private void tank_Underflow(Object sender, TankEventArgs e)
{
string message = e.Message;
int deficency = e.Amount;
MessageBox.Show("Message: " + message + "\n" + "Deficency: " + deficency);
}
//method to add water to the tank
public void AddWater(int amount)
{
//as we add water, the current level could
//exceed the maxLevel. At that point, we need
//to alert or notify the client implies fire
//the Overflow event, which invokes the delegate
//object, and the delegate calls a method in the
//client.
if (amount + _currentLevel > _maxLevel)
{
if (Overflow != null) //check that a client has registered to this event
{
//We have exceeded the max, fire the event
int excess = Math.Abs(_maxLevel - (amount + _currentLevel));
string message = "Would cause the tank to overflow";
TankEventArgs te = new TankEventArgs(message, excess);
//Fire the event: same syntax as invoking a delegate
Overflow(this, te);
}
}
else
{
_currentLevel += amount;
}
}
//method that handles the Overflow event when it gets fired from the tank
//Must have the same signature as the delegate type (TankHandler)
private void tank_Overflow(Object sender, TankEventArgs e)
{
string message = e.Message;
int excess = e.Amount;
MessageBox.Show("Message: " + message + "\n" + "Excess: " + excess);
}
//method to use or remove water from the tank
public void UseWater(int amount)
{
if (_currentLevel - amount < _minLevel)
{
if (Underflow != null)
{
int deficiency = _minLevel - (amount - _currentLevel);
string message = "Would cause the tank to underflow";
TankEventArgs te = new TankEventArgs(message, deficiency);
Underflow(this, te);
}
}
else
{
_currentLevel -= amount;
}
}
