Connected service property should lead to datasource

Question

0.00/5 (No votes)

See more:

Hi everyone,

I have a connected services and use properties to retrieve data from EF6.
In a testapplication I can create a list with these propertyname to fill a combobox

ConnectedDataServices.DataServiceContext.GetType().GetRuntimeProperties().Select(x => x.Name).ToList();

I can get the vales from he property but as type object instead of the original type ConcurrentBag<>.

But how do I get the contents or values of the object to bind the concurrentbag desired?

What I have tried:

var selectedProp = comboBox1.SelectedItem.ToString();

            PropertyInfo propInfo = _availableProps.FirstOrDefault(x => x.Name == selectedProp);
            var results = propInfo.GetValue(ConnectedDataServices.DataServiceContext, null);
            Type type = results.GetType();
            dataGridView1.DataSource = results;
            dataGridView1.Refresh();

results is now object type instead of ConcurrentBag<entity>

Posted 25-Jun-18 22:33pm

Herman<T>.Instance

Updated 26-Jun-18 4:46am

v3

Add a Solution

Comments

Richard Deeming 26-Jun-18 9:31am

The compile-time type of result will be object; but the run-time type will be whatever type the property returns.

The DataSource property takes an object, so I'm struggling to see what the problem is.

Herman<T>.Instance 26-Jun-18 10:30am

The problem was that I used ConcurrentBag in my WCF. Changing to a List<> object solved the problem. DataGridView cannot show data from ConcurrentBAG<> objects I suppose.

Richard Deeming 26-Jun-18 10:34am

That sounds about right. The documentation[^] says that the DataSource requires an object that implements either IList, IListSource, IBindingList, or IBindingListView. But ConcurrentBag[^] doesn't implement any of those interfaces.

1 solution

Add a Solution

Add your solution here

Treat my content as plain text, not as HTML

Preview 0

…

Existing Members

Sign in to your account

...or Join us

Download, Vote, Comment, Publish.

Your Email
Password
Forgot your password?

Your Email
This email is in use. Do you need your password?
Optional Password

I have read and agree to the Terms of Service and Privacy Policy
Please subscribe me to the CodeProject newsletters

When answering a question please:

Read the question carefully.
Understand that English isn't everyone's first language so be lenient of bad spelling and grammar.
If a question is poorly phrased then either ask for clarification, ignore it, or edit the question and fix the problem. Insults are not welcome.
Don't tell someone to read the manual. Chances are they have and don't get it. Provide an answer or move on to the next question.

Let's work to help developers, not make them feel stupid.

This content, along with any associated source code and files, is licensed under The Code Project Open License (CPOL)

Richard Deeming · Accepted Answer · 2018-06-26T04:48:00

If you're using a recent version of the C# compiler, you can use a pattern-matching switch to make sure the property value is of the correct type:

C#

switch (results)
{
    case null:
    case IList _:
    case IListSource _:
    {
        // Includes IBindingList and IBindingListView
        dataGridView1.DataSource = results;
        break;
    }
    case ICollection collection:
    {
        dataGridView1.DataSource = new ArrayList(collection);
        break;
    }
    case IEnumerable sequence:
    {
        dataGridView1.DataSource = sequence.Cast<object>().ToList();
        break;
    }
    default:
    {
        // Not a supported type:
        dataGridView1.DataSource = null;
        break;
    }
}

It would be simple enough to convert this to work in an older compiler, but it wouldn't be as clean. :)