13.练习：修改密码
/// <summary>
/// 修改密码
/// </summary>
/// <param name="sender"></param>
/// <param name="e"></param>
private void button1_Click(object sender, EventArgs e)
{
string oldPwd = txtoldpwd.Text.Trim();
string newPwd1= txtnewpwd1.Text.Trim();
string newPwd2 = txtnewpwd2.Text.Trim();
if (oldPwd.Equals("888888"))
{
if (newPwd1.Equals(oldPwd))
{
MessageBox.Show("新密码与旧密码一样，重新输入！");
txtnewpwd1.Text = "";
}
else if (newPwd1.Equals(newPwd2))
{
MessageBox.Show("修改成功！");
}
else
{
MessageBox.Show("两次输入的新密码不一致！");
txtnewpwd1.Text = "";
txtnewpwd2.Text = "";
}
}
else
{
MessageBox.Show("旧密码不正确！");
txtoldpwd.Text = "";
txtnewpwd1.Text = "";
txtnewpwd2.Text = "";
}
}
13 练习：
/// <summary>
/// 统计ListBox中的最高得分者的姓名和分数
/// </summary>
/// <param name="sender"></param>
/// <param name="e"></param>
private void btnresult_Click(object sender, EventArgs e)
{
string[] lines= txtScore.Lines;
int maxScore=-1;
string maxName = "";
for (int i = 0; i < lines.Length; i++)
{
string[] str=lines[i].Split('=');
string name = str[0];//姓名
string strScore = str[1];//分数
int score = Convert.ToInt32(strScore);
if (score>maxScore)
{//更新最大成绩学员的姓名和分数
maxName = name;
maxScore = score;
}
}
MessageBox.Show(string.Format("最高得分者是{0},得分为{1}",maxName,maxScore));
}
14 练习：
/// <summary>
/// 四则运算
/// </summary>
/// <param name="sender"></param>
/// <param name="e"></param>
private void button1_Click(object sender, EventArgs e)
{
string num1 = txtNum1.Text.Trim();
string num2 = txtNum2.Text.Trim();
int i1, i2;
//转换成int
if (!int.TryParse(num1,out i1))
{
MessageBox.Show("第一个数不合法");
txtNum1.Text = "";
}
else if (!int.TryParse(num2,out i2))
{
MessageBox.Show("第二个数不合法");
txtNum2.Text = "";
}
else
{
switch (cbOper.SelectedIndex)
{
case 0: //+
MessageBox.Show(string.Format("{0}+{1}={2}", i1, i2, i1 + i2));
break;
case 1: //-
MessageBox.Show(string.Format("{0}-{1}={2}", i1, i2, i1 - i2));
break;
case 2: //*
MessageBox.Show(string.Format("{0}*{1}={2}", i1, i2, i1 *i2));
break;
case 3: // /
if (i2==0)
{
MessageBox.Show(string.Format("第二个数不能为0"));
}
else
{
MessageBox.Show(string.Format("{0}/{1}={2}", i1, i2, i1 / i2));
}
break;
default:
throw new Exception("不合法运算符");
}
}
}
15练习：
/// <summary>
/// 省市选择关联器
/// </summary>
/// <param name="sender"></param>
/// <param name="e"></param>
private void cbCity_SelectedIndexChanged(object sender, EventArgs e)
{
List<string> list = new List<string>();
string[] anhui = {"合肥","安庆","蚌埠" };
string[] guangdong = { "广州","深圳" };
string[] shanghai = { "场圃" };
cbCountry.Items.Clear();//清空之前数据
switch (cbCity.SelectedIndex)
{
case 0: //安徽
cbCountry.Items.AddRange(anhui);
break;
case 1: //广东
cbCountry.Items.AddRange(guangdong);
break;
case 2: //上海
cbCountry.Items.AddRange(shanghai);
break;
default:
break;
}
}