Vb. Implementation of hierarchical data binding TreeView in Net

Summary: In VB6, the TreeView is often used to represent hierarchical data, but the related code that interacts with the database requires a lot of manual coding; In vb.net, because of the enhancement of the data binding function and the enhancement of language features, it is easy to bind the TreeView to the hierarchical data, this article will first establish a dbtreeview that inherits from the TreeView and then use a unit (department) 's hierarchical data is bound to Dbtreeview and provides code to interact with the database.

1, from the level of data to express the way to start

In this example, the Department table (Department) has five fields, such as the following table:

Field name	Field	Type description
Id	Automatic numbering	Key
Code	String	Coding
Name	String	Name
Pid	Int	ID of parent Node
CPtr	Boolean	Do you have any child nodes?

　　

2, inherit from the TreeNode Mytreenode

In Mytreenode, three new properties are added, such as the following table:

Property name	Type	Description
Value	Object	Key
Pid	Object	ID of parent Node
CPtr	Boolean	Do you have any child nodes?

　　

In the Init event, set the three properties and the Text property, based on the four parameters passed in.

3, bind the Dbtreeview to the data source

Property name	Type	Description
Datasource	DataView	Dbtreeview data sources use DataView instead of object
Value	Member	String value member (column name of data source [DataView])
Display	Member	string display (in text) member
Pid	Member	String Parent ID Member
CPtr	Member	Whether string has child nodes