The format of the input string is incorrect.

Valerie Meunier

i received from someone of your experts this code in order to accept both integer and double in the same textbox.

The problem is that when entering a double (5,2), i get an error "The format of the input string is incorrect." at line int valueInt = Int32.Parse(textboxValue);. The inversre is ok: when entering a integer, there is no error.

How to avoid this?

Thanks

private void textBox1_KeyPress(object sender, KeyPressEventArgs e)
{
    // Verify that the pressed key isn't CTRL or any non-numeric digit 
    if (!char.IsControl(e.KeyChar) && !char.IsDigit(e.KeyChar) && (e.KeyChar != ','))
    {
        e.Handled = true;
    }

    // If you want, you can allow decimal (float) numbers 
    if (e.KeyChar == ',' && (sender as TextBox).Text.IndexOf(',') > -1)
    {
        e.Handled = true;
    }
}

private void button1_Click(object sender, EventArgs e)
{
    string textboxValue = textBox1.Text;
    // Retrieve as decimal 
    decimal valueDec = decimal.Parse(textboxValue);
    label1.Text = valueDec.ToString();

    // Retrieve as integer 
    int valueInt = Int32.Parse(textboxValue);// error
    label2.Text = valueInt.ToString();
}

9 Replies

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Sachin Singh4y ago
haha, great. have you tried by interchanging them?
now it should work.
decimal d;
int x;
if (int32.TryParse(textBox1.Text, out x))
{
label1.Text = x.ToString();
}
else
{
decimal.TryParse(textBox1.Text, out d);
label2.Text = d.ToString();
}
Valerie Meunier4y ago
Hi Sachin

I have added int x and jave replaced 'd' with 'x' in the line Int32.TryParse(textBox1.Text, out x); because of the error : cannot convert out decimal to out int.

decimal d;
int x;
if (decimal.TryParse(textBox1.Text, out d))
{
label1.Text = d.ToString();
}
else
{
Int32.TryParse(textBox1.Text, out x);
label2.Text = x.ToString();
}

But now, when i type 5 or 5.5, only label1 is filled, never label2 (exept when entering nothing, then is label2=0).
It seems dat everything is considered as decimal.
Sachin Singh4y ago
Ohh, Yes, ofcourse for decimal int won't work. i forgot to mention the if else condition.
To resolve this
decimal d;
if(decimal.TryParse(textBox1.Text, out d))
{
   label1.Text=d.ToString();
}
else
{
  int32.TryParse(textBox1.Text, out d)
label2.Text=d.ToString();
}
Valerie Meunier4y ago
Hi guys,
I changed the decimal delimiter to a dot. I tried in Console Application with ReadLine and it works. But i still have the same error (The format of the input string is incorrect) at the line int valueInt = Int32.Parse(textboxValue) when entering 5.5 . As already said, when entering 5, no error. The error occurs never at the line decimal valueDec = decimal.Parse(textboxValue).

Did you really test this? Why should o get an error and not you? Very strange.
Thanks
This is the code:
private void button1_Click(object sender, EventArgs e)
{
string textboxValue = textBox1.Text;
decimal valueDec = decimal.Parse(textboxValue);
label1.Text = valueDec.ToString();
int valueInt = Int32.Parse(textboxValue); //error here
label2.Text = valueInt.ToString();
}
private void textBox1_KeyPress(object sender, KeyPressEventArgs e)
{
if (!char.IsControl(e.KeyChar) && !char.IsDigit(e.KeyChar) && (e.KeyChar != '.'))
{ e.Handled = true; }
if (e.KeyChar == '.' && (sender as TextBox).Text.IndexOf('.') > -1)
{ e.Handled = true; }
}
Sachin Singh4y ago
Is it necessary for you? can't you set your PC to consider (dot) as dot and not comma(,) ??
here how you can do it.

Settings/time&language/under related settings click “Additional date, time, & regional settings”/under region click “change date, time, or number formats/a dialog box pops up, click additional settings/numbers tab, decimal symbol - change to .
Apply, ok,
then apply, ok
Valerie Meunier4y ago
The comma is because of my country setting and Windows language (Dutch). The comma is the decimal delimiter for me. Also in Console Application, i have to enter e.g. '5,2' as double in Console.ReadLine(). '5.2' is considered as text. When programming, then i have to type '5.2' in the code.
Muhammad Imran Ansari4y ago
First remove comma (5,2) from your value and you can also use Math.Truncate() method to get only integral part of any fractional digits.

int valueInt = (int)Math.Truncate(Convert.ToDecimal(textboxValue));
Sachin Singh4y ago
I don't know why are you using comma (,) instead of dot (.), my code was
private void textBox1_KeyPress(object sender, KeyPressEventArgs e)
{
    // Verify that the pressed key isn't CTRL or any non-numeric digit
    if (!char.IsControl(e.KeyChar) && !char.IsDigit(e.KeyChar) && (e.KeyChar != '.'))
    {
        e.Handled = true;
    }

    // If you want, you can allow decimal (float) numbers
    if ((e.KeyChar == '.') && ((sender as TextBox).Text.IndexOf('.') > -1))
    {
        e.Handled = true;
    }
}

string textboxValue = textBox1.Text;

// Retrieve as decimal
decimal valueDec = decimal.Parse(textboxValue);

// Retrieve as integer
int valueInt = Int32.Parse(textboxValue);
which works fine.
Please tell me the reason of using comma.
Amit Mohanty4y ago
Hey did you check you are getting correct value when you convert textbox value to decimal. Please check once again, i think you are not getting the right value.

Please check with below code. May be this what you want.
private void textBox1_KeyPress(object sender, KeyPressEventArgs e)
{
    // allow only numbers
    if (e.KeyChar >= 48 && e.KeyChar <= 57 || e.KeyChar == 46 || e.KeyChar == 45)
    {
        e.Handled = false;
    }
    else
    {
        e.Handled = true;
    }

    // only allow one decimal point
    if (e.KeyChar == 46 && (sender as TextBox).Text.IndexOf('.') > -1)
    {
        e.Handled = true;
    }

    // allow backspace
    if (e.KeyChar == 8)
    {
        e.Handled = false;
    }
}

private void button1_Click(object sender, System.EventArgs e)
{
    string textboxValue = textBox1.Text;
    // Retrieve as decimal
    decimal valueDec = decimal.Parse(textboxValue);
    label1.Text = valueDec.ToString();

    // Retrieve as integer
    int valueInt = (int)decimal.Parse(textboxValue);// error
    label2.Text = valueInt.ToString();
}
Now when you enter decimal value as 5.2 (not as 5,2) it will convert it to decimal value.