Question

I am passing a hex value in my QueryString. I’d like to convert that to a color to use the ForeColor in a cell in a grid view. Tried both System.Drawing.ColorTranslator.FromHtml() and System.Drawing.Color.FromArgb() with no luck.

My QueryString is urlencoded so the part that matters looks like:

QueryString...&color=%23AA4643

Below is how I have tried .FromArg:

string sColor = Request.QueryString["color"]; // sColor is now #AA4643
Int32 iColorInt = Convert.ToInt32(sColor,16); //Get error message - Could not find any recognizable digits
Color curveColor = System.Drawing.Color.FromArgb(iColorInt); //Never makes it here

And here is how I have tried .FromHtml:

string sColor = Request.QueryString["color"]; 
System.Drawing.Color myColor = new System.Drawing.Color();
myColor = System.Drawing.ColorTranslator.FromHtml(sColor);

In this case myColor gets set to – myColor = “{Name=ffaa4643, ARGB=(255, 170, 70, 67)}”

But when I go to use it I get an error:

Index was out of range. Must be non-negative and less than the size of the collection.
Parameter name: index

Any and all help greatly appreciated

Answer 1

Try this:

string sColor = Request.QueryString["color"]; // sColor is now #AA4643
Int32 iColorInt = Convert.ToInt32(sColor.Substring(1),16); 
Color curveColor = System.Drawing.Color.FromArgb(iColorInt);