无法确定条件表达式的类型，因为“int”和“string”之间没有隐式转换

Question

pls any one here can help me fix this

checked
{
    foreach (string text2 in ParametersString)
    {
        int num = Conversions.ToInteger((!Versioned.IsNumeric(text2)) ? -1 : text2);
        if (num == -1)
        {
            Interaction.MsgBox(string.Format("Entering characters is not allowed ---> {0}", text2), MsgBoxStyle.Critical, Class10.string_4);
        }
        else if (!this.method_2(num))
        {
            Interaction.MsgBox(string.Format("The specified port ({0}) is already in use", text2), MsgBoxStyle.Critical, Class10.string_4);
            Environment.Exit(0);
        }
        else
        {
            this.Listener = new TcpListener(IPAddress.Any, num);
            this.Listener.Server.SendTimeout = -1;
            this.Listener.Server.ReceiveTimeout = -1;
            this.Listener.Server.SendBufferSize = 999999;
            this.Listener.Server.ReceiveBufferSize = 999999;
            this.Listener.Start();
            int num2 = 5;
            string string_ = Class7.string_0;
            if (Operators.CompareString(string_, "High", false) != 0)
            {
                if (Operators.CompareString(string_, "Normal", false) == 0)
                {
                    num2 = 10;
                }
                else if (Operators.CompareString(string_, "Low", false) == 0)
                {
                    num2 = 5;
                }
            }
            else
            {
                num2 = 16;
            }
            int num3 = num2;
            for (int j = 1; j <= num3; j++)
            {
                new Thread(new ThreadStart(this.ScanerAsync)).Start();
            }
            int num4 = num2;
            for (int k = 1; k <= num4; k++)
            {
                new Thread(new ThreadStart(this.method_1)).Start();
            }
            text += Conversions.ToString(num);
            this.closing = false;
        }
    }
    Class6.string_0 = text;
}

Error in line

int num = Conversions.ToInteger((!Versioned.IsNumeric(text2)) ? -1 : text2);

Error :

Type of conditional expression cannot be determined because there is no implicit conversion between 'int' and 'string'

Answer 1

Type of conditional expression cannot be determined because there is no implicit conversion between 'int' and 'string'

This means that return type of !Versioned.IsNumeric(text2)) ? -1 : text2 !Versioned.IsNumeric(text2)) ? -1 : text2 can't be narrowed to single type. It is either int ( -1 ) or string ( text2 ).

Treat both as string

int num = Conversions.ToInteger((!Versioned.IsNumeric(text2)) ? "-1" : text2);

Now, in either case the result of the conditional tenary operator will be string

Apply the condition outside

int num = Versioned.IsNumeric(text2) ? Conversions.ToInteger(text2) : -1;

• If text2 is numeric then convert string to int
• If text2 is not numeric then use -1