loop through object and get properties

Question

i have a method that returns a list of operating system properties. Id like to loop through the properties and do some processing on each one.All properties are strings

How do i loop through the object

C#

// test1 and test2 so you can see a simple example of the properties - although these are not part of the question
String test1 = OS_Result.OSResultStruct.OSBuild;
String test2 = OS_Result.OSResultStruct.OSMajor;

// here is what i would like to be able to do
foreach (string s in OS_Result.OSResultStruct)
{
    // get the string and do some work....
    string test = s;
    //......

}

score 14 · Accepted Answer · edited May 23 '17 at 12:08

14

You can do it with reflection:

// Obtain a list of properties of string type
var stringProps = OS_Result
    .OSResultStruct
    .GetType()
    .GetProperties()
    .Where(p => p.PropertyType == typeof(string));
foreach (var prop in stringProps) {
    // Use the PropertyInfo object to extract the corresponding value
    // from the OS_Result.OSResultStruct object
    string val = (string)prop.GetValue(OS_Result.OSResultStruct);
    ...
}

[EDIT by Matthew Watson] I've taken the liberty of adding a further code sample, based on the code above.

You could generalise the solution by writing a method that will return an IEnumerable<string> for any object type:

public static IEnumerable<KeyValuePair<string,string>> StringProperties(object obj)
{
    return from p in obj.GetType().GetProperties()
            where p.PropertyType == typeof(string)
            select new KeyValuePair<string,string>(p.Name, (string)p.GetValue(obj));
}

And you can generalise it even further with generics:

public static IEnumerable<KeyValuePair<string,T>> PropertiesOfType<T>(object obj)
{
    return from p in obj.GetType().GetProperties()
            where p.PropertyType == typeof(T)
            select new KeyValuePair<string,T>(p.Name, (T)p.GetValue(obj));
}

Using this second form, to iterate over all the string properties of an object you could do:

foreach (var property in PropertiesOfType<string>(myObject)) {
    var name = property.Key;
    var val = property.Value;
    ...
}

edited May 23 '17 at 12:08

Community

1
1

answered Mar 23 '13 at 11:23

Sergey Kalinichenko

714,442
84
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on the line "string val = (string)prop.GetValue(OS_Result.OSResultStruct);" - i get the Error No overload for method 'GetValue' takes 1 arguments – user1438082 Mar 23 '13 at 11:29
1

@user1438082 It looks like you're using .NET 4.0 or earlier; try the older version `GetValue(OS_Result.OSResultStruct, null)` then. – Sergey Kalinichenko Mar 23 '13 at 11:36
hi, nearly - its returning the property but i am looking for the name e.g OSBuild and OSMajor for the example in the question. – user1438082 Mar 23 '13 at 11:50
1

@user1438082 That would be `prop.Name` then. – Sergey Kalinichenko Mar 23 '13 at 11:57
1

Nice snippet. I'll be grabbing a copy of that, then. *hoick* ;) – Matthew Watson Mar 23 '13 at 12:32
2

@MatthewWatson Thanks for the edit! I changed the output to `IEnumerable>` to give users of your methods access to property names, in addition to the property values. – Sergey Kalinichenko Mar 23 '13 at 13:11
1

That's even better! :) – Matthew Watson Mar 23 '13 at 13:28

score 2 · Answer 2 · answered Mar 23 '13 at 11:21

2

You can use Reflection to loop the GetProperties Resullt:

OS_Result.OSResultStruct.GetType().GetProperties()

answered Mar 23 '13 at 11:21

Muhammad Omar ElShourbagy

6,718
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32
50

loop through object and get properties

2 Answers2

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