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c#.netreflectiontrim

Iterate through Object's own Strings & Trim each


I have multiple large objects which each have about 60 strings. I have to trim all those strings, and I'd like to do so without having to go this.mystring = this.mystring.Trim(). Instead, I'm looking for a way to automatically have each object discover its own strings and then perform the operation.

I know a little bit about reflection, but not enough, but I think this is possible?

Also, I'm not sure if this matters, but some string properties are read-only (only have a getter), so those properties would have to be skipped.

Help?


Solution

  • Well, it's easy enough to get all the properties, and find out which ones are strings and writable. LINQ makes it even easier.

    var props = instance.GetType()
                        .GetProperties(BindingFlags.Instance | BindingFlags.Public)
                        // Ignore non-string properties
                        .Where(prop => prop.PropertyType == typeof(string))
                        // Ignore indexers
                        .Where(prop => prop.GetIndexParameters().Length == 0)
                        // Must be both readable and writable
                        .Where(prop => prop.CanWrite && prop.CanRead);
    
    foreach (PropertyInfo prop in props)
    {
        string value = (string) prop.GetValue(instance, null);
        if (value != null)
        {
            value = value.Trim();
            prop.SetValue(instance, value, null);
        }
    }
    

    You may want to only set the property if trimming actually makes a difference, to avoid redundant computations for complex properties - or it may not be an issue for you.

    There are various ways of improving the performance if necessary - things like:

    • Simply caching the relevant properties for each type
    • Using Delegate.CreateDelegate to build delegates for the getters and setters
    • Possibly using expression trees, although I'm not sure whether they'd help here

    I wouldn't take any of those steps unless performance is actually a problem though.