CODEWITHSUNDEEP
c#winformsclickrichtextbox
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Reputation: 446

Get caret position in RichTextBox_Click event

I'm working on a text editor which includes a RichTextBox. One of the features that I want to implement is to show in a TextBox the current Line and Column of the caret of the forementioned RichTextBox at any moment.

Here's part of the code that I use (the rest of my code has nothing to do with my issue):

int selectionStart = richTextBox.SelectionStart;
int lineFromCharIndex = richTextBox.GetLineFromCharIndex(selectionStart);
int charIndexFromLine = richTextBox.GetFirstCharIndexFromLine(lineFromCharIndex);

currentLine = richTextBox.GetLineFromCharIndex(selectionStart) + 1;
currentCol = richTextBox.SelectionStart - charIndexFromLine + 1;

At this point, I should mention that when someone is using a RichTextBox, there are three ways that the caret can change location:

The code that I posted above works with no issues in the first two cases. However, it doesn't really work in the third case.

I tried using the Click event and I noticed that the selectionStart variable would always get the value of 0, which means that I always get the same and wrong results. Moreover, using the same code on other events like MouseClick and MouseUp did not solve my problem since selectionStart is 0 even in the duration of these events.

So, how can I get the current Line and column everytime the user clicks on the RichTextBox?

Upvotes: 1

Views: 925

Answers (2)

toddmo
toddmo

Reputation: 22406

You want something like:

private void richTextBox1_MouseUp(object sender, MouseEventArgs e)
{
        RichTextBox box = (RichTextBox)sender;
        Point mouseLocation = new Point(e.X, e.Y);
        box.SelectionStart = box.GetCharIndexFromPosition(mouseLocation);
        box.SelectionLength = 0;
        int selectionStart = richTextBox.SelectionStart;
        int lineFromCharIndex = box.GetLineFromCharIndex(selectionStart);
        int charIndexFromLine = box.GetFirstCharIndexFromLine(lineFromCharIndex);

        currentLine = box.GetLineFromCharIndex(selectionStart) + 1;
        currentCol = box.SelectionStart - charIndexFromLine + 1;
}

Upvotes: 1

Peter Duniho
Peter Duniho

Reputation: 70652

It seems to me that what you really want is to handle the TextBoxBase.SelectionChanged event. Then any action that causes the selection to change will invoke your code, and as an added benefit the current selection will have been updated by the time your event handler is called, and you'll be assured of getting correct values.

If that does not address your specific need, then I must not be understanding the question. In that case, please provide a good, minimal, complete code example that shows clearly what you're trying to do, with a precise description of what that code does and how that's different from what you want it to do.

Upvotes: 1

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