It looks like you're missing two key pieces in your current code that are preventing you from adjusting the legend's font size and line spacing: you haven't attached your configured TextProperties to the Legend object, and you haven't explicitly set the font size and line spacing values in the paragraph/run properties. Let's fix that step by step.

Key Issues in Your Current Code #

• The textPros object you created isn't being added to the legend2 element—so none of your text styling is actually being applied to the legend.
• You haven't defined concrete values for font size or line spacing in your paragraph/run properties.

Modified Code with Fixes #

Here's the updated version of your CreateChart method that properly applies smaller font size and tighter line spacing to the legend:

public void CreateChart(List<ChartSubArea> chartList, string variable, string id) {
    dc.Legend legend2 = new dc.Legend();
    dc.LegendPosition legendPosition2 = new dc.LegendPosition() { val = dc.LegendPositionValues.Right };
    dc.Overlay overlay3 = new dc.Overlay() { Val = false };
    legend2.Append(legendPosition2);
    legend2.Append(overlay3);

    // Configure text properties for legend
    dc.TextProperties textPros = new dc.TextProperties();
    textPros.Append(new d.BodyProperties());
    textPros.Append(new d.ListStyle());

    d.Paragraph paragraph = new d.Paragraph();
    d.ParagraphProperties paraPros = new d.ParagraphProperties();
    d.DefaultParagraphProperties defaultParaPros = new d.DefaultParagraphProperties();

    // Set font to Arial, and add font size (8pt = 16 half-points)
    defaultParaPros.Append(new d.LatinFont() { Typeface = "Arial", PitchFamily = 34, CharacterSet = 0 });
    defaultParaPros.Append(new d.ComplexScriptFont() { Typeface = "Arial", PitchFamily = 34, CharacterSet = 0 });
    d.DefaultRunProperties defaultRunProps = new d.DefaultRunProperties() { FontSize = 16 }; // 8pt font
    defaultParaPros.Append(defaultRunProps);

    // Set tight line spacing (10pt line height = 200 twentieths of a point)
    d.Spacing spacing = new d.Spacing() { Line = 200, LineRule = d.LineSpacingRuleValues.Auto };
    defaultParaPros.Append(spacing);

    paraPros.Append(defaultParaPros);
    paragraph.Append(paraPros);
    paragraph.Append(new d.EndParagraphRunProperties() { Language = "en-Us" });

    textPros.Append(paragraph);
    // Critical: Attach the text properties to the legend
    legend2.Append(textPros);
}

What Changed? #

1. Attached TextProperties to Legend: We added legend2.Append(textPros); so your styling is actually applied to the legend element.
2. Added Font Size: The DefaultRunProperties with FontSize = 16 sets the text to 8pt (OpenXML uses half-point units for font size). Adjust this value (e.g., 14 for 7pt, 12 for 6pt) if you need even smaller text.
3. Added Tight Line Spacing: The Spacing element with Line = 200 sets the line height to 10pt (units are twentieths of a point). Lower this value (like 180 for 9pt) to tighten spacing further.

Additional Notes #

• If the legend is still truncated, try reducing the FontSize value incrementally (e.g., down to 12 for 6pt) or decreasing the Line value in the Spacing element.
• Make sure you're using the correct OpenXML namespace aliases (dc for DocumentFormat.OpenXml.Drawing.Charts, d for DocumentFormat.OpenXml.Drawing) to avoid compilation errors.

内容的提问来源于stack exchange，提问作者Faiza Nasir