Method to decode a JWT and pretty print the JSON contents

JwtCracker.cs

//Assume the input is in a control called txtJwtIn,
//and the output will be placed in a control called txtJwtOut
var jwtHandler = new JwtSecurityTokenHandler();
var jwtInput = txtJwtIn.Text;

//Check if readable token (string is in a JWT format)
var readableToken = jwtHandler.CanReadToken(jwtInput);

if(readableToken != true)
{
  txtJwtOut.Text = "The token doesn't seem to be in a proper JWT format.";
}
if(readableToken == true)
{
  var token = jwtHandler.ReadJwtToken(jwtInput);
    
  //Extract the headers of the JWT
  var headers = token.Header;
  var jwtHeader = "{";
  foreach(var h in headers)
  {
    jwtHeader += '"' + h.Key + "\":\"" + h.Value + "\",";
  }
  jwtHeader += "}";
  txtJwtOut.Text = "Header:\r\n" + JToken.Parse(jwtHeader).ToString(Formatting.Indented);

  //Extract the payload of the JWT
  var claims = token.Claims;
  var jwtPayload = "{";
  foreach(Claim c in claims)
  {
    jwtPayload += '"' + c.Type + "\":\"" + c.Value + "\",";
  }
  jwtPayload += "}";
  txtJwtOut.Text += "\r\nPayload:\r\n" + JToken.Parse(jwtPayload).ToString(Formatting.Indented);  
}