I am getting lost in the many answers and examples here (Pass Method as Parameter using C#) about passing functions.

At the moment I have this:

private void AddWeekToHistory(ref XDocument xdoc, MSAHistoryWeek historyWeek)
{
   // Do stuff
    DetectStudentItemDescriptionAndType(studentItem,
                                                        bFirstStudent,
                                                        iClass,
                                                        out string strDesc,
                                                        out string strType);
   // Do stuff
}
private void DetectStudentItemDescriptionAndType(MSAHistoryItemStudent studentItem, bool bFirstStudent, int iClass, out string strDesc, out string strType)
{
    // Do stuff
}

I want to change AddWeekToHistory so that it can be passed a DetectStudentItemDescriptionAndType function. This is because I want to add a second version of that function that will use different logic (same parameters).

Ultimately I want to call AddWeekToHistory(ref xdoc, historyWeek, [name-of-func]);.

I understand from the answers that since I am using a void function that I should use Action. But I was getting lost in teh answers because the method in the original question there was passed a parameter and yet in the examples of running the passed function they did not actually pass parameters.

So rather than confuse an existing question I have asked a new one. What changes are needed for me to support passing DetectStudentItemDescriptionAndType and its variants (same attributes) as a function to AddWeekToHistory?

CodePudding user response：

You can't use any of the Action<...> delegates for a method with ref or out parameters. You will need a custom delegate instead:

public delegate void DetectStudentItemDescriptionAndTypeDelegate(MSAHistoryItemStudent studentItem, bool bFirstStudent, int iClass, out string strDesc, out string strType);

private void AddWeekToHistory(ref XDocument xdoc, MSAHistoryWeek historyWeek, DetectStudentItemDescriptionAndTypeDelegate detect)
{
    // Do stuff
    detect(studentItem,
        bFirstStudent,
        iClass,
        out string strDesc,
        out string strType);
   // Do stuff
}

private void DetectStudentItemDescriptionAndType(MSAHistoryItemStudent studentItem, bool bFirstStudent, int iClass, out string strDesc, out string strType)
{
    // Do stuff
}

AddWeekToHistory(xdoc, historyWeek, DetectStudentItemDescriptionAndType);

Delegates - C# Programming Guide