Generic Method for Parsing Value Type in C#

Summary

In this article I am going to explain how to create a generic method named GetValue() that can parse int, float, long, double data types. The method would parse any value objects passed through it and prevents throwing errors in case of invalid data. When invalid data is passed the method will return the default value of type passed.

Code Detailed

The int, long, float and double data types contains TryParse() and Parse() methods in common which are static. Our GetValue() method takes the object to be parsed and identifies the return type through Generic Argument T.

In case of errors like the TryParse or Parse methods are missing in the type T, an exception is thrown. In case of errors data errors like argument is null or invalid data the default(T) would be returned.

public T GetValue<T>(object obj)
{
    if (obj != null)
    {
        Type type = typeof(T);
 
        T value = default(T);
        var methodInfo = (from m in type.GetMethods(BindingFlags.Public | BindingFlags.Static)
                          where m.Name == "TryParse"
                          select m).FirstOrDefault();
 
        if (methodInfo == null)
            throw new ApplicationException("Unable to find TryParse method!");

        object result = methodInfo.Invoke(null, new object[] { obj, value });
        if ((result != null) && ((bool)result))
        {
            methodInfo = (from m in type.GetMethods(BindingFlags.Public | BindingFlags.Static)
                              where m.Name == "Parse"
                              select m).FirstOrDefault();

            if (methodInfo == null)
                throw new ApplicationException("Unable to find Parse method!");

            value = (T)methodInfo.Invoke(null, new object[] { obj });

            return (T)value;
        }
    }
 
    return default(T);
}

Invoking the Method

The following code can be used to invoke the above method:

int i = _util.GetValue<int>("123");

long j = _util.GetValue<long>("abcd");

float k = _util.GetValue<float>("100.01");

double l = _util.GetValue<double>("200.20");

Point of Note

.Net Reflection is used to implement this method. I would like to say that in case fast performance is required, this method is not advisable.