FieldEQ class

Implements the EQ field.

To learn more, visit the Working with Fields documentation article.

public class FieldEQ : Field


FieldEQ()The default constructor.


DisplayResult { get; }Gets the text that represents the displayed field result.
End { get; }Gets the node that represents the field end.
Format { get; }Gets a FieldFormat object that provides typed access to field’s formatting.
IsDirty { get; set; }Gets or sets whether the current result of the field is no longer correct (stale) due to other modifications made to the document.
IsLocked { get; set; }Gets or sets whether the field is locked (should not recalculate its result).
LocaleId { get; set; }Gets or sets the LCID of the field.
Result { get; set; }Gets or sets text that is between the field separator and field end.
Separator { get; }Gets the node that represents the field separator. Can be null.
Start { get; }Gets the node that represents the start of the field.
virtual Type { get; }Gets the Microsoft Word field type.


AsOfficeMath()Returns Office Math object corresponded to the EQ field.
GetFieldCode()Returns text between field start and field separator (or field end if there is no separator). Both field code and field result of child fields are included.
GetFieldCode(bool)Returns text between field start and field separator (or field end if there is no separator).
Remove()Removes the field from the document. Returns a node right after the field. If the field’s end is the last child of its parent node, returns its parent paragraph. If the field is already removed, returns null.
Unlink()Performs the field unlink.
Update()Performs the field update. Throws if the field is being updated already.
Update(bool)Performs a field update. Throws if the field is being updated already.


Shows how to replace the EQ field with Office Math.

Document doc = new Document(MyDir + "Field sample - EQ.docx");
FieldEQ fieldEQ = doc.Range.Fields.OfType<FieldEQ>().First();

OfficeMath officeMath = fieldEQ.AsOfficeMath();

fieldEQ.Start.ParentNode.InsertBefore(officeMath, fieldEQ.Start);

doc.Save(ArtifactsDir + "Field.EQAsOfficeMath.docx");

Shows how to use the EQ field to display a variety of mathematical equations.

public void FieldEQ()
    Document doc = new Document();
    DocumentBuilder builder = new DocumentBuilder(doc);

    // An EQ field displays a mathematical equation consisting of one or many elements.
    // Each element takes the following form: [switch][options][arguments].
    // There may be one switch, and several possible options.
    // The arguments are a set of coma-separated values enclosed by round braces.

    // Here we use a document builder to insert an EQ field, with an "\f" switch, which corresponds to "Fraction".
    // We will pass values 1 and 4 as arguments, and we will not use any options.
    // This field will display a fraction with 1 as the numerator and 4 as the denominator.
    FieldEQ field = InsertFieldEQ(builder, @"\f(1,4)");

    Assert.AreEqual(@" EQ \f(1,4)", field.GetFieldCode());

    // One EQ field may contain multiple elements placed sequentially.
    // We can also nest elements inside one another by placing the inner elements
    // inside the argument brackets of outer elements.
    // We can find the full list of switches, along with their uses here:

    // Below are applications of nine different EQ field switches that we can use to create different kinds of objects. 
    // 1 -  Array switch "\a", aligned left, 2 columns, 3 points of horizontal and vertical spacing:
    InsertFieldEQ(builder, @"\a \al \co2 \vs3 \hs3(4x,- 4y,-4x,+ y)");

    // 2 -  Bracket switch "\b", bracket character "[", to enclose the contents in a set of square braces:
    // Note that we are nesting an array inside the brackets, which will altogether look like a matrix in the output.
    InsertFieldEQ(builder, @"\b \bc\[ (\a \al \co3 \vs3 \hs3(1,0,0,0,1,0,0,0,1))");

    // 3 -  Displacement switch "\d", displacing text "B" 30 spaces to the right of "A", displaying the gap as an underline:
    InsertFieldEQ(builder, @"A \d \fo30 \li() B");

    // 4 -  Formula consisting of multiple fractions:
    InsertFieldEQ(builder, @"\f(d,dx)(u + v) = \f(du,dx) + \f(dv,dx)");

    // 5 -  Integral switch "\i", with a summation symbol:
    InsertFieldEQ(builder, @"\i \su(n=1,5,n)");

    // 6 -  List switch "\l":
    InsertFieldEQ(builder, @"\l(1,1,2,3,n,8,13)");

    // 7 -  Radical switch "\r", displaying a cubed root of x:
    InsertFieldEQ(builder, @"\r (3,x)");

    // 8 -  Subscript/superscript switch "/s", first as a superscript and then as a subscript:
    InsertFieldEQ(builder, @"\s \up8(Superscript) Text \s \do8(Subscript)");

    // 9 -  Box switch "\x", with lines at the top, bottom, left and right of the input:
    InsertFieldEQ(builder, @"\x \to \bo \le \ri(5)");

    // Some more complex combinations.
    InsertFieldEQ(builder, @"\a \ac \vs1 \co1(lim,n→∞) \b (\f(n,n2 + 12) + \f(n,n2 + 22) + ... + \f(n,n2 + n2))");
    InsertFieldEQ(builder, @"\i (,,  \b(\f(x,x2 + 3x + 2))) \s \up10(2)");
    InsertFieldEQ(builder, @"\i \in( tan x, \s \up2(sec x), \b(\r(3) )\s \up4(t) \s \up7(2)  dt)");

    doc.Save(ArtifactsDir + "Field.EQ.docx");

/// <summary>
/// Use a document builder to insert an EQ field, set its arguments and start a new paragraph.
/// </summary>
private static FieldEQ InsertFieldEQ(DocumentBuilder builder, string args)
    FieldEQ field = (FieldEQ)builder.InsertField(FieldType.FieldEquation, true);

    return field;

See Also