Uppercase checker C# VS

[C_Oleyers]

Is their a program in which it will determine if a letter in a textbox is uppercase?
This program is for Password checker as it will only be granted if the first letter is uppercase.

     char[]
     v = Password.Text.ToCharArray();
//i want to check the first letter if its uppercase
     char s = v[0];
//event
     if (s ___ )
     {
         pictureboxD.Visible = false;
     }

[pritaeas]

I suggest to use Regex.Match(), because it can determine if the first character is an uppercase letter easily with ^[A-Z].*

https://docs.microsoft.com/en-us/dotnet/api/system.text.regularexpressions.regex.match?view=netcore-3.1#System_Text_RegularExpressions_Regex_Match_System_String_