Use LINQ and get field values by name

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Anton Bar - 03 Dec 2007 09:13 GMT

Hi all,

I have the following problem. I have a database table that I want to read
using LINQ and being able to access field values by name, like this:

var languages = from lg in context.SystemLanguages select lg;
foreach (SystemLanguage lang in languages)
{
// now I'd like to do smth like this:
string name = lang.Field(sFieldName);
.........
}

The problem is that the "sFieldName" string is built dynamically, so I
cannot use the predefined strongly typed properties!!!

Any bright ideas?

Thanks in advance,
Anton.

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Frans Bouma [C# MVP] - 03 Dec 2007 10:18 GMT

> Hi all,
>
[quoted text clipped - 14 lines]
>
> Any bright ideas?

    TypeDescriptor.GetProperties(typeof(SystemLanguage))

    this will get you property descriptors. You can use a property
descriptor with 'lang' to obtain a property's value by calling GetValue
on the property descriptor object.

    So you do something like:
PropertyDescriptorCollection properties =
TypeDescriptor.GetProperties(typeof(SsytemLanguage));
foreach(SystemLanguage lang in languages)
{
    string name = (string)properties[sFieldName].GetValue(lang);
}

    It's not as fast as reading normal properties, but it shows you what
the possibilities are. :)

        FB

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Use LINQ and get field values by name

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