我想知道如何在WPF RichTextBox中获取当前光标所在的单词。我知道RichTextBox有Selection Property，但它只能给出在RichTextBox中选定的文本，而我想知道即使整个单词没有被选中，光标所在的单词。感谢任何建议。
5个回答
5
将此函数附加到任意RichTextBox上，现在称为testRTB，并查看输出窗口以获取结果：
private void testRTB_MouseUp(object sender, MouseButtonEventArgs e)
{
TextPointer start = testRTB.CaretPosition; // this is the variable we will advance to the left until a non-letter character is found
TextPointer end = testRTB.CaretPosition; // this is the variable we will advance to the right until a non-letter character is found
String stringBeforeCaret = start.GetTextInRun(LogicalDirection.Backward); // extract the text in the current run from the caret to the left
String stringAfterCaret = start.GetTextInRun(LogicalDirection.Forward); // extract the text in the current run from the caret to the left
Int32 countToMoveLeft = 0; // we record how many positions we move to the left until a non-letter character is found
Int32 countToMoveRight = 0; // we record how many positions we move to the right until a non-letter character is found
for (Int32 i = stringBeforeCaret.Length - 1; i >= 0; --i)
{
// if the character at the location CaretPosition-LeftOffset is a letter, we move more to the left
if (Char.IsLetter(stringBeforeCaret[i]))
++countToMoveLeft;
else break; // otherwise we have found the beginning of the word
}
for (Int32 i = 0; i < stringAfterCaret.Length; ++i)
{
// if the character at the location CaretPosition+RightOffset is a letter, we move more to the right
if (Char.IsLetter(stringAfterCaret[i]))
++countToMoveRight;
else break; // otherwise we have found the end of the word
}
start = start.GetPositionAtOffset(-countToMoveLeft); // modify the start pointer by the offset we have calculated
end = end.GetPositionAtOffset(countToMoveRight); // modify the end pointer by the offset we have calculated
// extract the text between those two pointers
TextRange r = new TextRange(start, end);
String text = r.Text;
// check the result
System.Diagnostics.Debug.WriteLine("[" + text + "]");
}
将Char.IsLetter(...)更改为Char.IsLetterOrDigit(...)或其他适当的内容，具体取决于您是否希望保留数字。
提示：将此提取到单独的程序集中作为扩展方法，以便在需要时访问它。
- Balázs
3
好的，为了解决这个问题，我使用暴力破解的方法。
我使用了
curCaret.GetTextInRun(LogicalDirection.Backward)
和
curCaret.GetTextInRun(LogicalDirection.Forward)
以及 preCaretString.LastIndexOf(" ") 和 postCaretString.IndexOf(" ") 这些分隔单词的字符，得到了子字符串。
最后，我将字符串的前半部分和后半部分相加，获得了当前光标所在的单词。
我相信还有更聪明的方法可以解决这个问题，但至少这种方法解决了问题。
- Shintaro Takechi
1
您可以通过 CaretPosition 获取光标的当前位置。
不幸的是，没有简单的方法来获取插入符号位置左侧/右侧的字符。我所知道的唯一从RichTextBox中获取文本的方法在this answer中，这有点复杂。但它可以完成必要的任务。
- ikh
2
非常感谢您的回复。我真的很感激您指出CaretPosition。然而，正如您所描述的那样，似乎没有简单的方法来确定光标所在单词的开头，因为Document.ContentStart和Document.ContentEnd指向句子的开头和结尾。也许我需要从TextPointer位置开始搜索空格。（但是对于没有空格以确定单独单词的2字节单词，我可能会遇到困难） - Shintaro Takechi
我猜这个问题已经存在一段时间了... http://stackoverflow.com/questions/10904614/extract-text-from-caret-position-textarea - Shintaro Takechi
-1
这是我使用LINQ和依赖属性的替代解决方案：
public class SelectionRichTextBox : RichTextBox
{
public SelectionRichTextBox()
{
// Use base class style
SetResourceReference(StyleProperty, typeof(RichTextBox));
}
public static readonly DependencyProperty SelectedWordProperty =
DependencyProperty.Register(
"SelectedWord",
typeof(string),
typeof(SelectionRichTextBox),
new PropertyMetadata("")
);
public string SelectedWord
{
get
{
return (string)GetValue(SelectedWordProperty);
}
set
{
SetValue(SelectedWordProperty, value);
}
}
protected override void OnMouseUp(MouseButtonEventArgs e)
{
TextPointer cursorPosition = CaretPosition;
string strBeforeCursor = cursorPosition.GetTextInRun(LogicalDirection.Backward);
string strAfterCursor = cursorPosition.GetTextInRun(LogicalDirection.Forward);
string wordBeforeCursor = strBeforeCursor.Split().Last();
string wordAfterCursor = strAfterCursor.Split().First();
string text = wordBeforeCursor + wordAfterCursor;
SelectedWord = string.Join("", text
.Where(c => char.IsLetter(c))
.ToArray());
base.OnMouseUp(e);
}
}
之后，您可以像这样在绑定中使用它：
<custom:SelectionRichTextBox
SelectedWord="{Binding SelectedWord, Mode=OneWayToSource}"/>
- NearHuscarl
-1
由于单词是由空格分隔的，因此您可以在插入符周围的运行中迭代，直到找到空格为止。即使您的RichTextBox包含不同的字体和字号，此函数也应该能够正常工作。
public string GetWordByCaret(LogicalDirection direction)
{
// Get the CaretPosition
TextPointer position = this.CaretPosition;
TextPointerContext context = position.GetPointerContext(direction);
string text = string.Empty;
// Iterate through the RichTextBox based on the Start, Text and End of nearby inlines
while (context != TextPointerContext.None)
{
// We are only interested in the text here
//, so ignore everything that is not text
if (context == TextPointerContext.Text)
{
string current = position.GetTextInRun(direction);
// The strings appended based on whether they are before the caret or after it...
// And well...I love switches :)
switch (direction)
{
case LogicalDirection.Backward:
{
int spaceIndex = current.LastIndexOf(' ');
// If space is found, we've reached the end
if (spaceIndex >= 0)
{
int length = current.Length - 1;
if (spaceIndex + 1 <= length)
{
text = current.Substring(spaceIndex + 1, length - spaceIndex) + text;
}
return text;
}
else
text = current + text;
}
break;
default:
{
int spaceIndex = current.IndexOf(' ');
// If space is found, we've reached the end
if (spaceIndex >= 0)
{
int length = current.Length;
if (spaceIndex <= length)
{
text += current.Substring(0, spaceIndex);
}
return text;
}
else
text += current;
}
break;
}
}
// Move to the next position
position = position.GetNextContextPosition(direction);
// Get the next context
if (position != null)
context = position.GetPointerContext(direction);
else
context = TextPointerContext.None;
}
return text;
}
现在你可以像这样获取光标所在的单词。
string before = GetWordByCaret(LogicalDirection.Backward);
string after = GetWordByCaret(LogicalDirection.Forward);
string word = before + after; // :)
- Prince Owen
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