问题
I have this following list:
var myList = new List<KeyValuePair<string, object>>();
And this function:
public void Test(params KeyValuePair<string, object>[] list)
How can I do a conversion of the list to params when using the function? Like that:
Test(myList);
回答1:
You method declaration KeyValuePair<string, object>[] list
states that it will accept an array so you need to convert your list to array like this
Test(myList.ToArray());
回答2:
Given the original question, I think it's worth clarifying how the params
keyword functions.
It has to be a decorator on a 1D array, and simply allows an alternate syntax for calling the function.
For example if we have a string concatenation function:
public string Test(string[] names) {
return String.Join(",", names);
}
This can be called using
Test(new[] { "Fred", "Wilma", "Pebbles"});
but the inclusion of the params
keyword simply allows a friendlier looking calling syntax:
public string Test(params string[] names) {
return String.Join(",", names);
}
Test("Fred", "Wilma", "Pebbles");
I'm not a huge fan of the params
keyword, but I do sometimes use it to make calling code more readable (as in this example).
So when the OP asks "How can I do a conversion of the list to params?", the underlying truth is that you don't, as params is not a type and is simply a "syntactical sugar" feature to give an alternative syntax for passing in an array.
回答3:
You should convert the list to form which is accepted as parameter. In this case convert List to Array
Hence,
var arrayParam = mylist.ToArray();
Test(arrayParam);
来源:https://stackoverflow.com/questions/42923480/convert-list-to-params-c-sharp