I'm trying to create some dynamic ExpandoObject
. I've encountered a certain problem.
As I don't know what the name of these different properties in my objects should be, I can't do like this:
var list = new ArrayList();
var obj = new ExpandoObject();
obj.ID = 1,
obj.Product = "Pie",
obj.Days = 1,
obj.QTY = 65
list.Add(obj);
Let me explain my situation: I wish to get data from a random DB (I don't know which, but building a connection string from the information I get from the UI), therefore I don't know what data I need to get. This could be an example of a DB table
TABLE Sale
This could be another exmaple:
TABLE Foobar
As you see, I don't know what the DB looks like (this is 100% anonymous, therefore it needs to be 100% dynamic), and the data I want to return should look like a well constructed JSON, like so:
[
{
"ID": 1,
"Product": "Pie"
"Days": 1,
"QTY": 65
},
{
"ID": 2,
"Product": "Melons"
"Days": 5,
"QTY": 12
}
]
Or, with the other example:
[
{
"ID": 1,
"Days": 2,
"QTY": 56,
"Product_Id": 5,
"Department_Id": 2
}
{
"ID": 2,
"Days": 6,
"QTY": 12,
"Product_Id": 2,
"Department_Id": 5
}
]
I've tried working with these ExpandoObject
s, but can't seem to make it work, as I can't do what's illustrated in the top of this question (I don't know the names of the properties). Is there a way for me to say something like:
var obj = new ExpandoObject();
var propName = "Product";
var obj.propName = "Pie"
Console.WriteLine("Let's print!: " + obj.Product);
//OUTPUT
Let's print!: Pie
Does anyone have a solution, og simply guidance to a structure, that might solve this situation?
Rather than creating an ExpandoObject
or some other dynamic type, you could create a List<Dictionary<string, object>>
where each Dictionary<string, object>
contains the name/value pairs you want to serialize. Then serialize to JSON using Json.NET (or JavaScriptSerializer
, though that is less flexible):
var list = new List<Dictionary<string, object>>();
// Build a dictionary entry using a dictionary initializer: https://msdn.microsoft.com/en-us/library/bb531208.aspx
list.Add(new Dictionary<string, object> { { "ID", 1 }, {"Product", "Pie"}, {"Days", 1}, {"QTY", 65} });
// Build a dictionary entry incrementally
// See https://msdn.microsoft.com/en-us/library/xfhwa508%28v=vs.110%29.aspx
var dict = new Dictionary<string, object>();
dict["ID"] = 2;
dict["Product"] = "Melons";
dict["Days"] = 5;
dict["QTY"] = 12;
list.Add(dict);
Console.WriteLine(JsonConvert.SerializeObject(list, Formatting.Indented));
Console.WriteLine(new JavaScriptSerializer().Serialize(list));
The first outputs:
[ { "ID": 1, "Product": "Pie", "Days": 1, "QTY": 65 }, { "ID": 2, "Product": "Melons", "Days": 5, "QTY": 12 } ]
The second outputs the same without the indentation:
[{"ID":1,"Product":"Pie","Days":1,"QTY":65},{"ID":2,"Product":"Melons","Days":5,"QTY":12}]