dataRow out of context error in datatable c#

Question

Below is my code and I am getting out of context error for workRow variable, please resolve this issue I tried everything like written separate function to add row . . that is not helping me . . only (reader.Name == "Result") I want to create roe and in other if want to add columns in that same row

while (reader.Read())
{
    switch (reader.NodeType)
    {
        case XmlNodeType.Element:
           if (reader.Name == "Result")
           {
              DataRow workRow = dt.NewRow();
           }               
           if (columns.Contains(reader.Name))
           {
              //ERROR IS HERE out of context
              workRow[reader.Name] = reader.Value;
           }
           writer.WriteStartElement(reader.Name);
           break;
       case XmlNodeType.Text:
           writer.WriteString(reader.Value);
           break;
       case XmlNodeType.XmlDeclaration:
       case XmlNodeType.ProcessingInstruction:  
           writer.WriteProcessingInstruction(reader.Name, reader.Value);
           break;
       case XmlNodeType.Comment:
           writer.WriteComment(reader.Value);
           break;
       case XmlNodeType.EndElement:
           writer.WriteFullEndElement();
           break;
    }
}

Answer 1

Youre workRow variable is declared inside another if statement that's why you're getting that error.

DataRow workRow; // Moved the declaration here
while (reader.Read())
{
    switch (reader.NodeType)
    {
        case XmlNodeType.Element:
            if (reader.Name == "Result")
            {
                workRow = dt.NewRow(); // this is okay if Result always comes first
            }

            if (columns.Contains(reader.Name))
            {
                //ERROR IS HERE out of context
                workRow[reader.Name] = reader.Value;
            }
            writer.WriteStartElement(reader.Name);
            break;
        case XmlNodeType.Text:
            writer.WriteString(reader.Value);
            break;
        case XmlNodeType.XmlDeclaration:
        case XmlNodeType.ProcessingInstruction:
            writer.WriteProcessingInstruction(reader.Name, reader.Value);
            break;
        case XmlNodeType.Comment:
            writer.WriteComment(reader.Value);
            break;
        case XmlNodeType.EndElement:
            writer.WriteFullEndElement();
            break;
    }
}

Answer 2

Please declare workRow outside if or add your workRow[reader.Name] inside first if as shown below. The problem is you are scoping your workRow variable within the if (reader.Name == "Result") , so when you try to access workRow outside this if block you will get error. Please check sample modification that may work for you

 if (reader.Name == "Result")
 {
     DataRow workRow = dt.NewRow();

     //Just a suggestion
     if (columns.Contains(reader.Name))
     {
          workRow[reader.Name] = reader.Value;
     }
 }

Answer 3

Declare workflow to inner of correct if statement like below.

if (reader.Name == "Result")
   {
       //DataRow workRow = dt.NewRow();
   }
if (columns.Contains(reader.Name))
   {
       DataRow workRow = dt.NewRow();
       //ERROR IS HERE out of context
       workRow[reader.Name] = reader.Value;
   }