C＃System.OverflowException二进制到十进制和十六进制转换

Question

I am currently building ac# winform application to convert input from three textboxes, one decimal, one hex and one binary. So you would enter your decimal number in the decimal textbox and the equivalent hex and binary numbers would appear in their respective text boxes. Here is the code I used for the decimal and hex text boxes for the conversions.

  private void textBox1_TextChanged(object sender, EventArgs e)
    {
        //conversion to hex and binary for the other texbox's

        if (button20WasClicked == false) { 
           long x = Int64.Parse(textBox1.Text);
           textBox2.Text = Convert.ToString(x,16).ToUpper();

           long y = Int64.Parse(textBox1.Text);
           textBox3.Text = Convert.ToString(y,2);

       }
        else
        {

        }
        button20WasClicked = false;
    }


 private void textBox2_TextChanged(object sender, EventArgs e)
    {

        if (button20WasClicked == false)
        {
            long x = Int64.Parse(textBox2.Text, System.Globalization.NumberStyles.HexNumber);
            textBox1.Text = Convert.ToString(x, 10);

            long y = Int64.Parse(textBox2.Text, System.Globalization.NumberStyles.HexNumber);
            textBox3.Text = Convert.ToString(y, 2);

        }
        else
        {

        }
        button20WasClicked = false;
    }

Now these worked like a dream for converting decimal to hex and binary (textBox1) and hex to decimal and binary (textBox2) but when I try a similar approach on the textbox for inputing binary to convert to decimal and hex I keep getting an overflow exception was unhandled error, value was either too large or small for Int 64. I have tried changing to other size variables but get the same error. Everything I can find on the internet suggests I am on the right track with this .Convert approach but just can't get anything to work. Here is the code for the final text box causing the error.

  private void textBox3_TextChanged_1(object sender, EventArgs e)
    {
        if (button20WasClicked == false)
        {
            long x = Int64.Parse(textBox3.Text);
            textBox1.Text = Convert.ToString(x, 10);

            long y = Int64.Parse(textBox3.Text);
            textBox2.Text = Convert.ToString(y, 16);

        }
        else
        {

        }
        button20WasClicked = false;
    }

Any help appreciated as I have been working on this problem for two days now.

Answer 1

You should not use Parse methods.

When you convert long to string, you correctly use Convert.ToString overload that allows specifying a base

public static string ToString(long value, int toBase)

What you are missing is the corresponding reverse Convert.ToInt64 method

static long ToInt64(string value, int fromBase)

Shortly, change your parsing code in the three places respectively to

long x = Convert.ToInt64(textBox1.Text, 10);
long x = Convert.ToInt64(textBox2.Text, 16);
long x = Convert.ToInt64(textBox3.Text, 2);