remove all characters in string c# code example

Example 1: remove all text after string c#

string input = "text?here";
int index = input.LastIndexOf("?"); // Character to remove "?"
if (index > 0)
    input = input.Substring(0, index); // This will remove all text after character ?

Example 2: remove control characters from string c#

string input; // this is your input string
string output = new string(input.Where(c => !char.IsControl(c)).ToArray());