static void Main(string[] args)
{
PlayContext context = new PlayContext();
Console.WriteLine("上海滩：");
context.Text = "O 2 E 0.5 G 0.5 A 3 E 0.5 G 0.5 D 3 E 0.5 G 0.5 A 0.5 O 3 C 1 O 2 A 0.5 G 1 C 0.5 E 0.5 D 3 ";
Expression exp = null;
while (context.Text.Length > 0)
{
string str = context.Text.Substring(0, 1);
switch (str)
{
case "O": exp = new Scale(); break;
case "C":
case "D":
case "E":
case "F":
case "G":
case "A":
case "B":
case "P": exp = new Note(); break;
}
exp.Interpret(context);
}
Console.ReadKey();
}
public void Interpret(PlayContext context)
{
if (context.Text.Length != 0)
{
//此方法用于将当前地演奏文本第一条命令获得命令字母和其参数值
//例如“O3 E0.5 G0.5 A3”
//则playKey为O，而playValue为3
string playKey = context.Text.Substring(0, 1);
context.Text = context.Text.Substring(2);
double playValue = Convert.ToDouble(context.Text.Substring(0, context.Text.IndexOf(' ')));
context.Text = context.Text.Substring(context.Text.IndexOf(' ') + 1);
Execute(playKey, playValue);
}
}