property is not specified then, you may notice empty TreeViewAdv. So, to avoid this, we suggest that you always set parent member values with TreeViewAdv.SelfRelationRootValue for root nodes.
2) You must specify TreeViewAdv.DisplayMember, TreeViewAdv.ParentMember, TreeViewAdv.ChildMember properties mandatorily to populate the appropriate TreeViewAdv.

Binding to Data Relations

In this type, TreeViewAdv are bound to database where levels are created using DataRelation class. Each DataRelation class object describes the parent data being bound to, the child data being bound to and the data columns used to populate Text and selected Value properties of the nodes.

S.No Property Name Description
1 DataRelations Contains the collection of DataRelation in TreeViewAdv.
S.No Class Name Description
1 DataRelation Represents a parent/child relationship between two DataTable objects.

DataRelations

Syncfusion.Windows.Forms.Tools.DataRelation childRelation1;
Syncfusion.Windows.Forms.Tools.DataRelation childRelation2;
Syncfusion.Windows.Forms.Tools.DataRelation childRelation3;

childRelation1 = new Syncfusion.Windows.Forms.Tools.DataRelation(Table_2, "Table_2", "SubFolderName1", "ChildFolder", "SubFolderChild1", "SubFolderName1", "Checked");

childRelation2 = new Syncfusion.Windows.Forms.Tools.DataRelation(Table_3, "SubFolderName2", "SubFolderChild1", "SubFolderChild2");

childRelation3 = new Syncfusion.Windows.Forms.Tools.DataRelation(Table_4, "Table_4", "SubFolderName3", "SubFolderChild2", "SubFolderChild3", "SubFolderName3", "Checked");

treeViewAdv1.DataRelations.Clear();

treeViewAdv1.DisplayMember = "FolderName";
treeViewAdv1.ParentMember = "ParentFolder";
treeViewAdv1.ChildMember = "ChildFolder";

treeViewAdv1.DataRelations.Add(childRelation1);
treeViewAdv1.DataRelations.Add(childRelation2);
treeViewAdv1.DataRelations.Add(childRelation3);

treeViewAdv1.DataSource = Table_1;
Dim childRelation1 As Syncfusion.Windows.Forms.Tools.DataRelation
Dim childRelation2 As Syncfusion.Windows.Forms.Tools.DataRelation
Dim childRelation3 As Syncfusion.Windows.Forms.Tools.DataRelation

childRelation1 = New Syncfusion.Windows.Forms.Tools.DataRelation(Table_2, "SubFolder1", "SubFolderName1", "FolderChild", "SubFolderChild1", "SubFolderName1", "Checked")    

childRelation2 = New Syncfusion.Windows.Forms.Tools.DataRelation(Table_3, "SubFolderName2", "SubFolderChild1", "SubFolderChild2")

childRelation3 = New Syncfusion.Windows.Forms.Tools.DataRelation(Table_4, "SubFolder3", "SubFolderName3", "SubFolderChild2", "SubFolderChild3", "SubFolderName3", "Checked")

treeViewAdv1.DataRelations.Clear()

treeViewAdv1.DisplayMember = "FolderName"
treeViewAdv1.ParentMember = "ParentFolder"
treeViewAdv1.ChildMember = "ChildFolder"

treeViewAdv1.DataRelations.Add(childRelation1)
treeViewAdv1.DataRelations.Add(childRelation2)
treeViewAdv1.DataRelations.Add(childRelation3)

treeViewAdv1.DataSource = Table_1

DataRelations

NOTE

1) In this type, you must specify DisplayMember, ParentMember, ChildMember properties mandatorily to populate appropriate TreeViewAdv.
2) Here levels are created using DataRelation, so if you want to dynamically add new level then you need to create new instance of DataRelation and add it to TreeViewAdv.DataRelations property with proper relation first.

Binding to Object-Relational Data

In this type, TreeViewAdv binds to class objects which have collections associated with other dependent class objects establishing proper relation.

Object-RelationalData

In this illustration, there are three classes named Continent, Country and State. In this case the Continent class has a property named ContinentName, ContinentID and Country_List which is a collection of Country objects. This is the first relation. The second relation is the State_List property in the Country class, it offers a reference to a collection of State.

You must specify the DisplayMember, ChildMember property and here you need not define ParentMember property. TreeViewAdv must display it in hierarchical view.

S.No Properties Description
1 DisplayMember Defines which property of the class needs to be in node's text. Example: Continent -> ContinentName, Country -> CountryName, State -> StateName.
2 ChildMember Defines the class order. Example: Continent -> First level, Country -> Second level, State -> Third level.
treeViewAdv1.DisplayMember = "ContinentName\\CountryName\\StateName"; 
treeViewAdv1.ChildMember = "Continent\\Country\\State";
treeViewAdv1.DisplayMember = "ContinentName\\CountryName\\StateName"
treeViewAdv1.ChildMember = "Continent\\Country\\State"

Object-RelationalData

See Also

How to get value specified by ValueMember path for CheckedNodes?