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ToNullable<> Generic String Extension

Converts a string to a primitive type T, or an enum type T. Faster than tryparse blocks. Easier to use, too. Very efficient. Uses generics so the code is cleaner and more robust than doing a separate convert method for each primitive type.

Source

/// <summary>
/// <para>More convenient than using T.TryParse(string, out T). 
/// Works with primitive types, structs, and enums.
/// Tries to parse the string to an instance of the type specified.
/// If the input cannot be parsed, null will be returned.
/// </para>
/// <para>
/// If the value of the caller is null, null will be returned.
/// So if you have "string s = null;" and then you try "s.ToNullable...",
/// null will be returned. No null exception will be thrown. 
/// </para>
/// </summary>
/// <typeparam name="T"></typeparam>
/// <param name="p_self"></param>
/// <returns></returns>
public static T? ToNullable<T>(this string p_self) where T : struct
{
    if (!string.IsNullOrEmpty(p_self))
    {
        var converter = System.ComponentModel.TypeDescriptor.GetConverter(typeof(T));
        if (converter.IsValid(p_self)) return (T)converter.ConvertFromString(p_self);
        if (typeof(T).IsEnum) { T t; if (Enum.TryParse<T>(p_self, out t)) return t;}
    }

    return null;
}

Example

int? numVotes = "123".ToNullable<int>();
decimal price = tbxPrice.Text.ToNullable<decimal>() ?? 0.0M;
PetTypeEnum petType = "Cat".ToNullable<PetTypeEnum>() ?? PetTypeEnum.DefaultPetType;
PetTypeEnum petTypeByIntValue = "2".ToNullable<PetTypeEnum>() ?? PetTypeEnum.DefaultPetType;
 
string thisWillNotThrowException = null;
int? nullsAreSafe = thisWillNotThrowException.ToNullable<int>();
// More examples here: https://github.com/Pangamma/PangammaUtilities-CSharp/blob/master/TestExamples/ToNullableStringExtensionTests.cs

Author: Taylor A Love

Submitted on: 23 mei 2016

Language: C#

Type: system.string

Views: 2185