Several functions used in previous projects

You may be able to use the following for review.

//
// Function: converts all content in ListBox into a string, and each field is separated by commas (,).
//
// Parameter: Lists, The ListBox. items to be converted
//
// Return value: converted string
//
Public string ListToString (ListItemCollection Lists)
{
String result = "";
For (int I = 0; I <Lists. Count; I ++)
{
If (I = 0)
{
Result = Lists [I]. Text;
}
Else
{
Result = result + "," + Lists [I]. Text;
}
}
Return result;
}

//
// Function: Convert all content in string to ListItemCollection to bind to Listbox
//
// Parameter: str, the string to be converted
//
// Return value: converted ListItemCollection
//
Public ListItemCollection StringToList (string str)
{
ListItemCollection lists = new ListItemCollection ();
If (str = "") // the string is empty
{
ErrPosition = "ListItemCollection ";
ErrMsg = "the string is empty ";
}
Else if (str. IndexOf (",") = 0) // The first place is ","
{
ErrPosition = "ListItemCollection ";
ErrMsg = "first ,";
}
Else if (str. Substring (str. Length-1, 1) = ",") // The last bit is ","
{
ErrPosition = "ListItemCollection ";
ErrMsg = "tail bit ,";
}
Else
{
While (str. IndexOf (",")> 0)
{
Int position = str. IndexOf (",");
Lists. Add (str. Substring (0, position ));
Str = str. Remove (0, position + 1 );
}
Lists. Add (str );
}
Return lists;
}

//
// Function: Move the selected data in the source ListBox to the target ListBox.
//
// Parameter: FromLists, source ListBox
//
Public static void MoveListBoxSelectedItem
(ListItemCollection FromLists, ListItemCollection ToLists)
{
For (int I = FromLists. Count-1; I> = 0; I --)
{
If (FromLists [I]. Selected)
{
FromLists [I]. Selected = false;
ToLists. Add (FromLists [I]);
FromLists. Remove (FromLists [I]);
}
}
}

//
// Function: Move all data in the source ListBox to the target ListBox
//
// Parameter: FromLists, source ListBox
//
Public static void MoveListBoxAllItem
(ListItemCollection FromLists, ListItemCollection ToLists)
{
For (int I = FromLists. Count-1; I> = 0; I --)
{
FromLists [I]. Selected = false;
ToLists. Add (FromLists [I]);
FromLists. Remove (FromLists [I]);
}
}

//
// Function: Enter the set of days in which the month is returned.
//
// Parameter: YYYY, MM Month
//
// Return value: ArrayList of the number of days of the month
//
Public static ArrayList GetDaysInMonth (int YYYY, int MM)
{
Int day = DateTime. DaysInMonth (YYYY, MM );
ArrayList days = new ArrayList ();
For (int I = 1; I <= day; I ++)
{
Days. Add (I );
}
Return days;
}

//
// Function: Enter the set of selected days and return the minimum and maximum days.
//
// Parameter: dates. You can pass in Calendar. SelectedDates.
//
// Return value: ArrayList of two values. The first value is the minimum number of days, and the second value is the maximum number of days.
//
Public static ArrayList GetMinMaxDate (SelectedDatesCollection dates)
{
ArrayList Result = new ArrayList ();
DateTime min = new DateTime ();
DateTime max = new DateTime ();
For (int I = 0; I <dates. Count; I ++)
{
If (I> 0)
{
If (dates [I] <min)
{
Min = dates [I];
}
If (dates [I]> max)
{
Max = dates [I];
}
}
Else
{
Min = dates [I];
Max = dates [I];
}
}
Result. Add (min );
Result. Add (max );
Return Result;
}

When a function is called, ListItemCollection uses ListBox. Items as the parameter.