C# TreeView control usage code

Current selected item:
Add top-level nodes: ("Key", "Text")
Add nodes of the same level: ("Key", "Text")
Add child nodes: ("Key", "Text")
Expand all: ()
Collapse all: ()
Reset TreeView
The database table structure is: ID Type Name Parent ID

Copy the codeThe code is as follows:

 
private void loadTreeView() 
{ 
this.Product Category (superCargoDataSet1.Product Category);
DataTable table = superCargoDataSet1. Product category;
DataRow[] row = ("Parent ID=0");
foreach (DataRow r in row) 
{ 
TreeNode node = Product category (r["ID"].ToString(), r["type name"].ToString());
recursionShow(node, r["ID"].ToString()); 
} 
} 
private void recursionShow(TreeNode nodes, string id) 
{ 
DataTable table = superCargoDataSet1. Product category;
DataRow[] row = ("parent ID=" + id);
if (row != null) 
{ 
foreach (DataRow r in row) 
{ 
TreeNode node = (r["ID"].ToString(), r["type name"].ToString());
recursionShow(node, r["ID"].ToString()); 
} 
} 
} 

Delete selected nodes and their children nodes, and delete corresponding records in the database at the same time
The database table structure is: ID Type Name Parent ID

Copy the codeThe code is as follows:

 
private void delete ToolStripButton_Click(object sender, EventArgs e)
{ 
if (Product Category != null)
{ 
DataRow[] rowChildren = superCargoDataSet1.Product Category.Select("ID=" +Product Category());
if (rowChildren != null) 
{ 
foreach (DataRow row in rowChildren) 
{ 
delete node(row["ID"].ToString());
(); 
} 
} 
Product category ();
} 
} 
private void delete node(string id)
{ 
DataRow[] rowChildren = superCargoDataSet1.Product Category.Select("parent ID=" + id);
if (rowChildren != null) 
{ 
foreach (DataRow row in rowChildren) 
{ 
delete node(row["ID"].ToString());
(); 
} 
} 
} 

Right-click TreeView to select

Copy the codeThe code is as follows:

 
Private void treeView left_MouseDown( object sender, MouseEventArgs e)
{ 
if(  ==  ) 
{ 
TreeNode node = treeView left.GetNodeAt ( , );
if( node != null )//Right-click the node not selected, and the currently selected node does not change.  VS2005 is the case.
{ 
left.SelectedNode = node;
} 
} 
} 