C# WinForm 登入介面的圖片驗證碼(區分大小寫+不區分大小寫)
阿新 • • 發佈：2020-02-18
一、功能介面
圖1 驗證碼(區分大小寫)
二、建立一個產生驗證碼的類Class1
（1）生成隨機驗證碼字串，用的是Random隨機函式
（2）建立驗證碼圖片，將該字串畫在PictureBox控制元件中
Class1.cs：
using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Threading.Tasks;
using System.Drawing;//圖片
using System.Windows.Forms;
namespace ValidCodeTest
{
public class Class1
{
#region 驗證碼功能
/// <summary>
/// 生成隨機驗證碼字串
/// </summary>
public static string CreateRandomCode(int CodeLength)
{
int rand;
char code;
string randomCode = String.Empty;//隨機驗證碼
//生成一定長度的隨機驗證碼
//Random random = new Random();//生成隨機數物件
for (int i = 0; i < CodeLength; i++)
{
//利用GUID生成6位隨機數
byte[] buffer = Guid.NewGuid().ToByteArray();//生成位元組陣列
int seed = BitConverter.ToInt32(buffer,0);//利用BitConvert方法把位元組陣列轉換為整數
Random random = new Random(seed);//以生成的整數作為隨機種子
rand = random.Next();
//rand = random.Next();
if (rand % 3 == 1)
{
code = (char)('A' + (char)(rand % 26));
}
else if (rand % 3 == 2)
{
code = (char)('a' + (char)(rand % 26));
}
else
{
code = (char)('0' + (char)(rand % 10));
}
randomCode += code.ToString();
}
return randomCode;
}
/// <summary>
/// 建立驗證碼圖片
/// </summary>
public static void CreateImage(string strValidCode,PictureBox pbox)
{
try
{
int RandAngle = 45;//隨機轉動角度
int MapWidth = (int)(strValidCode.Length * 21);
Bitmap map = new Bitmap(MapWidth,28);//驗證碼圖片—長和寬
//建立繪圖物件Graphics
Graphics graph = Graphics.FromImage(map);
graph.Clear(Color.AliceBlue);//清除繪畫面,填充背景色
graph.DrawRectangle(new Pen(Color.Black,0),map.Width - 1,map.Height - 1);//畫一個邊框
graph.SmoothingMode = System.Drawing.Drawing2D.SmoothingMode.AntiAlias;//模式
Random rand = new Random();
//背景噪點生成
Pen blackPen = new Pen(Color.LightGray,0);
for (int i = 0; i < 50; i++)
{
int x = rand.Next(0,map.Width);
int y = rand.Next(0,map.Height);
graph.DrawRectangle(blackPen,x,y,1,1);
}
//驗證碼旋轉，防止機器識別
char[] chars = strValidCode.ToCharArray();//拆散字串成單字元陣列
//文字居中
StringFormat format = new StringFormat(StringFormatFlags.NoClip);
format.Alignment = StringAlignment.Center;
format.LineAlignment = StringAlignment.Center;
//定義顏色
Color[] c = { Color.Black,Color.Red,Color.DarkBlue,Color.Green,Color.Orange,Color.Brown,Color.DarkCyan,Color.Purple };
//定義字型
string[] font = { "Verdana","Microsoft Sans Serif","Comic Sans MS","Arial","宋體" };
for (int i = 0; i < chars.Length; i++)
{
int cindex = rand.Next(7);
int findex = rand.Next(5);
Font f = new System.Drawing.Font(font[findex],13,System.Drawing.FontStyle.Bold);//字型樣式(引數2為字型大小)
Brush b = new System.Drawing.SolidBrush(c[cindex]);
Point dot = new Point(16,16);
float angle = rand.Next(-RandAngle,RandAngle);//轉動的度數
graph.TranslateTransform(dot.X,dot.Y);//移動游標到指定位置
graph.RotateTransform(angle);
graph.DrawString(chars[i].ToString(),f,b,format);
graph.RotateTransform(-angle);//轉回去
graph.TranslateTransform(2,-dot.Y);//移動游標到指定位置
}
pbox.Image = map;
}
catch (ArgumentException)
{
MessageBox.Show("驗證碼圖片建立錯誤");
}
}
#endregion
}
}三、呼叫
（1）更新驗證碼
（2）驗證（區分大小寫）
（3）驗證（不區分大小寫）
Form1.cs：
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;
using ValidCodeTest;
namespace ValidCode
{
public partial class Form1 : Form
{
public Form1()
{
InitializeComponent();
}
#region 驗證碼
private const int ValidCodeLength = 4;//驗證碼長度
private String strValidCode = "";//驗證碼
//呼叫自定義函式,更新驗證碼
private void UpdateValidCode()
{
strValidCode = Class1.CreateRandomCode(ValidCodeLength);//生成隨機驗證碼
if (strValidCode == "") return;
Class1.CreateImage(strValidCode,pbox1);//建立驗證碼圖片
}
#endregion
private void pbox1_Click(object sender,EventArgs e)
{
UpdateValidCode();//點選更新驗證碼
}
private void Form1_Load(object sender,EventArgs e)
{
UpdateValidCode();//載入更新驗證碼
}
/// <summary>
/// 驗證（區分大小寫）
/// </summary>
private void btn1_Click(object sender,EventArgs e)
{
string validcode = txtValidCode.Text.Trim();
char[] ch1 = validcode.ToCharArray();
char[] ch2 = strValidCode.ToCharArray();
int Count1 = 0;//字母個數
int Count2 = 0;//數字個數
if (String.IsNullOrEmpty(validcode) != true)//驗證碼不為空
{
for (int i = 0; i < strValidCode.Length; i++)
{
if ((ch1[i] >= 'a' && ch1[i] <= 'z') || (ch1[i] >= 'A' && ch1[i] <= 'Z'))//字母
{
if (ch1[i] == ch2[i])
{
Count1++;
}
}
else//數字
{
if (ch1[i] == ch2[i])
{
Count2++;
}
}
}
int CountSum = Count1 + Count2;
if (CountSum == strValidCode.Length)
{
MessageBox.Show("驗證通過","提示",MessageBoxButtons.OK,MessageBoxIcon.Information);
UpdateValidCode();
txtValidCode.Text = "";
txtValidCode.Focus();
}
else
{
MessageBox.Show("驗證失敗","警告",MessageBoxIcon.Exclamation);
UpdateValidCode();//更新驗證碼
txtValidCode.Text = "";
txtValidCode.Focus();
}
}
else//驗證碼為空
{
MessageBox.Show("請輸入驗證碼",MessageBoxIcon.Information);
UpdateValidCode();//更新驗證碼
txtValidCode.Text = "";
txtValidCode.Focus();
}
}
/// <summary>
/// 驗證（不區分大小寫）
/// </summary>
private void btn2_Click(object sender,EventArgs e)
{
string validcode = txtValidCode.Text.Trim();
if (String.IsNullOrEmpty(validcode) != true)//驗證碼不為空
{
if (validcode.ToLower() == strValidCode.ToLower())
{
MessageBox.Show("驗證通過",MessageBoxIcon.Information);
UpdateValidCode();//更新驗證碼
txtValidCode.Text = "";
txtValidCode.Focus();
}
}
}
}.exe測試檔案下載: ValidCode_jb51.zip
參考文章：
https://www.jianshu.com/p/d89f22cf51bf
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