richTextBox.Lines[0] = richTextBox.Lines[0]. Remove(0, 11)) this command does not work.

[vsfeedback]

This issue has been moved from a ticket on Developer Community.

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[severity:It's more difficult to complete my work]
richTextBox.Lines[0] = richTextBox.Lines[0]. Remove(0, 11)) this command does not work. It has no function. richTextBox.Lines[0] does not do its job. You have programmed it incompletely or programmed it incorrectly.

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Original Comments

Feedback Bot on 21/7/2025, 09:05 AM:

We have directed your feedback to the appropriate engineering team for further evaluation. The team will review the feedback and notify you about the next steps.

[miloush]

@harshit7962 WPF RTB does not have Lines property, this seems to be a WinForms issue.

[Amy-Li03]

Hi @harshit7962 , thanks for your ticket!

string.Remove(int startIndex, int count) method returns the new string after removing the specified part, instead of modifying the original string directly. So, richTextBox1.Lines[0].Remove(0, 2) doesn't actually modify the contents of richTextBox1.Lines[0], but returns a new string, you need to reassign to richTextBox1.Lines[0].

Please reference to following code:

 string[] line = richTextBox.Lines;
 line[0] = line[0].Remove(0, 11);
 richTextBox.Lines = line;

[harshit7962]

@vsfeedback does the above changes solve the issue?