How to convert image to binary and get result in text box

I need to convert image to binary and get result in text box .

i using the following function :

Image found in path D:/person.jpg

public static byte[] ImageToBinary(string _path)  
{  
FileStream fS = new FileStream(_path, FileMode.Open, FileAccess.Read);  
byte[] b = new byte[fS.Length];  
fS.Read(b, 0, (int)fS.Length);  
fS.Close();  
return b;  
}  

How to receive the value returned from function ImageToBinary in textbox1 ?

I work in c# windows form c#