C# 从数据库填充TreeView
我有一个名为Topics的数据库表,其中包括以下字段: 托皮西德 名称 父ID 通过使用它们,我想在c中填充一个树视图。我该怎么做C# 从数据库填充TreeView,c#,asp.net,database,webforms,treeview,C#,Asp.net,Database,Webforms,Treeview,我有一个名为Topics的数据库表,其中包括以下字段: 托皮西德 名称 父ID 通过使用它们,我想在c中填充一个树视图。我该怎么做 提前谢谢…可能是这样的。如果您需要更多,请详细说明您到底想做什么 //In Page load foreach (DataRow row in topics.Rows) { TreeNode node = new TreeNode(dr["name"], dr["topicId"]) node.PopulateOnDemand = true;
提前谢谢…可能是这样的。如果您需要更多,请详细说明您到底想做什么
//In Page load
foreach (DataRow row in topics.Rows)
{
TreeNode node = new TreeNode(dr["name"], dr["topicId"])
node.PopulateOnDemand = true;
TreeView1.Nodes.Add(node);
}
///
protected void PopulateNode(Object sender, TreeNodeEventArgs e)
{
string topicId = e.Node.Value;
//select from topic where parentId = topicId.
foreach (DataRow row in topics.Rows)
{
TreeNode node = new TreeNode(dr["name"], dr["topicId"])
node.PopulateOnDemand = true;
e.Node.ChildNodes.Add(node);
}
}
不完全是
处理树的最佳方法通常是不要一次加载所有可以加载的内容。因此,需要获取没有parentID的根节点或主题。然后将它们添加到trees根节点,然后对于添加的每个节点,需要获取其子节点
foreach (DataRow row in topicsWithOutParents.Rows)
{
TreeNode node = New TreeNode(... whatever);
DataSet childNodes = GetRowsWhereParentIDEquals(row["topicId"]);
foreach (DataRow child in childNodes.Rows)
{
Treenode childNode = new TreeNode(..Whatever);
node.Nodes.add(childNode);
}
Tree.Nodes.Add(node);
}
若并没有大量数据,那个么对于子节点/子节点,连接数据库、获取数据并一次又一次地添加到treeview节点是不好的。它可以一次完成。见以下示例:
这段代码对我来说运行得非常好,请查看,我认为它将帮助您: )
这段代码对我来说运行得很好。我认为它可能对希望在树视图中显示层次数据的人有用。到目前为止,我想这是最简单的。请检查一下,如果对你有帮助,请投票 参考: C代码:
//dtTree should be accessible in both page load and AddNodes()
//DocsMenu is the treeview Id
DataTable dtTree = new DataTable();
//declare your connection string
protected void Page_Load(object sender, EventArgs e)
{
//DataTable dtTree = new DataTable();
using (con)
{
con.Open();
string sQuery = "Select topicId,parentid,name from tbl_topicMaster";
SqlCommand cmd = new SqlCommand(sQuery, con);
cmd.CommandType = CommandType.Text;
SqlDataAdapter da = new SqlDataAdapter(cmd);
da.Fill(dtTree);
da.Dispose();
con.Close();
}
AddNodes(-1, DocsMenu.Nodes);
}
void AddNodes(int id, TreeNodeCollection tn)
{
foreach (DataRow dr in dtTree.Select("parentid= " + id))
{
TreeNode sub = new TreeNode(dr["name"].ToString(), dr["topicId"].ToString());
tn.Add(sub);
AddNodes(Convert.ToInt32(sub.Value), sub.ChildNodes);
}
}
aspx代码:
<asp:TreeView ID="DocsMenu" runat="server" ImageSet="BulletedList"
NodeIndent="15" >
<HoverNodeStyle Font-Underline="True" ForeColor="#6666AA" />
<NodeStyle Font-Names="Tahoma" Font-Size="8pt" ForeColor="Black" HorizontalPadding="2px"
NodeSpacing="0px" VerticalPadding="2px"></NodeStyle>
<ParentNodeStyle Font-Bold="False" />
<SelectedNodeStyle BackColor="#B5B5B5" Font-Underline="False" HorizontalPadding="0px"
VerticalPadding="0px" />
</asp:TreeView>
老帖子,但是很有用。无论如何,在单击节点时如何获取值?干杯
//dtTree should be accessible in both page load and AddNodes()
//DocsMenu is the treeview Id
DataTable dtTree = new DataTable();
//declare your connection string
protected void Page_Load(object sender, EventArgs e)
{
//DataTable dtTree = new DataTable();
using (con)
{
con.Open();
string sQuery = "Select topicId,parentid,name from tbl_topicMaster";
SqlCommand cmd = new SqlCommand(sQuery, con);
cmd.CommandType = CommandType.Text;
SqlDataAdapter da = new SqlDataAdapter(cmd);
da.Fill(dtTree);
da.Dispose();
con.Close();
}
AddNodes(-1, DocsMenu.Nodes);
}
void AddNodes(int id, TreeNodeCollection tn)
{
foreach (DataRow dr in dtTree.Select("parentid= " + id))
{
TreeNode sub = new TreeNode(dr["name"].ToString(), dr["topicId"].ToString());
tn.Add(sub);
AddNodes(Convert.ToInt32(sub.Value), sub.ChildNodes);
}
}
<asp:TreeView ID="DocsMenu" runat="server" ImageSet="BulletedList"
NodeIndent="15" >
<HoverNodeStyle Font-Underline="True" ForeColor="#6666AA" />
<NodeStyle Font-Names="Tahoma" Font-Size="8pt" ForeColor="Black" HorizontalPadding="2px"
NodeSpacing="0px" VerticalPadding="2px"></NodeStyle>
<ParentNodeStyle Font-Bold="False" />
<SelectedNodeStyle BackColor="#B5B5B5" Font-Underline="False" HorizontalPadding="0px"
VerticalPadding="0px" />
</asp:TreeView>