using System;
using System.Collections.Generic;
using System.ComponentModel;
using System.Data;
using System.Drawing;
using System.Linq;
using System.Text;
using System.Windows.Forms;
using System.Collections;
using System.Drawing.Drawing2D;
using System.Text.RegularExpressions;
namespace 窗体练习
{
/*********************************
* 1.用户名为空时，文本框变颜色
* 2.进入到用户名后，恢复为原来颜色
* 3.当用户名超过4位时，登录按钮不可用,并且提示
* 4.双击用户名文本框，登录按钮可用
* 5.当用户名超过6位时，弹出错误提示
* 6.按回车进入下一个文本框
* 7.关闭窗体时，弹出是否关闭的对话框
* 8.按ENter=按登录，按Esc=按退出
* 9.防止窗体在任务栏出现
* 10.去掉最大化或最小化按钮
* 11.默认最大化的显示窗体
* 12.设置显示窗体中屏幕的中间
* 13.鼠标经过用户名文本框附近出现提示语
* 14.修改登录按钮为圆形
* 15.简单的验证码
* 16.填写的验证码必须是数字的验证
* 17.设置窗体与背景图片一样大小
* 18.防止用户使用Alt+F4关闭窗体
* 19.运行后，无法拖放窗体,两种方法
*/ public partial
class 登录 : Form
{
public 登录()
{
InitializeComponent();
this.AcceptButton = button1;
//8 this.CancelButton = button3;
this.ShowInTaskbar =
false;
//9 this.MaximizeBox =
false;
//10 //this.WindowState = FormWindowState.Maximized;//11 this.StartPosition = FormStartPosition.CenterScreen;
//12 //this.FormBorderStyle = FormBorderStyle.FixedSingle;//19-1 //this.AutoSize = false;//19-2-1 //this.AutoSizeMode = AutoSizeMode.GrowAndShrink;//19-2-2 }
//登录判断 private void button1_Click(
object sender, EventArgs e)
{
if (textBox1.Text ==
"a")
{
if (textBox2.Text ==
"a"&&textBox4.Text==valid)
{
button4.Enabled =
true;
}
else {
MessageBox.Show(
"密码错误");
textBox2.Text =
string.Empty;
}
}
else {
if (textBox2.Text ==
"a")
{
MessageBox.Show(
"用户名错误");
textBox1.Text =
string.Empty;
}
else {
MessageBox.Show(
"用户名和密码错误");
textBox1.Text =
string.Empty;
textBox2.Text =
string.Empty;
textBox1.Focus();
}
}
}
//清空也可以使用string.Empty private void button2_Click(
object sender, EventArgs e)
{
textBox2.Text = "";
textBox1.Text = "";
}
//退出程序 private void button3_Click(
object sender, EventArgs e)
{
/*当本窗口是主线程窗口，以下三种方法均可以退出程序
*当本窗口不是主窗口时，如果要退出整个程序，应采用第3种方法，将一次性关闭程序上存在的所有线程。
*如果只是想关闭当前窗口而不退出程序，应采用第一种方法
*当本窗口不是主窗口时，采用第2种方法退出程序时，将会再执行关闭主窗体的步骤。
*/ //this.Close(); //Application.Exit(); Application.ExitThread();
}
//弹出新的窗体 private void button4_Click(
object sender, EventArgs e)
{
通讯录 f =
new 通讯录();
f.Show();
}
//3 private void textBox1_TextChanged(
object sender, EventArgs e)
{
if (textBox1.Text.Length > 4)
button1.Enabled =
false;
}
//3 private void button1_EnabledChanged(
object sender, EventArgs e)
{
if (!button1.Enabled)
label3.Text =
"请双击文本框重新登录！";
}
//4 private void textBox1_DoubleClick(
object sender, EventArgs e)
{
textBox1.Text = "";
label3.Visible =
false;
button1.Enabled =
true;
}
//5 private void textBox1_Leave(
object sender, EventArgs e)
{
if (textBox1.Text.Length > 6)
{
MessageBox.Show(
"用户名超过6位");
textBox1.Text = "";
textBox1.Focus();
}
//1 else if (textBox1.Text.Length == 0)
textBox1.BackColor = Color.Yellow;
}
private void 登录_Load(
object sender, EventArgs e)
{
//13 toolTip1.SetToolTip(textBox3,
"这里显示网址！");
//14 GraphicsPath path =
new GraphicsPath();
path.AddEllipse(
this.button1.ClientRectangle);
button1.Region =
new Region(path);
//产生验证码 GetValid();
label6.Font =
new Font (
"宋体",9,FontStyle.Italic);
label6.BackColor = Color.Transparent;
////17.设置窗体工作区的大小 //this.ClientSize = this.BackgroundImage.Size; CodeImage(GetcheckCode());
}
//2 private void textBox1_Enter(
object sender, EventArgs e)
{
//textBox1.BackColor = textBox2.BackColor; textBox1.BackColor = Color.FromKnownColor(KnownColor.Window);
}
//6 private void textBox1_KeyPress(
object sender, KeyPressEventArgs e)
{
if (e.KeyChar == 13)
textBox2.Focus();
}
//7 private void 登录_FormClosing(
object sender, FormClosingEventArgs e)
{
DialogResult jg = MessageBox.Show(
"你确定要关闭吗？",
"关闭登录窗体", MessageBoxButtons.YesNo, MessageBoxIcon.Information);
if (jg == DialogResult.No)
e.Cancel =
true;
}
private void button5_Click(
object sender, EventArgs e)
{
webBrowser1.Navigate(textBox3.Text.Trim());
}
//13 private void textBox2_MouseEnter(
object sender, EventArgs e)
{
toolTip2.Show(
"请输入密码！",
this);
}
//15产生4个验证码 string valid;
void GetValid()
{
Random rad =
new Random();
for (
int i = 0; i < 4; i++)
valid += rad.Next(0,9).ToString ();
label6.Text = valid;
}
//16.验证是数字的方法 bool IsNum(
string s)
{
//1.使用异常检测的方法 //try //{ // Convert .ToInt32(s); //} //catch //{ // return false ; //} //return true ; ////2.使用正则表达式 //string regex = @"^\d+(\.\d)?$"; //if (!Regex.IsMatch(s, regex)) // return false; //else // return true; //3.调用VB的information的方法，判断是否为数字。先添加Microsoft.VisualBasic引用 return Microsoft.VisualBasic.Information.IsNumeric(s);
}
//16 private void textBox4_Leave(
object sender, EventArgs e)
{
if (!IsNum(textBox4.Text)||textBox4.Text .Trim ().Length!=4)
{
textBox4.Text = "";
MessageBox.Show(
"请输入正确的数字格式！");
}
}
//18 private void 登录_KeyDown(
object sender, KeyEventArgs e)
{
if (e.KeyCode == Keys.F4 && e.Modifiers == Keys.Alt)
e.Handled =
true;
}
//产生随机数 string GetcheckCode()
{
int number;
char code;
string checkcode = "";
Random rdm =
new Random();
for (
int i = 0; i < 4; i++)
{
number = rdm.Next();
//number = rdm.Next(0,9); if (number % 2 == 0)
code = (
char)('0' + (
char)(number % 10));
else code = (
char)('A' + (
char)(number % 26));
checkcode +="" +code.ToString ();
}
return checkcode;
}
void CodeImage(
string code)
{
if (code ==
null || code.Trim() ==
string.Empty)
return;
System.Drawing.Bitmap image =
new System.Drawing.Bitmap((
int)Math.Ceiling (code.Length*10.0),22);
Graphics g = Graphics.FromImage(image);
try {
Random rdm =
new Random();
g.Clear(Color.White);
//画图片的背景噪音线 for (
int i = 0; i < 3; i++)
{
int x1 = rdm.Next(image.Width);
int x2 = rdm.Next(image.Width);
int y1 = rdm.Next(image.Height);
int y2 = rdm.Next(image.Height);
g.DrawLine(
new Pen(Color.Black), x1, y1, x2, y2);
}
Font font =
new System.Drawing.Font(
"Arial", 12, FontStyle.Bold);
g.DrawString(code, font,
new SolidBrush(Color.Red), 2, 2);
//画前景噪音线 for (
int i = 0; i < 150; i++)
{
int x = rdm.Next(image.Width);
int y = rdm.Next(image.Height);
image.SetPixel(x, y, Color.FromArgb(rdm.Next()));
}
g.DrawRectangle(
new Pen(Color.Silver), 0, 0, image.Width - 1, image.Height - 1);
pictureBox1.Width = image.Width;
pictureBox1.Height = image.Height;
pictureBox1.Image = image;
}
catch { }
}
}
}
