Coversion from string ""to double type is invalid

Rams

Hi All,

iam passing a textbox value(the value is 10:1:1) into a string and when iam running the application iam getting the following error "coversion from string "10:1:1" to double type is invalid". kindly find the code below and help me on the same: (also the textbox values should be greater than 0 always)

Dim strEncrypt As String = txtData.Text

If strEncrypt > 0 Then// iam getting the error here txtEncryptedData.Text = Encrypt(strEncrypt)

Else MessageBox.Show(

"Enter the Value greater then 0:")End If

Thanks,
Rams

8 Replies

Know the answer? Post it — somebody with the same question will find it here.

Vulpes15y ago
Accepted answer
Incidentally, you won't be able to convert a string such as "10:1:1" directly to a double as it's really 3 numbers separated by colons.

You could split the string first and then convert each element to a double:

Dim elements As String() = strEncrypt.Split(":"c)
Dim d As Double = Double.Parse(elements(0))
MessageBox.Show(d.ToString()) ' 10
Rams15y ago
Here is the solution that worked for me : Function Check(ByVal strEncrypt As String) As Boolean Dim parts As String() parts = strEncrypt.Split(":") If parts.Length = 0 Then Check = False Else Check = True For Each sval As String In parts Check = Check And Int32.Parse(sval) > 0 Next End If End Function
Mamta M15y ago
Great to hear that. Rams can you post the final solution so that it may help other members too?
Rams15y ago
Thank you all, i got it solved. Thanks a lot vulpes it worked for me
Prabhu Raja15y ago
Hi,

i agree with vulpes, its good one. Also try this one.

Dim elements As String() = strEncrypt.Split(":"c);

Dim firstnumber As Double;

// Try to use TryParse(), you handle Conversion Errors effectively. Your Application will not be disturbed by these kind of errors.
bool isConverted = Double.TryParse(elements(0).ToString(), out firstnumber) ;

if ( isConverted == true)
// Value Converted Successfully
Else
// Value Conversion failed.

MessageBox.Show(d.ToString()); ' 10
Javeed M Shaikh15y ago
Hi Rams,

If you want to check that the textbox value does not start with "0" than use the following:

if (!TextBox1.Text.Trim().StartsWith("0"))
{
// do your stuff here
}

Also I am not sure if you can convert value "10:1:1" to double.

Please do not forget to mark "Accepted Answer".
Rams15y ago
Hi Mamta,

I tried with
If(
i want to check that the textbox value does not start with 0
Convert.ToDouble(strEncrypt) > 0) but iam getting the error as "Input string was not in a correct format."
Mamta M15y ago
How are you doing this: if (strEncrypt > 0) when actually strEncrypt is a string??

Instead, you should write:

if (Convert.ToDouble(strEncrypt) > 0)