1 private void treeView1_MouseUp(object sender, MouseEventArgs e) 2 { 3 4 TreeNode selectnode = this.treeView1.GetNodeAt(e.Location); 5 if (selectnode == null) 6 { 7 this.treeView1.SelectedNode = null; 8 9 } 10 11 } 12 13 private void treeView1_BeforeSelect(object sender, TreeViewCancelEventArgs e) 14 { 15 if (e.Action == TreeViewAction.Unknown) 16 e.Cancel = true; 17 }