黑马程序员--WinForm进阶自学总结

---------------------- Windows Phone 7手机开发、.Net培训、期待与您交流！ ----------------------

计算两个数的和、累加器

	private void button1_Click(object sender, EventArgs e)
        {
            string str1 = textBox1.Text;
            string str2 = textBox2.Text;
            int i1, i2;
            if(!int.TryParse(str1,out i1))
            {
                MessageBox.Show("第一个数不是合法的整数");
                return;//不要忘了return
            }
            if (int.TryParse(str2, out i2) == false)
            {
                MessageBox.Show("第而个数不是合法的整数");
                return;
            }
            int i3 = i1 + i2;
            textBox3.Text = Convert.ToString(i3);
        }

        private void button2_Click(object sender, EventArgs e)
        {
            string str1 = textBox4.Text;
            string str2 = textBox5.Text;
            int i1, i2;
            if (!int.TryParse(str1, out i1))//尝试转换 将str1尝试转换成 i1，转换成功返回值为true 失败返回值为false
            {
                MessageBox.Show("数字1格式错误！");
                return;//不能丢 错误了就不它他再继续往下执行
            }
            if (!int.TryParse(str2, out i2))
            {
                MessageBox.Show("数组2格式错误！");
                return;
            }
            if (i1 >= i2)
            {
                MessageBox.Show("第二个数要大于第一个数！");
                return;
            }
            int sum = 0;
            for (int i = i1; i <= i2; i++)
            {
                sum += i;
            }
            textBox6.Text = Convert.ToString(sum);
        }

ComboBox

	private void button1_Click(object sender, EventArgs e)
        {
            MessageBox.Show(Convert.ToString(comboBox1.SelectedIndex));//序号 从0开始
            MessageBox.Show(Convert.ToString(comboBox1.SelectedValue));//数据库中用到
            MessageBox.Show(Convert.ToString(comboBox1.SelectedText));//数据库中用到
            MessageBox.Show(Convert.ToString(comboBox1.SelectedItem));//选中的 项
        }

        private void btnResult_Click(object sender, EventArgs e)
        {
            string str1 = txtNum1.Text;
            string str2 = txtNum2.Text;
            int i1 = Convert.ToInt32(str1);
            int i2 = Convert.ToInt32(str2);
            int result;

            switch (cbx运算符.SelectedIndex)
            { 
                case 0:
                    result = i1 + i2;
                    break;
                case 1:
                    result = i1 - i2;
                    break;
                case 2:
                    result = i1 * i2;
                    break;
                case 3:
                    if (i2 == 0)//细节决定成败！
                    {
                        MessageBox.Show("0不能当除数！");
                        return;
                    }
                    result = i1 / i2;
                    break;
                default://防患于未然！
                    throw new Exception("未知的运算符！");
            }
            txtResult.Text = Convert.ToString(result);
        }

        private void comboBox1_SelectedIndexChanged(object sender, EventArgs e)
        {
            MessageBox.Show(Convert.ToString(comboBox1.SelectedItem));
        }

        private void cbxProvince_SelectedIndexChanged(object sender, EventArgs e)
        {
            cbxCity.Items.Clear();//清空旧数据
            string prov = Convert.ToString(cbxProvince.SelectedItem);
            if (prov == "山东")//1.选择了一个省，选择对应的市，再换个省的时候刚才选得 市，并没有删除。怎么删除   方法：换成DropDownList样式
            {
                cbxCity.Items.Add("潍坊");
                cbxCity.Items.Add("临沂");
                cbxCity.Items.Add("青岛");
            }
            if (prov == "河南")
            {
                cbxCity.Items.Add("郑州");
                cbxCity.Items.Add("三门峡");
                cbxCity.Items.Add("洛阳");
            }
            if (prov == "辽宁")
            {
                cbxCity.Items.Add("沈阳");
                cbxCity.Items.Add("鞍山");
                cbxCity.Items.Add("本溪");
            }
        }
        //只能选不能填 属性DropDownStyle设置成 DropDownList

邮箱分析：

	private void button1_Click(object sender, EventArgs e)
        {
            string email = textBox1.Text;
            string[] strs = email.Split('@');
            if (strs.Length != 2)
            {
                MessageBox.Show("非法的Email地址！");
                return;
            }
            textBox2.Text = strs[0];
            textBox3.Text = strs[1];
        }

多行文本框练习：

	private void btnResult_Click(object sender, EventArgs e)
        {
            //string s = txtScore.Text; //方法1：按照\r\n进行split
            string[] lines = txtScore.Lines;
            string maxName = "";
            int maxScore = -1;
            foreach (string line in lines)
            {
                string[] strs = line.Split('=');
                string name = strs[0];
                string strScore = strs[1];
                int score = Convert.ToInt32(strScore);
                if (score > maxScore)
                {
                    maxName = name;
                    maxScore = score;
                }
            }
            MessageBox.Show(string.Format("{0}是第一名，成绩{1}",maxName,maxScore));
        }

根据年龄(身份证)显示图片：

	private void button1_Click(object sender, EventArgs e)
        {
            string identity = textBox1.Text;

            pictureBox1.Visible = true;//不管用 在属性中设置
            string strYear = identity.Substring(6, 4);
            int Year = Convert.ToInt32(strYear);
            if ((DateTime.Now.Year - Year) > 18)
            {
                pictureBox1.Visible = true;
            }
            else
            {
                pictureBox1.Visible = false;
            }
        }

        private void button2_Click(object sender, EventArgs e)
        {
            //向左滚动
            string str = textBox2.Text;
            char first = str[0];
            string last = str.Substring(1);
            textBox2.Text = last + first;
        }

        private void button3_Click(object sender, EventArgs e)
        {
            //向又滚动
            string str = textBox2.Text;
            char lastC = str.Substring(str.Length - 1)[0];
            string last = str.Substring(0, str.Length - 1);
            textBox2.Text = lastC + last;
        }

文本框练习：

	private void button1_Click(object sender, EventArgs e)
        {
            textBox1.AppendText(DateTime.Now.ToString() + "\n");//给多行文本附加文本
            //textBox1.Text += DateTime.Now.ToString() + "\n"; //效率低()
        }

用户登录练习：

 

 	//类字段
        private int ErrorTimes = 0;

        private void btnLogin_Click(object sender, EventArgs e)
        {
            string userName = txtUserName.Text.Trim();
            string pwd = txtPwd.Text;
            if (userName.Equals("admin", StringComparison.OrdinalIgnoreCase) && pwd == "888")//忽略大小写。
            {
                MessageBox.Show("登陆成功！");
            }
            else
            {
                //int i = 0;
                //i++;
                //if (i >= 3)
                //{
                //    MessageBox.Show("错误次数过多！程序即将退出！");
                //    Application.Exit();
                //}
                ErrorTimes++;//局部变量每次运行完毕变量的值都会被销毁，下次再运行，会重新初始化。而类字段，只要是一个对象，那么只要对象不销毁，就会一直保持对象的字段值。
                if (ErrorTimes >= 3)
                {
                    MessageBox.Show("错误次数过多！程序即将退出！");
                    Application.Exit();
                }
                MessageBox.Show("登录失败");
            }
        }

        private void btnModify_Click(object sender, EventArgs e)
        {
            string oldPwd = txtOldPwd.Text;
            string newPwd = txtNewPwd.Text;
            string newPwd1 = txtNewPwd1.Text;

            if (oldPwd != "888")
            {
                MessageBox.Show("旧密码错误！");
                return;
            }

            if (newPwd != newPwd1)
            {
                MessageBox.Show("两次输入密码不一致！");
                return;
            }

            if (newPwd == oldPwd)
            {
                MessageBox.Show("旧密码和新密码不能一样！");
                return;
            }

            MessageBox.Show("修改成功！");
        }

----------------------  Windows Phone 7手机开发 、 .Net培训 、期待与您交流！ ----------------------