winform treeview递归加载数据库怎么实现

来源：恒创科技编辑：恒创科技编辑部

2024-04-01 14:24:24

在Winform中，可以通过递归方式加载数据库数据到TreeView中。下面是一个简单的示例代码：

首先，创建一个TreeView控件和一个Button控件：

TreeView treeView1 = new TreeView();
Button button1 = new Button();
button1.Text = "Load Data";
button1.Click += Button1_Click;

然后，在Button的Click事件中编写递归加载数据库数据的代码：

private void Button1_Click(object sender, EventArgs e)
{
    treeView1.Nodes.Clear(); // 清空TreeView节点

    // 连接数据库并查询数据
    using (SqlConnection conn = new SqlConnection("YourConnectionString"))
    {
        conn.Open();
        SqlCommand cmd = new SqlCommand("SELECT * FROM YourTable", conn);
        SqlDataReader reader = cmd.ExecuteReader();

        // 递归加载数据到TreeView中
        while (reader.Read())
        {
            LoadDataToTreeView(treeView1.Nodes, reader);
        }
    }
}

private void LoadDataToTreeView(TreeNodeCollection nodes, SqlDataReader reader)
{
    TreeNode node = new TreeNode(reader["ColumnName"].ToString());
    nodes.Add(node);

    // 递归加载子节点数据
    using (SqlConnection conn = new SqlConnection("YourConnectionString"))
    {
        conn.Open();
        SqlCommand cmd = new SqlCommand("SELECT * FROM YourTable WHERE ParentID = @ID", conn);
        cmd.Parameters.AddWithValue("@ID", reader["ID"]);
        SqlDataReader subReader = cmd.ExecuteReader();

        while (subReader.Read())
        {
            LoadDataToTreeView(node.Nodes, subReader);
        }
    }
}