[英]how to abstract tree view node creation/ population?
我有以下代碼,我想將全局方法設置為static,以便可以在asp.net Web應用程序上構建幾個樹形視圖。 現在,我每個人都使用下面的代碼構建自己的樹形視圖。 我正在考慮制作一種全局靜態方法來生成諸如此類的節點結構,然后將其分配給我頁面中的樹形視圖……或類似的東西。 我會關心實際解決方案的細節,只要我可以有一個像“ buildTree()”這樣的方法就可以將樹視圖控件綁定到該方法。
艱難?
DataTable dtProjects = new DataTable();
DataTable dtRelease = new DataTable();
using (SqlConnection con = Global.GetConnection())
{
StringBuilder str = new StringBuilder();
str.Append("SELECT r.ReleaseId, ");
str.Append(" r.Name, ");
str.Append(" rs.EndDate ");
str.Append(" FROM Release r ");
str.Append(" LEFT OUTER JOIN ReleaseSchedule rs ");
str.Append(" ON r.ReleaseId = rs.ReleaseId ");
str.Append(" AND rs.MilestoneCID = 77");
str.Append(" WHERE r.CompletionStatusCID NOT IN (34, 35) ");
str.Append(" ORDER BY r.ReportingPriority, r.Name ");
SqlDataAdapter da = new SqlDataAdapter(str.ToString(), con);
da.Fill(dtRelease);
str = new StringBuilder();
str.Append("SELECT p.ProjectId, ");
str.Append(" p.ProjectName, ");
str.Append(" p.ParentProjectId, ");
str.Append(" p.ReleaseId ");
str.Append(" FROM Project p ");
str.Append(" WHERE p.CompletionStatusCID NOT IN (34, 35) ");
str.Append(" AND p.ProjectTypeCID <> 92 ");
str.Append(" ORDER BY p.ProjectName ");
da = new SqlDataAdapter(str.ToString(), con);
da.Fill(dtProjects);
}
tvProject.Nodes.Clear();
TreeNode rootNode = new TreeNode("All Projects");
rootNode.Expanded = true;
foreach (DataRow drRelease in dtRelease.Rows)
{
TreeNode releaseNode = new TreeNode((string)drRelease["Name"]);
DataRow[] releaseProjects = dtProjects.Select("(ReleaseId = " + drRelease["ReleaseId"] + ") AND (ParentProjectId IS NULL)");
foreach (DataRow drProject in releaseProjects)
{
TreeNode projectNode = new TreeNode((string)drProject["ProjectName"], drProject["ProjectId"].ToString());
projectNode.ToolTip = "This is a project node and is selectable";
loadTVNode((int)drProject["ProjectId"], projectNode, dtProjects);
if (drRelease["EndDate"] != System.DBNull.Value)
{
string s = ((DateTime)drRelease["EndDate"]).ToString(Global.CONST_DateFormat);
releaseNode.ToolTip = "Release scheduled for deployment on " + s;
}
else
releaseNode.ToolTip = "Release deployment has not been scheduled";
releaseNode.ToolTip += ". This node is not selectable";
releaseNode.ChildNodes.Add(projectNode);
}
rootNode.ChildNodes.Add(releaseNode);
}
tvProject.Nodes.Add(rootNode);
我沒有立即得到這個問題,但是我想您正在尋找這樣的東西:
用一個公共方法創建一個名為TreeViewBuilder的類,以從現有的方法返回已填充的TreeView:
public class TreeViewBuilder
{
public static TreeView BuildTreeView( TreeView tree )
{
DataTable projects = GetProjects();
DataTable releases = GetRealeases();
return InternalTreeViewBuilder(tree, projects, releases);
}
}
我的猜測是,您可以在此解決方案中填補空白,例如傳遞所需的參數等等。 您還可以從放置在問題中的代碼中為要調用的樹方法構建代碼。 您的創建例程現在為:
//TreeView something;
TreeViewBuilder.BuildTreeView(something);
更酷的是,如果您使用的是.NET Framework 3.5以上版本,則可以將該方法作為擴展:
public static class TreeViewBuilder
{
public static TreeView BuildTreeView( this TreeView tree )
{
DataTable projects = GetProjects();
DataTable releases = GetRealeases();
return InternalTreeViewBuilder(tree, projects, releases);
}
}
然后,調用您的方法將變得更加簡單:
//TreeView something;
something.BuildTreeView();
完成了! MSDN有一些很棒的擴展方法代碼。
希望我能幫忙!
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