开发人员融合 [ ^ ]自动翻译了它(一旦我在Nodes.Clear之后立即更正了评论)

Developer fusion[^] auto translated it (once I had corrected the comment immediately after the Nodes.Clear)

DataSet DSNWind = null;
System.Data.SqlClient.SqlConnection CNnwind = new System.Data.SqlClient.SqlConnection("DATA SOURCE=Server;USER ID=sa;INITIAL CATALOG=northwind;");
//<==== CHANGE HERE 
System.Data.SqlClient.SqlDataAdapter DACustomers = new System.Data.SqlClient.SqlDataAdapter("SELECT CustomerID, CompanyName, ContactName, Country FROM customers WHERE country = 'Germany'", CNnwind);
System.Data.SqlClient.SqlDataAdapter DAOrders = new System.Data.SqlClient.SqlDataAdapter("SELECT CustomerID, OrderID, OrderDate, ShippedDate, ShipVia, Freight FROM orders where customerid in (select customerid from customers where country = 'Germany')", CNnwind);
System.Data.SqlClient.SqlDataAdapter DAOrderDetails = new System.Data.SqlClient.SqlDataAdapter("Select * from [Order Details] where OrderID in (SELECT OrderID FROM orders where customerid in (select customerid from customers where country = 'Germany'))", CNnwind);

DSNWind = new DataSet();
CNnwind.Open();
DACustomers.Fill(DSNWind, "dtCustomers");
DAOrders.Fill(DSNWind, "dtOrders");
DAOrderDetails.Fill(DSNWind, "dtOrderDetails");
//Close the connection to the data store; free up the resources
CNnwind.Close();

//Create a data relation object to facilitate the relationship between the Customers and Orders data tables.
DSNWind.Relations.Add("CustToOrd", DSNWind.Tables["dtCustomers"].Columns["CustomerID"], DSNWind.Tables["dtOrders"].Columns["CustomerID"]);
DSNWind.Relations.Add("OrdToDet", DSNWind.Tables["dtOrders"].Columns["OrderID"], DSNWind.Tables["dtOrderdetails"].Columns["OrderID"]);
///''''''''''''''''''''
TreeView1.Nodes.Clear();
////Dim i, n As Integer
DataRow parentrow = null;
DataTable ParentTable = null;
ParentTable = DSNWind.Tables["dtCustomers"];
foreach (DataRow parentrow_loopVariable in ParentTable.Rows) {
	parentrow = parentrow_loopVariable;
	TreeNode parentnode = default(TreeNode);
	parentnode = new TreeNode(parentrow[0]);
	TreeView1.Nodes.Add(parentnode);
	///'populate child'''''
	///''''''''''''''''''''
	DataRow childrow = null;
	TreeNode childnode = default(TreeNode);
	childnode = new TreeNode();
	foreach (DataRow childrow_loopVariable in parentrow.GetChildRows("CustToOrd")) {
		childrow = childrow_loopVariable;
		childnode = parentnode.Nodes.Add(childrow[0] + " " + childrow[1] + " " + childrow[2]);
		childnode.Tag = childrow["OrderID"];
		///'populate child2''''
		///'''''''''''''''''''''''
		DataRow childrow2 = null;
		TreeNode childnode2 = default(TreeNode);
		childnode2 = new TreeNode();
		foreach (DataRow childrow2_loopVariable in childrow.GetChildRows("OrdToDet")) {
			childrow2 = childrow2_loopVariable;
			childnode2 = childnode.Nodes.Add(childrow2[0]);

		}
		///'''''''''''''''''''''

	}
	///''''''''''''
}

它显示一条错误消息无法从对象"转换为字符串".

It is showing an error message "Cannot convert from ''object'' to ''string''.

.NET代码转换-转换代码 [