如何从Flutter TextBox获取原始文本

Question

在Flutter中，在放置Paragraph或TextPainter的文本后，可以通过调用getBoxesForSelection获取行的Rect（或在行中运行）。如果绘制实际的框，则它们看起来像这样：

如何以编程方式在每个TextBox中获取文本？

Answer 1

我希望有更好的方法，但这是到目前为止我发现的唯一方法：

// 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);

注意：

• 要想更努力，请检查TextPosition affinity。
• 这还不能处理从右到左的文本。