C＃错误在DataGridView中显示Xml元素

Question

代码的目的是读取xml元素并显示datagridview中相关列名下的每个元素。

所以，我在这里有我的代码：

            IEnumerable<XElement> tables = xelement.Elements(df + "Table");
            foreach (XElement table in tables)
            {
                //Get name from TableName node
                XElement tableNameNode = table.Element(df + "TableName");
                tbTableName.Text = tableNameNode.Value.ToString();
                XElement numberRows = table.Element(df + "NumberOfRows");
                tbNumRows.Text = numberRows.Value.ToString();
                string tableName = tableNameNode.Value;

                TableData td = new TableData(CurrentProject.CurrentSchema.FindTable(tableName));
                td.PopulateFieldData();
               // tableDataList.TryGetValue(tableName, out td);
                tableDataList.Add(tableName, td);
                //If you open the project after you save it or open it, exception throws: Already Added Key!


                IEnumerable<XElement> fields = table.Elements(df + "Field");
                foreach (XElement field in fields)
                {
                    XElement fieldNameNode = field.Element(df + "Name");
                    string fieldName = fieldNameNode.Value;
                    FieldData fd = td.FieldList[fieldName];

                    IEnumerable<XElement> fieldProps = field.Descendants();
                    foreach (XElement fieldProp in fieldProps)
                    {
                        string fieldPropertyName = fieldProp.Name.ToString();
                        if (fieldPropertyName == "Name")
                        {
                            fd.Name = fieldProp.Value;
                        }

                        if (fieldPropertyName == "Type")
                        {
                            fd.DataType = fieldProp.Value;
                        }

                        if (fieldPropertyName == "Size")
                        {
                            int i = 0;
                            int.TryParse(fieldProp.Value.ToString(), out i);
                            fd.Size = i;
                        }

                        if (fieldPropertyName == "Nullable")
                        {
                            if (fieldProp.Value.ToString() == "True")
                                fd.Nullable = true;
                            else
                                fd.Nullable = false;
                        }

                        if (fieldPropertyName == "ContentSource")
                        {
                            fd.contentSource = fieldProp.Value;
                        }

                        if (fieldPropertyName == "ConstantValue")
                        {
                            fd.constantValue = fieldProp.Value;
                        }

                        if (fieldPropertyName == "RandomValue")
                        {
                            fd.averageSize = fieldProp.Value;
                        }

                        if (fieldPropertyName == "List")
                        {
                            fd.pickList = fieldProp.Value;
                        }
                     }
                    dataGridView1.Rows.Add(fd.Name, fd.DataType, fd.Size, fd.Nullable);


                    string ColumnName = dataGridView1.CurrentRow.Cells[0].Value.ToString();


                    this.tableDataList.TryGetValue(tbTableName.Text, out td);
                    if (td != null)
                    {
                        td.FieldList.TryGetValue(ColumnName, out fd);
                    }
                    foreach (var fdl in td.FieldList)
                    {

                         if (td != null && fd != null)
                    {
                        if (fd.contentSource == "Constant")
                        {
                            dataGridView1.CurrentRow.Cells[4].Value = fd.contentSource + "(" + "Value= " + fd.constantValue + ")";

                        }
                        if (fd.contentSource == "List")
                        {
                            dataGridView1.CurrentRow.Cells[4].Value = fd.contentSource + "(" + fd.pickList + ")";

                        }
                        if (fd.contentSource == "Random")
                        {
                            dataGridView1.CurrentRow.Cells[4].Value = fd.contentSource + "(" + fd.averageSize + ")";
                            }
                        }
                    }

                }
            }

这是我正在阅读的Xm​​l文件：

<?xml version="1.0"?>

<GeneratorXml>

<SchemaPath>C:\Projects\CoreSchema.xml</SchemaPath>

<GroupName>Documents</GroupName>


-<Table>

<TableName>directory</TableName>

<NumberOfRows>33</NumberOfRows>


-<Field>

<Name>dir_id</Name>

<Type>number</Type>

<Size>10</Size>

<Nullable>False</Nullable>

<ContentSource>Random</ContentSource>

<ConstantValue> </ConstantValue>

<RandomValue>4</RandomValue>

<List> </List>

</Field>


-<Field>

<Name>directory_number</Name>

<Type>number</Type>

<Size>5</Size>

<Nullable>False</Nullable>

<ContentSource>List</ContentSource>

<ConstantValue> </ConstantValue>

<RandomValue> </RandomValue>

<List>Coffee</List>

</Field>


-<Field>

<Name>file_count</Name>

<Type>number</Type>

<Size>5</Size>

<Nullable>False</Nullable>

<ContentSource>Constant</ContentSource>

<ConstantValue>2</ConstantValue>

<RandomValue> </RandomValue>

<List> </List>

</Field>


+<Field>

</Table>

</GeneratorXml>

当我运行代码时，我只得到这个GridView：

我认为我的for循环遇到了问题，但我找不到它。提前感谢您的每一个想法。