C# Calling a String name by another concatenated string and variable

Question

I've been searching for this a lot, but I haven't found anything close to what I need, and maybe it's something simple, but the things that I get are only how to concatenate strings using "+" or the Format procedure.

What I would like to know is how to call a string that contains the HEX format of a color by changing another string.

Heres and example:

I have named the following strings:

string Color_Option1 = "#FF17868B";
string Color_Option2 = "#FFFFFFFF";
string Color_Option3 = "#FF000000";

And this variable:

private static string m_optionclicked = "";
        public static string OptionClicked
        {
            get { return m_optionclicked; }
            set { m_optionclicked = value; }
        }

Then I have 3 buttons and one TextBlock, and when a button is clicked they put a value on "OptionClicked", ex:

OptionClicked = "Option2";

So depending on which button is clicked I want to change the background color of the TextBlock like this:

TextBlock.Background = (SolidColorBrush)(new BrushConverter().ConvertFrom("Color_" + OptionClicked));

But I get and error everytime on the background line, does anyone knows how can I call the string called "Color_Option2" with a similar syntaxis?

I've made sure that OptionClicked has the value "Option2" and it actually works if I write "Color_Option2" instead of concatenating the string and variable.

BTW, this is a simplified example, I have a lot of buttons, textblocks, and colors, so making a chain of "If"s or determining one by one would make my life miserable.

Thanks in advance.

Seems like you might want to consider storing this information in a dictionary to allow for easy retrieval based on the option name. Also, you might want to consider including the error if you want any sort of real answer. — David L, Jun 27 '16 at 19:45
Sorry, the error that pops up is "FormatException was unhandled - An unhandled exception of type 'System.FormatException' occurred in PresentationCore.dll" But I supposed that it was because I was calling the string in a wrong way. And I'm new to C# but what I searched about storing information in a dictionary seems to be sort of the same as how I'm storing my information, but the problem would still be on how to call it. I might be wrong so if I am, please tell me, I still want to learn a lot more of C# — Jorge, Jun 27 '16 at 20:28

score 0 · Accepted Answer · answered Jun 27 '16 at 19:54

0

If you want to do this through reflection, you could have a class with public fields, such as

class ColorClass
{
    public string Color_Option1 = "#FF17868B";
    public string Color_Option2 = "#FFFFFFFF";
    public string Color_Option3 = "#FF000000";
}

and then to grab the values,

ColorClass colorClass = new ColorClass();
(string)typeof(ColorClass).GetField("Color_" + OptionClicked).GetValue(colorClass);

The other way of solving this is as David L said in comments, just create a dictionary with the key as your string variable name.

answered Jun 27 '16 at 19:54

Dispersia

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This certainly works, although it is a shame to incur reflection overhead for this. – David L Jun 27 '16 at 20:16
Thanks a lot, it worked, just in case someone else wants to try it, this is how i did it. ColorClass colorClass = new ColorClass(); / TextBlock.Background = (SolidColorBrush)(new BrushConverter().ConvertFrom((string)typeof(ColorClass).GetField("Color_" + OptionClicked).GetValue(colorClass))); Although it seems like a lot of work for just this, in VB its way easier. – Jorge Jun 27 '16 at 20:29

C# Calling a String name by another concatenated string and variable

1 Answers1