Function to see if Hex color is valid?

  • Thread starter Thread starter Mark B
  • Start date Start date
M

Mark B

I'd like a function to inspect a string to see if it is a valid Hexadecimal
color:

fIsValidHexColor(strHex) as Boolean

Anyone come across this before?
 
Mark B said:
I'd like a function to inspect a string to see if it is a valid
Hexadecimal color:

fIsValidHexColor(strHex) as Boolean

Anyone come across this before?
Click to expand...


Doesn't it just need to be true that the string can be parsed to an int? If
so, this works:

bool TestString(string s)
{
int argb;
if (int.TryParse(s, System.Globalization.NumberStyles.HexNumber, null, out
argb))
return true;
else return false;
}
 
I'd like a function to inspect a string to see if it is a valid Hexadecimal
color:

fIsValidHexColor(strHex) as Boolean

Anyone come across this before?
Click to expand...

The answer depends on what format the string is in.

If it is just the hex digits, then you can try to parse as a
hexadecimal number into an Integer and make sure the result is >= 0
and <= &HFFFFFF.

If the string will have some sort of hex identifier (leading &H,
leading 0x, etc.) you will also need to check for that.

Also, you might or might not want to force the string to have at least
5 hex digits or maybe even require 6.
 
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