如何在后面的c#代码中拆分句子并以新行显示

目的是分割字符串并在格式中显示换行符。
我已经尝试使用Environment.NewLine，但它不工作。

下面是我的代码:

stringArray = kidsCampDto.Message.Split(",".ToCharArray());
if (stringArray[0].Equals("successful."))
{
    lblSuccessMessage.ForeColor = System.Drawing.Color.Green;
    lblSuccessMessage.Text = string.Format("Registration & Payment Information:-" +Environment.NewLine
        + "Welcome to kids camp Programs, Successful Registered with Kids camp." + Environment.NewLine
        + "Athlet+e ID: {0} {1}." + Environment.NewLine
        + "Amount paid: ${2}." + Environment.NewLine
        + "Paid By: {3}." + Environment.NewLine
        + "Transaction Id: {4}." + Environment.NewLine
        + "Transaction Date:{5}." + Environment.NewLine
        + "Program: {6}",
        kidsCampDto.AthleteFirstName,
        kidsCampDto.AthleteLastName, stringArray[3], 
        kidsCampDto.CreditCardSelected == true ? "Credit card" : "Bank Account", stringArray[1],
        Convert.ToDateTime(stringArray[2]).ToShortDateString(),
        kidsCampDto.SeasonTrainingProgram.Equals("0") ? "4 weeks" : (kidsCampDto.SeasonTrainingProgram.Equals("1") ? "8 weeks" : "12 weeks"));
}