Question

我正在使用TextFormatter制作WPF文本编辑器。我需要缩进一些段落，所以我使用TextParagraphProperties类中的Indent属性。

在这种情况下，这很有效：

没有任何
的常规文本压痕。
本段有统一的缩进所以一切都是 ok了。

但我也需要这个：
约翰：这一段有一个不同的缩进
在第一行。
乔：所以我不知道如何实现这一目标
我找到了ParagraphIndent和FirstLineInParagraph属性，但我不知道它们是如何工作的，或者当时是否有用。

提前致谢!! 何

Answer 1

何塞 -

希望这段代码框架有所帮助......我假设你是从MSDN上的高级文本格式化项目开始的，遗憾的是它不是很先进。这是一个可以引入MainWindow.Xaml.cs的代码片段：

        TextParagraphProperties textParagraphProperties = new GenericTextParagraphProperties(TextAlignment.Left,
                                                                                             false);
        TextRunCache textRunCache = new TextRunCache();

        // By default, this is the first line of a paragrph
        bool firstLine = true;
        while (textStorePosition < _textStore.Length)
        {
            // Create a textline from the text store using the TextFormatter object.
            TextLine myTextLine = formatter.FormatLine(
                _textStore,
                textStorePosition,
                96 * 6,

                // ProxyTextParagraphProperties will return a different value for the Indent property,
                // depending on whether firstLine is true or not.
                new ProxyTextParagraphProperties(textParagraphProperties, firstLine),
                lastLineBreak,
                textRunCache);

            // Draw the formatted text into the drawing context.
            Debug.WriteLine("linePosition:" + linePosition);
            myTextLine.Draw(dc, linePosition, InvertAxes.None);

            // Update the index position in the text store.
            textStorePosition += myTextLine.Length;

            // Update the line position coordinate for the displayed line.
            linePosition.Y += myTextLine.Height;

            // Figure out if the next line is the first line of a paragraph
            var textRunSpans = myTextLine.GetTextRunSpans();
            firstLine = (textRunSpans.Count > 0) && (textRunSpans[textRunSpans.Count - 1].Value is TextEndOfParagraph);

            lastLineBreak = myTextLine.GetTextLineBreak();
        }

您需要创建ProxyTextParagraphProperties类，它来自TextParagraphProperties。以下是我测试此内容的一小部分：

class ProxyTextParagraphProperties : TextParagraphProperties
{
    private readonly TextParagraphProperties _paragraphProperties;
    private readonly bool _firstLineInParagraph;

    public ProxyTextParagraphProperties(TextParagraphProperties textParagraphProperties, bool firstLineInParagraph)
    {
        _paragraphProperties = textParagraphProperties;
        _firstLineInParagraph = firstLineInParagraph;
    }

    public override FlowDirection FlowDirection
    {
        get { return _paragraphProperties.FlowDirection; }
    }

    // implement the same as above for all the other properties...

    // But we need to handle this one specially...
    public override double Indent
    {
        get
        {
            return _firstLineInParagraph ? _paragraphProperties.Indent : 0;
        }
    }
}

WPF TextFormatter中的缩进

1 个答案: