如何限制串联的参数数量?

Question

程序的想法是连接不同的参数并将其全部放在另一个参数中。如何让最终用户决定是否要连接 2 个或 3 个参数。现在就像你不输入 3 个参数一样，它将无法工作。我想出的任何东西都没有奏效。

namespace CombineParametersWinForm
{
public partial class Form1 : System.Windows.Forms.Form

{
//Class variable 
Document revitDoc { get; set; }

public Form1(Document doc)
{
InitializeComponent();

this.revitDoc = doc;
//Create a list of the parameters you want your user to choose from 
List<string> stringParameters = new List<string>
{
"Weight",
"Angle",
"Manufacturer"
};
//Add list to comboboxes on form 
foreach (string parameterName in stringParameters)
{
comboBox1.Items.Insert(0, parameterName);
comboBox2.Items.Insert(0, parameterName);
comboBox3.Items.Insert(0, parameterName);
}

}

private void button1_Click(object sender, EventArgs e)
{
FilteredElementCollector collector = new FilteredElementCollector(revitDoc);
ElementCategoryFilter filter = new ElementCategoryFilter(BuiltInCategory.OST_PipeFitting);
//Applying Filter
IList<Element> ducts = collector.WherePasses(filter).WhereElementIsNotElementType().ToElements();
foreach (Element duct in ducts)
{
//Get Parameter values
string parameterValue1 = duct.LookupParameter(comboBox1.Text).AsValueString();
string parameterValue2 = duct.LookupParameter(comboBox2.Text).AsValueString();
string parameterValue3 = duct.LookupParameter(comboBox3.Text).AsValueString();

string newValue = parameterValue1 + "-" + parameterValue2 + "-" + parameterValue3;

//do not need .ToString() when setting parameter

using (Transaction t = new Transaction(revitDoc, "Set Parameter name"))
{
t.Start();
duct.LookupParameter("New").Set(newValue);
t.Commit();
}

想法。第一个是相当长的。

string parameterValue1 = duct.LookupParameter(comboBox1.Text).AsValueString();
string parameterValue2 = duct.LookupParameter(comboBox2.Text).AsValueString();
string parameterValue3 = duct.LookupParameter(comboBox3.Text).AsValueString();

if (parameterValue1 != "" || parameterValue1 != null)
{
parameterValue1 = parameterValue11;
}
if (parameterValue2 != "" || parameterValue2 != null)
{
parameterValue1 = parameterValue22;
}
if (parameterValue3 != "" || parameterValue3 != null)
{
parameterValue3 = parameterValue33;
}

if (parameterValue1 == "" || parameterValue1 == null)
{
parameterValue11 = "";
}
if (parameterValue2 == "" || parameterValue2 == null)
{
parameterValue22 = "";
}
if (parameterValue3 == "" || parameterValue3 == null)
{
parameterValue33 = "";
}
string newValue = parameterValue1 + "-" + parameterValue2 + "-" + parameterValue3;
using (Transaction t = new Transaction(revitDoc, "Set Parameter name"))
{
t.Start();
duct.LookupParameter("New").Set(newValue);
t.Commit();
}
}

}
}
}

第二个是短的，但仍然不起作用

string parameterValue1 = duct.LookupParameter(comboBox1.Text).AsValueString();
string parameterValue2 = duct.LookupParameter(comboBox2.Text).AsValueString();
string parameterValue3 = duct.LookupParameter(comboBox3.Text).AsValueString();

List<string> listParam = new List<string> { parameterValue1, parameterValue2, parameterValue3 };
foreach (string s in listParam)
{
if (s != "" /*&& s != null*/)
{
List<string> listParamNotNull = new List<string> { s };
string newValue = String.Join(" ,", listParamNotNull);

using (Transaction t = new Transaction(revitDoc, "Set Parameter name"))
{
t.Start();
duct.LookupParameter("New").Set(newValue);
t.Commit();
}

Answer 1

您正在创建三个单独的List，并希望对所有这些组合执行某些操作，但实际上分别对每个执行操作，并随手覆盖。

请仔细查看您的嵌套逻辑。

这样的东西可能更合适：

using System;
using System.Collections.Generic;

public class Program
{
public static void Main()
{
string parameterValue1 = "Value1";
string parameterValue2 = ""; // purposefully providing an empty value
string parameterValue3 = "Value3";
var listParamIn = new List<string> { parameterValue1, parameterValue2, parameterValue3 };
var listParamOut = new List<string>();
foreach (string s in listParamIn){
if (string.IsNullOrEmpty(s))
continue;

listParamOut.Add(s);
}

string newValue = String.Join(", ", listParamOut);
Console.WriteLine(newValue);
/* continue with your transaction
using (Transaction t = new Transaction(revitDoc, "Set Parameter name")){
t.Start();
duct.LookupParameter("New").Set(newValue);
t.Commit();
}
*/
}
}

输出：

值 1， 值 3

看： https://dotnetfiddle.net/mXdL5F