Reputation: 15249
I need to build a function that takes a parameter and passes it to the System.Web.Mvc.ViewDataDictionary
constructor. This is my code:
// this WORKS, but need to pass as parameter
var dic1 = new System.Web.Mvc.ViewDataDictionary { { "key", "value" } };
// this DOES NOT WORK
Test({ "key", "value" }); // I try do not have 'new Something({"", ""})'
function Test(object myParam) {
var dic2 = new System.Web.Mvc.ViewDataDictionary { myParam };
//...
}
Is there a way to pass the parameter like I did, without need to pass the entire
new System.Web.Mvc.ViewDataDictionary { { "key", "value" } }
as parameter to the Test
function?
PS. This is some test code explaining the problem
// WORKS
var dic1 = new System.Web.Mvc.ViewDataDictionary { { "key", "value" } };
// DOES NOT WORK
// A CASE
string[] myArr = { "key", "value" }; // OK
var dic2 = new System.Web.Mvc.ViewDataDictionary { myArr }; // NOK
// B CASE
KeyValuePair<string, object> myPair = {"key", "value"}; // NOK
var dic3 = new System.Web.Mvc.ViewDataDictionary { myPair }; // OK
PPS. multiple arguments case:
// WORKS
var dic1 = new ViewDataDictionary { { "key", "value" }, {"key2", "value2"} };
var dic2 = new ViewDataDictionary { (replace w/ one single obj/arr impossible?)};
Upvotes: 0
Views: 1680
Reputation: 4202
Unfortunately, it's not possible to achieve what you want because curly brackets can be used only for the collection initialization. The parser treats these curly brackets in a special way only if they are connected to the new
keyword. It parses them and generates a bunch of the Add
calls.
If you want to pass only key and value it can be done like this:
Test("key", "value");
void Test(string key, object value) {
var dic2 = new ViewDataDictionary { { key, value } };
//...
}
The ViewDataDictionary
contains a constructor which accepts another ViewDataDictionary
:
Test(new ViewDataDictionary { { key, value } });
void Test(ViewDataDictionary dictionary) {
var dic2 = new ViewDataDictionary(dictionary);
//...
}
If you need to add some values from one ViewDataDictionary
to another existing ViewDataDictionary
you could use the following code:
Test(new ViewDataDictionary { { key, value } });
void Test(ViewDataDictionary dictionary) {
var dic2 = new ViewDataDictionary();
// ... initialize dic2
foreach (var pair in dictionary)
{
dic2.Add(pair);
}
}
If there is a need to pass an array (of KeyValuePair
elements) to initialize the dictionary it can be done in this way:
Test(new[] { new KeyValuePair<string, object>("key1", "value1"),
new KeyValuePair<string, object>("key2", "value2") });
void Test(KeyValuePair<string, object>[] pairs) {
var dic2 = new ViewDataDictionary();
foreach (var pair in pairs)
{
dic2.Add(pair);
}
//...
}
Upvotes: 2