C# – Get int value from enum

The simplest way to get an enum’s int value is by casting it to an int. Here’s an example: This outputs the following: When the enum is generic (of type ‘Enum’) You can’t cast a generic ‘Enum’ to int, otherwise you get a compiler error (CS0030 Cannot convert type ‘System.Enum’ to ‘int’). Use Convert.Int32() instead. … Read more

C# – Convert a string to an int

There are three ways to convert a string to an int: I’ll show examples of using these approaches. Use int.Parse() int.Parse() takes a string and converts it to a 32-bit integer. Here’s an example of using int.Parse(): When conversion fails int.Parse() throws an exception if it can’t convert the string to an int. There are … Read more

C# – How to convert char to int

Converting a char to an int means getting the numeric value that the char represents (i.e. ‘1’ to 1). This is not the same as casting the char to an int, which gives you the char’s underlying value (i.e. ‘1’ is 49). There are three ways to convert a char to an int: I’ll show … Read more

OverflowException: Value was either too large or too small for an int32

Problem When you try to convert a string to an integer with int.Parse() (or Convert.ToInt32()), you get the following exception: System.OverflowException: Value was either too large or too small for an Int32. The problem is the integer value in the string can’t fit in the 32-bit integer. Int32 (int) can only hold values between -2147483648 … Read more

C# – Parse a comma-separated string into a list of integers

Let’s say you want to parse a comma-separated string into a list of integers. For example, you have “1,2,3” and you want to parse it into [1,2,3]. This is different from parsing CSV with rows of comma-separated values. This is more straightforward. You can use string.Split(“,”) to get the individual string values and then convert … Read more

Error: Attribute constructor has an invalid parameter type

Problem When you try to pass in an attribute constructor parameter to a custom attribute, you get one of the following compiler errors: Error CS0181 Attribute constructor parameter has type ‘Color’ which is not a valid attribute parameter type Error CS0655 ‘Color’ is not a valid named attribute argument because it is not a valid … Read more

C# – Parse a comma-separated string from app.config

I’ll show how to parse comma-separated integer values from app.config and load them into a HashSet for efficient lookups. First, take a look at the setting (retryStatusCodes) in app.config: To load and parse this setting from app.config, do the following: The following code shows how to do this: Note: You have to add a reference … Read more