Example of tree and Database Association operations in WinForm (C #)

Data | database WinForm tree and Database Association operations are common, and the following code is used in projects to generate trees from a table:

Dataview?dvtree;
???????? Private?void? Inittreebydataset (? Treenodecollection?nds,?string?parentid, huh? Dataset?ds?)
???????? {
???????????? Dvtree?=?new? DataView ();
????????????
???????????? Treenode?tempnode;
????????????
???????????? Dvtree.table?=?ds. Tables[0];

???????????? Determine if the Parentservicetypeid is null and generate different filter conditions
???????????? If? (? parentid?==?) Isnull (Parentservicetypeid, ' Null? Column ')? =? ' Null? Column ' "?)
???????????? {
???????????????? Dvtree.rowfilter?=?parentid?;
????????????}
???????????? Else
???????????? {
???????????????? Dvtree.rowfilter?=? " Parentservicetypeid?= ' "? +?parentid?+" ";
????????????}
????????????
???????????? Foreach? (? Datarowview?drvtree?in?dvtree?)
???????????? {
???????????????? Tempnode?????? =?new? TreeNode ();
???????????????? tempnode.text?=?drvtree["Name"]. ToString ();
???????????????? Tempnode.tag?? =?drvtree["Pkfieldvalue"]. ToString ();
????????????
???????????????? Nds. ADD (Tempnode?);

???????????????? Recursive call
???????????????? Inittreebydataset (Tempnode.nodes,?tempnode.tag.tostring (), DS?);
????????????}
????????
????????}

Two RELATED links: The application of tree-shaped structure in development,
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