存储树形的数据表转为Json

/// <summary>
/// 根据DataTable生成Json树结构
/// </summary>
/// <param name="tabel">数据源</param>
/// <param name="idCol">ID列</param>
/// <param name="txtCol">Text列</param>
/// <param name="rela">关系字段</param>
/// <param name="pId">父ID</param>
StringBuilder result = new StringBuilder();
StringBuilder sb = new StringBuilder();
private void GetTreeJsonByTable(DataTable tabel, string idCol, string txtCol, string rela, object pId)
{
result.Append(sb.ToString());
sb.Clear();
if (tabel.Rows.Count > 0)
{
sb.Append("[");
string filer = string.Format("{0}='{1}'", rela, pId);
DataRow[] rows = tabel.Select(filer);
if (rows.Length > 0)
{
foreach (DataRow row in rows)
{
sb.Append("{\"id\":\"" + row[idCol] + "\",\"text\":\"" + row[txtCol] + "\",\"state\":\"open\"");
if (tabel.Select(string.Format("{0}='{1}'", rela, row[idCol])).Length > 0)
{
sb.Append(",\"children\":");
GetTreeJsonByTable(tabel, idCol, txtCol, rela, row[idCol]);
result.Append(sb.ToString());
sb.Clear();
}
result.Append(sb.ToString());
sb.Clear();
sb.Append("},");
}
sb = sb.Remove(sb.Length - 1, 1);
}
sb.Append("]");
result.Append(sb.ToString());
sb.Clear();
}
}