snippetcsharpCritical
Convert a string to an enum in C#
Viewed 0 times
stringconvertenum
Problem
What's the best way to convert a string to an enumeration value in C#?
I have an HTML select tag containing the values of an enumeration. When the page is posted, I want to pick up the value (which will be in the form of a string) and convert it to the corresponding enumeration value.
In an ideal world, I could do something like this:
but that isn't valid code.
I have an HTML select tag containing the values of an enumeration. When the page is posted, I want to pick up the value (which will be in the form of a string) and convert it to the corresponding enumeration value.
In an ideal world, I could do something like this:
StatusEnum MyStatus = StatusEnum.Parse("Active");but that isn't valid code.
Solution
In .NET Core and .NET Framework ≥4.0 there is a generic parse method:
This also includes C#7's new inline
If you have access to C#7 and the latest .NET this is the best way.
Original Answer
In .NET it's rather ugly (until 4 or above):
I tend to simplify this with:
Then I can do:
One option suggested in the comments is to add an extension, which is simple enough:
Finally, you may want to have a default enum to use if the string cannot be parsed:
Which makes this the call:
However, I would be careful adding an extension method like this to
Enum.TryParse("Active", out StatusEnum myStatus);This also includes C#7's new inline
out variables, so this does the try-parse, conversion to the explicit enum type and initialises+populates the myStatus variable.If you have access to C#7 and the latest .NET this is the best way.
Original Answer
In .NET it's rather ugly (until 4 or above):
StatusEnum MyStatus = (StatusEnum) Enum.Parse(typeof(StatusEnum), "Active", true);I tend to simplify this with:
public static T ParseEnum(string value)
{
return (T) Enum.Parse(typeof(T), value, true);
}Then I can do:
StatusEnum MyStatus = EnumUtil.ParseEnum("Active");One option suggested in the comments is to add an extension, which is simple enough:
public static T ToEnum(this string value)
{
return (T) Enum.Parse(typeof(T), value, true);
}
StatusEnum MyStatus = "Active".ToEnum();Finally, you may want to have a default enum to use if the string cannot be parsed:
public static T ToEnum(this string value, T defaultValue)
{
if (string.IsNullOrEmpty(value))
{
return defaultValue;
}
T result;
return Enum.TryParse(value, true, out result) ? result : defaultValue;
}Which makes this the call:
StatusEnum MyStatus = "Active".ToEnum(StatusEnum.None);However, I would be careful adding an extension method like this to
string as (without namespace control) it will appear on all instances of string whether they hold an enum or not (so 1234.ToString().ToEnum(StatusEnum.None) would be valid but nonsensical) . It's often be best to avoid cluttering Microsoft's core classes with extra methods that only apply in very specific contexts unless your entire development team has a very good understanding of what those extensions do.Code Snippets
Enum.TryParse("Active", out StatusEnum myStatus);StatusEnum MyStatus = (StatusEnum) Enum.Parse(typeof(StatusEnum), "Active", true);public static T ParseEnum<T>(string value)
{
return (T) Enum.Parse(typeof(T), value, true);
}StatusEnum MyStatus = EnumUtil.ParseEnum<StatusEnum>("Active");public static T ToEnum<T>(this string value)
{
return (T) Enum.Parse(typeof(T), value, true);
}
StatusEnum MyStatus = "Active".ToEnum<StatusEnum>();Context
Stack Overflow Q#16100, score: 2231
Revisions (0)
No revisions yet.