用戶登錄界面.cs

效果圖：

代碼如下：
using System;
using System.Collections.Generic;
using System.ComponentModel;
using System.Data;
using System.Drawing;
using System.Linq;
using System.Text;
using System.Threading.Tasks;
using System.Windows.Forms;

namespace denglu
{
    public partial class Form1 : Form//新建window窗體
    {
        public Form1()
        {
            InitializeComponent();
        }

        private void Form1_Load(object sender, EventArgs e)//找到Form1的Load事件雙擊得出
        {

        }

        private void tb1_Leave(object sender, EventArgs e)
        {//找到上面的第一個文本框tb1的Leave事件雙擊得出
            if (tb1.Text.Length < 5)
            {
                l3.Text = "用戶名不能小於5位！";
                tb1.Text = "";
                tb1.Focus();
            }
        }


        private void tb2_Leave(object sender, EventArgs e)
        {//找到上面的第二個文本框tb2的Leave事件雙擊得出
            if (tb2.Text.Length < 5)
            {
                l3.Text = "密碼不能小於5位";
                tb2.Text = "";
                tb2.Focus();
            }
        }

        private void tb1_KeyPress(object sender, KeyPressEventArgs e)//找到上面的第一個文本框tb1的KeyPress事件雙擊得出
        {
            if (e.KeyChar < 65 || (e.KeyChar > 90 && e.KeyChar < 97) || e.KeyChar > 122)
            {
                l3.Text = "用戶名只能爲大小寫字母！";
                tb1.Text = "";
                tb1.Focus();
            }
        }

        private void tb2_KeyPress(object sender, KeyPressEventArgs e)
        {
            if (e.KeyChar < 49 || e.KeyChar > 57)
            {
                l3.Text = "密碼只能爲數字";
                tb2.Text = "";
                tb2.Focus();
            }
        }
        private void b1_Click(object sender, EventArgs e)
        {
            if (tb2.Text.Length < 5)
            {
                l3.Text = "密碼不能小於5位！";
                tb2.Text = "";
                tb2.Focus();
            }
            else
            {
                if (tb1.Text.Equals("abcdef") && tb2.Text.Equals("123456789"))
                {
                    l3.Text = "登錄成功！";
                }
                else
                {
                    l3.Text = "用戶名或者密碼錯誤！";
                }
            }
        }
        private void b2_Click(object sender, EventArgs e)
        {
            tb1.Text = "";
            tb2.Text = "";
            tb1.Focus();
        }
    }
}