如何从 Flutter TextBox 中获取原始文本

How to get the raw text from a Flutter TextBox

在 Flutter 中,在 Paragraph 或 TextPainter 对其文本进行布局后,您可以通过调用 getBoxesForSelection 获取行(或行内运行)的 Rects。如果你绘制实际的盒子,它们看起来像这样:

如何以编程方式获取每个 TextBox 中的文本?

我希望有更好的方法,但这是目前我找到的唯一方法:

// The TextPaint has already been laid out

// select everything
TextSelection selection = TextSelection(baseOffset: 0, extentOffset: textSpan.text.length);

// get a list of TextBoxes (Rects)
List<TextBox> boxes = _textPainter.getBoxesForSelection(selection);

// Loop through each text box
List<String> lineTexts = [];
int start = 0;
int end;
int index = -1;
for (TextBox box in boxes) {
  index += 1;

  // Uncomment this if you want to only get the whole line of text
  // (sometimes a single line may have multiple TextBoxes)
  // if (box.left != 0.0)
  //  continue;

  if (index == 0)
    continue;
  // Go one logical pixel within the box and get the position
  // of the character in the string.
  end = _textPainter.getPositionForOffset(Offset(box.left + 1, box.top + 1)).offset;
  // add the substring to the list of lines
  final line = rawText.substring(start, end);
  lineTexts.add(line);
  start = end;
}
// get the last substring
final extra = rawText.substring(start);
lineTexts.add(extra);

备注:

  • 为了更加反驳,这应该检查TextPosition affinity
  • 这还不能处理 right-to-left 文本。

更新:

  • 如果您正在获取整行的文本,您现在可以使用 LineMetrics(来自 TextPainter.computeLineMetrics())而不是 TextBox。这个过程是相似的。