Simple syntax to create a record/tuple to pass few objects as a single parameter?-CodePudding

Consider use case: I need to pass a parameter to QueueUserWorkItem:

ThreadPool.QueueUserWorkItem((o) =>
{
    var item = o as MyObject;
},
item);

Then requirements changed and I now need to pass 2 objects. So I would have to write something like:

ThreadPool.QueueUserWorkItem((o) =>
{
    var items = o as Tuple<MyObject,MyObject2>;
},
new Tuple<MyObject,MyObject2>(item1, item2));

Is there a cleaner way to achieve this in C# 9 ?

CodePudding user response：

You can use this overload if your target framework has it. Then you can do:

ThreadPool.QueueUserWorkItem(args => {
    var first = args.Item1; // it's of type string already
    var second = args.Item2; // this is int
}, ("a", 1), false);

Or:

ThreadPool.QueueUserWorkItem(args => {
    var first = args.first; // it's of type string already
    var second = args.second; // this is int
}, (first: "a", second: 1), false); // name parameters here instead of using Item1 Item2

And in single parameter case you don't need to cast type from object (this overload accepts generic Action<T> delegate).

CodePudding user response：

You can always leverage closures in C# lambdas and ingore passing parameter completely:

var item1 = ...;
var item2 = ...;
ThreadPool.QueueUserWorkItem(_ =>
{
    Console.WriteLine(item1);
    Console.WriteLine(item2);
});

Also personally I would consider switching to Task.Run instead of ThreadPool.QueueUserWorkItem (though there should be some considiration due to some differences in behaviour).