unity - string.tryparse c#




How can I convert String to Int? (19)

I have a TextBoxD1.Text and I want to convert it to an int to store it in a database.

How can I do this?


You can write your own extesion method

public static class IntegerExtensions
{
    public static int ParseInt(this string value, int defaultValue = 0)
    {
        int parsedValue;
        if (int.TryParse(value, out parsedValue))
        {
            return parsedValue;
        }

        return defaultValue;
    }

    public static int? ParseNullableInt(this string value)
    {
        if (string.IsNullOrEmpty(value))
        {
            return null;
        }

        return value.ParseInt();
    }
}

And wherever in code just call

int myNumber = someString.ParseInt(); // returns value or 0
int age = someString.ParseInt(18); // with default value 18
int? userId = someString.ParseNullableInt(); // returns value or null

In this concrete case

int yourValue = TextBoxD1.Text.ParseInt();

As explained in the TryParse documentation, TryParse() returns a boolean which indicates that a valid number was found:

bool success = Int32.TryParse(TextBoxD1.Text, out val);

if (success)
{
// put val in database
}
else
{
// handle the case that the string doesn't contain a valid number
}

Conversion of string to int can be done for: int, Int32, Int64 and other data types reflecting integer data types in .NET

Below example shows this conversion:

This show (for info) data adapter element initialized to int value. The same can be done directly like,

int xxiiqVal = Int32.Parse(strNabcd);

Ex.

string strNii = "";
UsrDataAdapter.SelectCommand.Parameters["@Nii"].Value = Int32.Parse(strNii );

Link to see this demo.


Enjoy it...

int i = 0;
string s = "123";
i =int.Parse(s);
i = Convert.ToInt32(s);

METHOD 1

int  TheAnswer1 = 0;
bool Success = Int32.TryParse("42", out TheAnswer1);
if (!Success) {
    Console.WriteLine("String not Convertable to an Integer");
}

METHOD 2

int TheAnswer2 = 0;
try {
    TheAnswer2 = Int32.Parse("42");
}
catch {
    Console.WriteLine("String not Convertable to an Integer");
}

METHOD 3

int TheAnswer3 = 0;
try {
    TheAnswer3 = Int32.Parse("42");
}
catch (FormatException) {
    Console.WriteLine("String not in the correct format for an Integer");
}
catch (ArgumentNullException) {
    Console.WriteLine("String is null");
}
catch (OverflowException) {
    Console.WriteLine("String represents a number less than"
                      + "MinValue or greater than MaxValue");
}

The most simple way is to use an extension helper like this:

public static class StrExtensions
{
  public static int ToInt(this string s, int defVal = 0) => int.TryParse(s, out var v) ? v : defVal;
  public static int? ToNullableInt(this string s, int? defVal = null) => int.TryParse(s, out var v) ? v : defVal;
}

Usage is so simple:

var x = "123".ToInt(); // 123
var y = "abc".ToInt(); // 0

string t = null;
var z = t.ToInt(-1); // -1
var w = "abc".ToNullableInt(); // null


Try this:

int x = Int32.Parse(TextBoxD1.Text);

or better yet:

int x = 0;

Int32.TryParse(TextBoxD1.Text, out x);

Also, since Int32.TryParse returns a bool you can use its return value to make decisions about the results of the parsing attempt:

int x = 0;

if (Int32.TryParse(TextBoxD1.Text, out x))
{
    // you know that the parsing attempt
    // was successful
}

If you are curious, the difference between Parse and TryParse is best summed up like this:

The TryParse method is like the Parse method, except the TryParse method does not throw an exception if the conversion fails. It eliminates the need to use exception handling to test for a FormatException in the event that s is invalid and cannot be successfully parsed. - MSDN


You also may use an extension method, so it will be more readable (although everybody is already used to the regular Parse functions).

public static class StringExtensions
{
    /// <summary>
    /// Converts a string to int.
    /// </summary>
    /// <param name="value">The string to convert.</param>
    /// <returns>The converted integer.</returns>
    public static int ParseToInt32(this string value)
    {
        return int.Parse(value);
    }

    /// <summary>
    /// Checks whether the value is integer.
    /// </summary>
    /// <param name="value">The string to check.</param>
    /// <param name="result">The out int parameter.</param>
    /// <returns>true if the value is an integer; otherwise, false.</returns>
    public static bool TryParseToInt32(this string value, out int result)
    {
        return int.TryParse(value, out result);
    }
}

And then you can call it that way:

  1. If you are sure that your string is an integer, like "50".

    int num = TextBoxD1.Text.ParseToInt32();
    
  2. If you are not sure and want to prevent crashes.

    int num;
    if (TextBoxD1.Text.TryParseToInt32(out num))
    {
        //The parse was successful, the num has the parsed value.
    }
    

To make it more dynamic, so you can parse it also to double, float, etc., you can make a generic extension.


You can convert a string to int in C# using:

Functions of convert class i.e. Convert.ToInt16(), Convert.ToInt32(), Convert.ToInt64() or by using Parse and TryParse Functions. Examples are given here.


You can try this, it will work:

int x = Convert.ToInt32(TextBoxD1.Text);

The string value in the variable TextBoxD1.Text will be converted into Int32 and will be stored in x.


You can use either,

int i = Convert.ToInt32(TextBoxD1.Text);

or

int i =int.Parse(TextBoxD1.Text);

the way i always do this is like this

using System;
using System.Collections.Generic;
using System.ComponentModel;
using System.Data;
using System.Drawing;
using System.Linq;
using System.Text;
using System.Windows.Forms;

namespace example_string_to_int
{
    public partial class Form1 : Form
    {
        public Form1()
        {
            InitializeComponent();
        }

        private void button1_Click(object sender, EventArgs e)
        {
            string a = textBox1.Text;
            // this turns the text in text box 1 into a string
            int b;
            if (!int.TryParse(a, out b))
            {
                MessageBox.Show("this is not a number");
            }
            else
            {
                textBox2.Text = a+" is a number" ;
            }
            // then this if statment says if the string not a number display an error elce now you will have an intager.
        }
    }
}

this is how i would do it, i hope this helps. (:


this may help you ;D

{
    public partial class Form1 : Form
    {
        public Form1()
        {
            InitializeComponent();
        }

        float Stukprijs;
        float Aantal;
        private void label2_Click(object sender, EventArgs e)
        {

        }

        private void button2_Click(object sender, EventArgs e)
        {
            MessageBox.Show("In de eersre textbox staat een geldbedrag." + Environment.NewLine + "In de tweede textbox staat een aantal." + Environment.NewLine + "Bereken wat er moetworden betaald." + Environment.NewLine + "Je krijgt 15% korting over het bedrag BOVEN de 100." + Environment.NewLine + "Als de korting meer dan 10 euri is," + Environment.NewLine + "wordt de korting textbox lichtgroen");
        }

        private void button1_Click(object sender, EventArgs e)
        {
            errorProvider1.Clear();
            errorProvider2.Clear();
            if (float.TryParse(textBox1.Text, out Stukprijs))
            {
                if (float.TryParse(textBox2.Text, out Aantal))
                {
                    float Totaal = Stukprijs * Aantal;
                    string Output = Totaal.ToString();
                    textBox3.Text = Output;
                    if (Totaal >= 100)
                    {
                        float korting = Totaal - 100;
                        float korting2 = korting / 100 * 15;
                        string Output2 = korting2.ToString();
                        textBox4.Text = Output2;
                        if (korting2 >= 10)
                        {
                            textBox4.BackColor = Color.LightGreen;
                        }
                        else
                        {
                            textBox4.BackColor = SystemColors.Control;
                        }
                    }
                    else
                    {
                        textBox4.Text = "0";
                        textBox4.BackColor = SystemColors.Control;
                    }
                }
                else
                {
                    errorProvider2.SetError(textBox2, "Aantal plz!");
                }

            }
            else
            {
                errorProvider1.SetError(textBox1, "Bedrag plz!");
                if (float.TryParse(textBox2.Text, out Aantal))
                {

                }
                else
                {
                    errorProvider2.SetError(textBox2, "Aantal plz!");
                }
            }

        }

        private void BTNwissel_Click(object sender, EventArgs e)
        {
            //LL, LU, LR, LD.
            Color c = LL.BackColor;
            LL.BackColor = LU.BackColor;
            LU.BackColor = LR.BackColor;
            LR.BackColor = LD.BackColor;
            LD.BackColor = c;
        }

        private void button3_Click(object sender, EventArgs e)
        {
            MessageBox.Show("zorg dat de kleuren linksom wisselen als je op de knop drukt.");
        }
    }
}

//May be quite some time ago but I just want throw in some line for any one who may still need it

int intValue;
string strValue = "2021";

try
{
    intValue = Convert.ToInt32(strValue);
}
catch
{
    //Default Value if conversion fails OR return specified error
    // Example 
    intValue = 2000;
}

Convert.ToInt32( TextBoxD1.Text );

Use this if you feel confident that the contents of the text box is a valid int. A safer option is

int val = 0;
Int32.TryParse( TextBoxD1.Text, out val );

This will provide you with some default value you can use. Int32.TryParse also returns a boolean value indicating whether it was able to parse or not, so you can even use it as the condition of an if statement.

if( Int32.TryParse( TextBoxD1.Text, out val ){
  DoSomething(..);
} else {
  HandleBadInput(..);
}

int myInt = int.Parse(TextBoxD1.Text)

Another way would be:

bool isConvertible = false;
int myInt = 0;

isConvertible = int.TryParse(TextBoxD1.Text, out myInt);

The difference between the two is that the first one would throw an exception if the value in your textbox can't be converted, whereas the second one would just return false.


int x = 0;
int.TryParse(TextBoxD1.Text, out x);

The TryParse statement returns a boolean representing whether the parse has succeeded or not. If it succeeded, the parsed value is stored into the second parameter.

See Int32.TryParse Method (String, Int32) for more detailed information.


int.TryParse()

It won't throw if the text is not numeric.





type-conversion