C＃将参数传递给委托

Question

Hello I have a little problem with C# syntax...

Right now I'm passing four parameters to a method called WriteConfig

 var task = fac.StartNew(() => { vault.WriteConfig(fileName, id, queue, DeleteUploadQueue); });

DeleteUploadQueue is a delegate and gets called with id as parameter inside WriteConfig . What I want to do is pass id to DeleteUploadQueue outside instead of inside WriteConfig so that I dont have to pass id to WriteConfig .

WriteConfig looks like this:

 public void WriteConfig(string fileName, int id, BlockingCollection<byte[]> queue, Action<int> deleteFunc)

But I cannot come up with the correct syntax for this.

Thank you for your help

Answer 1

Assuming you change the signature to this:

public void WriteConfig(string fileName, BlockingCollection<byte[]> queue, Action deleteFunc)

You could write

var task = fac.StartNew(() => { vault.WriteConfig(fileName, queue,  ()=> DeleteUploadQueue(id)); });

Answer 2

sounds like you want

var task = fac.StartNew(() => { vault.WriteConfig(fileName, id, queue,
    () => DeleteUploadQueue(id)); })

so if you also want to change WriteConfig to not take an int id , then you'll need to make the deleteFunc into Action instead of Action<int> , so:

public void WriteConfig(string fileName, BlockingCollection<byte[]> queue,
    Action deleteFunc)

and

var task = fac.StartNew(() => { vault.WriteConfig(fileName, queue,
    () => DeleteUploadQueue(id)); })

Answer 3

You´re looking from the whrong point. You should provide the arguments for the delegate when you´re calling it, not when you´re defining it. I suppose this happens within your WriteConfig -method:

WriteConfig(string fileName, int id, BlockingCollection<byte[]> queue, Action<int> deleteFunc)
{
    /* ... */
    deleteFunc(id) <------- provide your args here
}

Providing the parameter to your delegate happens at the line marked with <------- . Yimply provide the id :

deleteFunc(id);