Pass a method as a parameter to another method

Question

I am having a method called LoadData which gets data from DataBase and fills a DataGridView.

I am using a Stopwatch to measure how long my method takes to finish it's job as below :

private void btnLoadData_Click(object sender, EventArgs e)
{
    var sw = new System.Diagnostics.Stopwatch();
    sw.Start();
    LoadData ();
    sw.Stop();
    ShowTakenTime(sw.ElapsedMilliseconds);
}

I want something that can do The following :

private void MeasureTime(Method m)
{
    var sw = new System.Diagnostics.Stopwatch();
    sw.Start();
    m.Invoke();
    sw.Stop();
    ShowTakenTime(sw.ElapsedMilliseconds);
}

so that I can pass the LoadData method to it and it does the rest for me.

MeasureTime(LoadData());

How can I do that?

Answer 1

For a method without parameters and returning void, you can use Action:

    private void MeasureTime(Action m)
    {
        var sw = new System.Diagnostics.Stopwatch();
        sw.Start();
        m();
        sw.Stop();
        ShowTakenTime(sw.ElapsedMilliseconds);
    }

If you have some parameters or a return type, use Func

Answer 2

If you want to pass parameters to your Method m, use an Action<...>, for example if you want to pass an int and a string to your Method, use Action<int,string>

private void MeasureTime(Action<int, string> m)
{
   var sw = new System.Diagnostics.Stopwatch();
   sw.Start();
   m(42, "Hello World");
   sw.Stop();
   ShowTakenTime(sw.ElapsedMilliseconds);
}

If you need to access the return value of your Method, use Func<...>:

private void MeasureTime(Func<int, string, string> m)
{
   var sw = new System.Diagnostics.Stopwatch();
   sw.Start();
   var result = m(42, "Hello World");
   sw.Stop();
   ShowTakenTime(sw.ElapsedMilliseconds);
}