how to insert qoutation marks into string csharp

                
                        Insert the escape sequence \" 
   textBox1.Text = "She said, \"You deserve a treat!\" "; 

Insert the ASCII or Unicode character 
   textBox1.Text = "She said, " + '\u0022' + "You deserve a treat!" + '\u0022'; 


Define a constant for the character
	const string quote = "\"";  
	textBox1.Text = "She said, " + quote +  "You deserve a treat!"+ quote ;