Spire.Doc组件为用户提供了多种域类型选择，其中涵盖了Word自带的各种域类型。这些域类型被定义在枚举Spire.Doc.FieldType中，下图为部分域类型及描述：

该文我们详细介绍如何使用Spire.Doc添加下面三种常见的word 域：FieldDate（日期域），FieldIf （条件域）及TOC（目录域）。

FieldDate （日期域）

//新建一个word文档对象
Document document = new Document();

//添加一个section和paragraph
Section section = document.AddSection();
Paragraph paragraph = section.AddParagraph();

//添加文本到paragraph
paragraph.AppendText("今天的日期为: ");

//添加日期域并设置日期格式
Field field = paragraph.AppendField("Date", FieldType.FieldData) as Field;
field.Code = @"DATE  \@" + "\"yyyy年MM月dd日 \"";

//保存文档
document.SaveToFile("Sample.docx", FileFormat.Docx2013);

'新建一个word文档对象
Dim document As Document = New Document
'添加一个section和paragraph
Dim section As Section = document.AddSection
Dim paragraph As Paragraph = section.AddParagraph
'添加文本到paragraph
paragraph.AppendText("今天的日期为: ")
'添加日期域并设置日期格式
Dim field As Field = CType(paragraph.AppendField("Date", FieldType.FieldData),Field)
field.Code = ("DATE  \@" + """yyyytMMdd  """"")
'保存文档
document.SaveToFile("Sample.docx", FileFormat.Docx2013)

FieldIf（条件域）

Spire.Doc创建条件域的时候，我们会用到两个域，一个是条件域，一个是邮件合并域。格式为这样{IF { MERGEFIELD Count } > "60" "成绩合格" "成绩不合格"}

{
   //新建一个word文档对象并添加section和paragraph
   Document document = new Document();
   Section section = document.AddSection();
   Paragraph paragraph = section.AddParagraph();

   //调用CreateIfField方法并赋值
   CreateIfField(document, paragraph);
   string[] fieldName = { "Count" };
   string[] fieldValue = { "100" };

//合并值到条件域
   document.MailMerge.Execute(fieldName, fieldValue);

//更新域
   document.IsUpdateFields = true;
 
 //保存文档
   document.SaveToFile("sample.docx", FileFormat.Docx); 
  }

 static void CreateIfField(Document document, Paragraph paragraph)
 {
  //添加条件域并设置条件
IfField ifField = new IfField(document);
ifField.Type = FieldType.FieldIf;

    ifField.Code = "IF ";
    paragraph.Items.Add(ifField);
    paragraph.AppendField("Count",FieldType.FieldMergeField);
    paragraph.AppendText(" > ");
    paragraph.AppendText("\"60\" ");
    paragraph.AppendText("\"成绩合格\" ");
    paragraph.AppendText("\"成绩不合格\"");
   IParagraphBase end = document.CreateParagraphItem(ParagraphItemType.FieldMark);
  (end as FieldMark).Type = FieldMarkType.FieldEnd;
   paragraph.Items.Add(end);
   ifField.End = end as FieldMark;
}

'新建一个word文档对象并添加section和paragraph
Dim document As Document = New Document
Dim section As Section = document.AddSection
Dim paragraph As Paragraph = section.AddParagraph
'调用CreateIfField方法并赋值
CreateIfField(document, paragraph)
Dim fieldName() As String
Dim fieldValue() As String
'合并值到条件域
document.MailMerge.Execute(fieldName, fieldValue)
'更新域
document.IsUpdateFields = true
'保存文档
document.SaveToFile("sample.docx", FileFormat.Docx)
    
    Private Shared Sub CreateIfField(ByVal document As Document, ByVal paragraph As Paragraph)
        '添加条件域并设置条件
        Dim ifField As IfField = New IfField(document)
        ifField.Type = FieldType.FieldIf
        ifField.Code = "IF "
        paragraph.Items.Add(ifField)
        paragraph.AppendField("Count", FieldType.FieldMergeField)
        paragraph.AppendText(" > ")
        paragraph.AppendText("""60"" ")
        paragraph.AppendText("\"成绩合格\" ")
        paragraph.AppendText("\"成绩不合格\"")
        Dim end As IParagraphBase = document.CreateParagraphItem(ParagraphItemType.FieldMark)
        CType(end,FieldMark).Type = FieldMarkType.FieldEnd
        paragraph.Items.Add(end)
        ifField.End = CType(end,FieldMark)
    End Sub

TOC（目录域）

Spire.Doc提供了AppendTOC()方法让用户能够直接添加目录域。

{
  //新建一个word文档对象并添加section和paragraph
Document document = new Document();
  Section section = document.AddSection();
  Paragraph paragraph = section.AddParagraph();

//添加目录域
  paragraph.AppendTOC(1, 3);

//添加内容到段落并设置样式
  Paragraph para1 = section.AddParagraph();
  para1.AppendText("Head1");
  para1.ApplyStyle(BuiltinStyle.Heading1);

  Paragraph para2 = section.AddParagraph();
  para2.AppendText("Head2");
  para2.ApplyStyle(BuiltinStyle.Heading2);

  //更新目录域
  document.UpdateTableOfContents();

//保存文档
  document.SaveToFile("TOC.docx", FileFormat.Docx);

  }

'新建一个word文档对象并添加section和paragraph
Dim document As Document = New Document
Dim section As Section = document.AddSection
Dim paragraph As Paragraph = section.AddParagraph
'添加目录域
paragraph.AppendTOC(1, 3)
'添加内容到段落并设置样式
Dim para1 As Paragraph = section.AddParagraph
para1.AppendText("Head1")
para1.ApplyStyle(BuiltinStyle.Heading1)
Dim para2 As Paragraph = section.AddParagraph
para2.AppendText("Head2")
para2.ApplyStyle(BuiltinStyle.Heading2)
'更新目录域
document.UpdateTableOfContents
'保存文档
document.SaveToFile("TOC.docx", FileFormat.Docx)