int a, b;
string op;
int result;
Random rnd = new Random();
private void btnNew_Click(object sender, System.EventArgs e)
{
a = rnd.Next( 9 ) + 1;
b = rnd.Next( 9 ) + 1;
int c = rnd.Next( 4 );
switch( c )
{
case 0: op="+"; result=a+b; break;
case 1: op="-"; result=a-b; break;
case 2: op="*"; result=a*b; break;
case 3: op="/"; result=a/b; break;
}
lblA.Text=a.ToString();
lblB.Text=b.ToString();
lblOp.Text=op;
txtAnswer.Text="";
}
private void btnJudge_Click(object sender, System.EventArgs e)
{
string str = txtAnswer.Text;
double d = double.Parse( str );
string disp = "" + a + op + b+"="+ str +" ";
if( d == result ) // if( Math.Abs(d-result)< 1e-3 )
disp += "☆";
else
disp += "╳";
lstDisp.Items.Add( disp );
}
}