我想用c#做一个超市收银机的小程序
public partial class Form3 : Form { public Form3() { InitializeComponent(); } DataTable dt = new DataTable(); private void button1_Click(object sender, EventArgs e) { var ID = textBox1.Text.Trim(); var Count = String.IsNullOrEmpty(textBox2.Text.Trim()) ? 0 : Convert.ToInt32(textBox2.Text.Trim()); var row = dt.Select(String.Format(“ID = ‘{0}’”, ID)); if (row!=null && row.Count() > 0) { row[0][“Count”] = Convert.ToInt32(row[0][“Count”]) + Count; } else { dt.Rows.Add(new object[] { ID, Count }); } dataGridView1.DataSource = dt; } private void Form3_Load(object sender, EventArgs e) { dt.Columns.Add(“ID”, typeof(String)); dt.Columns.Add(“Count”, typeof(Int32)); dataGridView1.DataSource = dt; } }控件如上面，什麼名字都不用改，直接写了button1的Click事件。设定全局DataTable。没了！
一、写一个超市收银机结账程序
#include
#include
int main()
{
int i=0;
double sum=0,price,in;
printf(“请输入价格:\n”);
do{
scanf(“%lf”,&price);
sum+=price;
}
while(price!=0);
printf(“总金额:%.1f\n”,sum);
printf(“请输入收款金额:\n”);
scanf(“%lf”,&in);
printf(“找零金额:%.1f\n”,in-sum);
}
