戏说 .NET GDI+系列学习教程(三、Graphics类的应用_验证码)
2024-05-06 14:24:54
关于Graphics也有了基本了解下面想说的的是学这个东东干什么呢，到底如何应用
目前常见应用
1、验证码（参照网上的）
2、打印排版（会提到关于条形码大小设置）
3、自定义控件
一、验证码
1 class ValidateCode
2 {
3 #region 定义和初始化配置字段
4
5 //用户存取验证码字符串
6 public string validationCode = String.Empty;
7
8 //生成的验证码字符串
9 public char[] chars = null;
10
11 /// <summary>
12 /// 获取随机验证码
13 /// </summary>
14 public String ValidationCode
15 {
16 get { return validationCode; }
17 }
18
19 /// <summary>
20 /// 验证码字符串的长度
21 /// </summary>
22 private Int32 validationCodeCount = 4;
23
24 /// <summary>
25 /// 获取和设置验证码字符串的长度
26 /// </summary>
27 public Int32 ValidationCodeCount
28 {
29 get { return validationCodeCount; }
30 set { validationCodeCount = value; }
31 }
32
33 /// <summary>
34 /// 画板对象
35 /// </summary>
36 Graphics dc = null;
37
38 //验证码的宽度，默认为130
39 private int bgWidth = 130;
40
41 /// <summary>
42 /// 验证码的宽度，默认为130
43 /// </summary>
44 public Int32 Width
45 {
46 get { return bgWidth; }
47 set { bgWidth = value; }
48 }
49
50 //验证码的宽度，默认为130
51 private int bgHeight = 40;
52
53 /// <summary>
54 /// 验证码的高度，默认为40
55 /// </summary>
56 public Int32 Height
57 {
58 get { return bgHeight; }
59 set { bgHeight = value; }
60 }
61
62 //字体大小 字体最小值
63 private int fontMinSize = 20;
64
65 /// <summary>
66 /// 验证码字体的最小值，默认为20,建议不小于15像素
67 /// </summary>
68 public Int32 FontMinSize
69 {
70 get { return fontMinSize; }
71 set { fontMinSize = value; }
72 }
73 //字体大小 字体最大值
74 private Int32 fontMaxSize = 25;
75
76 /// <summary>
77 /// 验证码字体的最大值，默认为25
78 /// </summary>
79 public Int32 FontMaxSize
80 {
81 get { return fontMaxSize; }
82 set { fontMaxSize = value; }
83 }
84
85 //验证码字体的颜色
86 private Color[] fontColor = { };
87
88 /// <summary>
89 /// 验证码字体的颜色，默认为系统自动生成字体颜色
90 /// </summary>
91 public Color[] FontColor
92 {
93 get { return fontColor; }
94 set { fontColor = value; }
95 }
96
97 private Color backColor = Color.FromArgb(243, 255, 255);
98
99 /// <summary>
100 /// 验证码的背景色，默认为Color.FromArgb(243, 251, 254)
101 /// </summary>
102 public Color BackgroundColor
103 {
104 get { return backColor; }
105 set { backColor = value; }
106 }
107
108 //贝塞尔曲线的条数,默认为3条
109 private Int32 bezierCount = 3;
110
111 /// <summary>
112 /// 贝塞尔曲线的条数,默认为3条
113 /// </summary>
114 public Int32 BezierCount
115 {
116 get { return bezierCount; }
117 set { bezierCount = value; }
118 }
119
120 //直线条数，默认为3条
121 private Int32 lineCount = 3;
122
123 /// <summary>
124 /// 直线条数，默认为3条
125 /// </summary>
126 public Int32 LineCount
127 {
128 get { return lineCount; }
129 set { lineCount = value; }
130 }
131
132 //随机字符串列表
133 private String charCollection = "2,3,4,5,6,7,8,9,a,s,d,f,g,h,z,c,v,b,n,m,k,q,w,e,r,t,y,u,p,A,S,D,F,G,H,Z,C,V,B,N,M,K,Q,W,E,R,T,Y,U,P"; //定义验证码字符及出现频次 ,避免出现0 o j i l 1 x;
134
135 /// <summary>
136 /// 随机字符串列表，请使用英文状态下的逗号分隔
137 /// </summary>
138 public String CharCollection
139 {
140 get { return charCollection; }
141 set { charCollection = value; }
142 }
143
144 //验证码字符串个数，默认为4个字符
145 private Int32 intCount = 4;
146
147 /// <summary>
148 /// 验证码字符串个数，默认为4个字符
149 /// </summary>
150 public Int32 IntCount
151 {
152 get { return intCount; }
153 set { intCount = value; }
154 }
155
156 //是否添加噪点，默认添加，噪点颜色为系统随机生成。
157 private Boolean isPixel = true;
158 /// <summary>
159 /// 是否添加噪点，默认添加，噪点颜色为系统随机生成。
160 /// </summary>
161 public Boolean IsPixel
162 {
163 get { return isPixel; }
164 set { isPixel = value; }
165 }
166
167 //是否添加随机噪点字符串，默认添加
168 private Boolean isRandString = true;
169 /// <summary>
170 /// 是否添加随机噪点字符串，默认添加
171 /// </summary>
172 public Boolean IsRandString
173 {
174 get { return isRandString; }
175 set { isRandString = value; }
176 }
177
178 /// <summary>
179 /// 随机背景字符串的个数
180 /// </summary>
181 public Int32 RandomStringCount
182 {
183 get; set;
184 }
185
186 //随机背景字符串的大小
187 private Int32 randomStringFontSize = 9;
188 /// <summary>
189 /// 随机背景字符串的大小
190 /// </summary>
191 public Int32 RandomStringFontSize
192 {
193 get { return randomStringFontSize; }
194 set { randomStringFontSize = value; }
195 }
196
197 /// <summary>
198 /// 是否对图片进行扭曲
199 /// </summary>
200 public Boolean IsTwist
201 {
202 get; set;
203 }
204
205 /// <summary>
206 /// 边框样式
207 /// </summary>
208 public enum BorderStyle
209 {
210 /// <summary>
211 /// 无边框
212 /// </summary>
213 None,
214 /// <summary>
215 /// 矩形边框
216 /// </summary>
217 Rectangle,
218 /// <summary>
219 /// 圆角边框
220 /// </summary>
221 RoundRectangle
222 }
223
224 /// <summary>
225 /// 验证码字符串随机转动的角度 默认40
226 /// </summary>
227 private Int32 rotationAngle = 40;
228 /// <summary>
229 /// 验证码字符串随机转动的角度的最大值
230 /// </summary>
231 public Int32 RotationAngle
232 {
233 get { return rotationAngle; }
234 set { rotationAngle = value; }
235 }
236
237 /// <summary>
238 /// 设置或获取边框样式
239 /// </summary>
240 public BorderStyle Border
241 {
242 get; set;
243 }
244
245 /// <summary>
246 /// 对验证码图片进行高斯模糊的阀值，如果设置为0
247 /// </summary>
248 private Double gaussianDeviation = 0;
249
250 /// <summary>
251 /// 对验证码图片进行高斯模糊的阀值，如果设置为0，则不对图片进行高斯模糊，该设置可能会对图片处理的性能有较大影响
252 /// </summary>
253 public Double GaussianDeviation
254 {
255 get { return gaussianDeviation; }
256 set { gaussianDeviation = value; }
257 }
258 private Int32 brightnessValue = 0;
259 /// <summary>
260 /// 对图片进行暗度和亮度的调整，如果该值为0，则不调整。该设置会对图片处理性能有较大影响
261 /// </summary>
262 public Int32 BrightnessValue
263 {
264 get { return brightnessValue; }
265 set { brightnessValue = value; }
266 }
267
268 #endregion
269
270
271 private Point[] strPoint = null;
272
273 Random random = new Random();
274
275 /// <summary>
276 /// 构造函数，用于初始化常用变量
277 /// </summary>
278 public void DrawValidationCode()
279 {
280 //随机对象
281 //Random类所取到的系统时钟种子接近甚至完全一样
282 //解决方案：new Random(Guid.NewGuid().GetHashCode());
283 random = new Random(Guid.NewGuid().GetHashCode());
284 //坐标数组
285 strPoint = new Point[validationCodeCount + 1];
286 if (gaussianDeviation < 0)
287 gaussianDeviation = 0;
288 }
289
290 /// <summary>
291 /// 生成验证码
292 /// 思路：多张图片合成
293 /// 1.验证码背景图片
294 /// 1.1.背景包含
295 /// 1.1.1.背景颜色
296 /// 1.1.2.噪点
297 /// 1.1.3.干扰文字
298 /// 1.1.4.干扰线条（直线、曲线）
299 /// 2.验证码字符
300 /// 3.验证码图片扭曲
301 /// 4.验证码图片模糊
302 /// 5.验证码图片亮度
303 /// 6.验证码图片保持在内存流中
304 /// </summary>
305 /// <param name="target">用于存储图片的一般字节序列</param>
306 public MemoryStream CreateImage(string code)
307 {
308 MemoryStream target = new MemoryStream();
309 // 定义图片对象大小，
310 Bitmap bit = new Bitmap(bgWidth + 1, bgHeight + 1);
311 // 定义 Graphics（画板）根据图片对象
312 dc = Graphics.FromImage(bit);
313 /*
314 SmoothingModeAntiAlias 指定消除锯齿的呈现。
315 SmoothingModeDefault 指定默认模式。
316 SmoothingModeHighQuality 指定高质量、低速度呈现。
317 SmoothingModeHighSpeed 指定高速度、低质量呈现。
318 SmoothingModeInvalid 指定一个无效模式。
319 SmoothingModeNone 指定不消除锯齿。
320 */
321 dc.SmoothingMode = SmoothingMode.HighQuality;
322 //文本的呈现模式
323 dc.TextRenderingHint = TextRenderingHint.ClearTypeGridFit;
324 // 插补模式
325 dc.InterpolationMode = InterpolationMode.HighQualityBilinear;
326 //合成图像的呈现质量
327 dc.CompositingQuality = CompositingQuality.HighQuality;
328 try
329 {
330 //清空画板，指定背景色（白色）
331 dc.Clear(Color.White);
332 DrawValidationCode();
333 //DrawImageUnscaled 在指定的位置使用图像的原始物理大小绘制指定的图像
334 // 验证码背景
335 dc.DrawImageUnscaled(DrawBackground(), 0, 0);
336 // 验证码字符
337 dc.DrawImageUnscaled(DrawRandomString(code), 0, 0);
338 //对图片文字进行扭曲
339 bit = AdjustRippleEffect(bit, 5);
340 //对图片进行高斯模糊
341 if (gaussianDeviation > 0)
342 {
343 Gaussian gau = new Gaussian();
344 bit = gau.FilterProcessImage(gaussianDeviation, bit);
345 }
346 //进行暗度和亮度处理
347 if (brightnessValue != 0)
348 {
349 //对图片进行调暗处理
350 bit = AdjustBrightness(bit, brightnessValue);
351 }
352 bit.Save(target, ImageFormat.Jpeg);
353 //输出图片流
354 return target;
355
356 }
357 finally
358 {
359 //brush.Dispose();
360 bit.Dispose();
361 dc.Dispose();
362 }
363 }
364
365 #region 画验证码背景，例如，增加早点，添加曲线和直线等
366 /// <summary>
367 /// 画验证码背景，例如，增加早点，添加曲线和直线等
368 /// 1.1.背景包含
369 /// 1.1.1.背景颜色
370 /// 1.1.2.噪点
371 /// 1.1.3.干扰文字
372 /// 1.1.4.干扰线条（直线、曲线）
373 /// </summary>
374 /// <returns>Bitmap 对象</returns>
375 private Bitmap DrawBackground()
376 {
377 Bitmap bit = new Bitmap(bgWidth + 1, bgHeight + 1);
378 Graphics g = Graphics.FromImage(bit);
379 g.SmoothingMode = SmoothingMode.HighQuality;
380 g.Clear(Color.White);
381 Rectangle rectangle = new Rectangle(0, 0, bgWidth, bgHeight);
382 Brush brush = new SolidBrush(backColor);
383 //填充矩形
384 g.FillRectangle(brush, rectangle);
385 //画噪点
386 if (isPixel)
387 {
388 g.DrawImageUnscaled(DrawRandomPixel(30), 0, 0);
389 }
390 // 背景干扰字符
391 g.DrawImageUnscaled(DrawRandBgString(), 0, 0);
392 //画曲线
393 //g.DrawImageUnscaled(DrawRandomBezier(bezierCount), 0, 0);
394 //画直线
395 //g.DrawImageUnscaled(DrawRandomLine(lineCount), 0, 0);
396 if (Border == BorderStyle.Rectangle)
397 {
398 //绘制边框
399 g.DrawRectangle(new Pen(Color.FromArgb(90, 87, 46)), 0, 0, bgWidth, bgHeight);
400 }
401 else if (Border == BorderStyle.RoundRectangle)
402 {
403 //画圆角
404 DrawRoundRectangle(g, rectangle, Color.FromArgb(90, 87, 46), 1, 3);
405 }
406 return bit;
407 }
408 #endregion
409
410 #region 画随机噪点
411 /// <summary>
412 /// 画随机噪点
413 /// 在指定区域中随机设置像素点的颜色
414 /// </summary>
415 /// <param name="pixNum">噪点的百分比</param>
416 /// <returns></returns>
417 public Bitmap DrawRandomPixel(Int32 pixNum)
418 {
419 Bitmap b = new Bitmap(bgWidth, bgHeight);
420 //透明化
421 b.MakeTransparent();
422 Graphics graph = Graphics.FromImage(b);
423 graph.SmoothingMode = SmoothingMode.HighQuality;
424 graph.InterpolationMode = InterpolationMode.HighQualityBilinear;
425 //画噪点
426 for (int i = 0; i < (bgHeight * bgWidth) / pixNum; i++)
427 {
428 int x = random.Next(b.Width);
429 int y = random.Next(b.Height);
430 //设置随机像素点的颜色
431 b.SetPixel(x, y, GetRandomDeepColor());
432 //下移坐标重新画点
433 if ((x + 1) < b.Width && (y + 1) < b.Height)
434 {
435 //画图片的前景噪音点
436 graph.DrawRectangle(new Pen(Color.Silver), random.Next(b.Width), random.Next(b.Height), 1, 1);
437 }
438 }
439 return b;
440 }
441 #endregion
442
443 #region 画干扰背景文字
444 /// <summary>
445 /// 画背景干扰文字
446 /// </summary>
447 /// <returns></returns>
448 private Bitmap DrawRandBgString()
449 {
450 Bitmap b = new Bitmap(bgWidth, bgHeight);
451 String[] randStr = { "a", "b", "c", "d", "e", "f", "g", "h", "i", "j", "k", "l", "m", "n", "o", "p", "q", "r", "s", "t", "u", "v", "w", "x", "y", "z", "A", "B", "C", "D", "E", "F", "G", "H", "I", "J", "K", "L", "M", "N", "O", "P", "Q", "R", "S", "T", "U", "V", "W", "X", "Y", "Z" };
452 //设置透明
453 b.MakeTransparent();
454 Graphics g = Graphics.FromImage(b);
455 g.Clear(Color.Transparent);
456 g.PixelOffsetMode = PixelOffsetMode.HighQuality;
457 g.SmoothingMode = SmoothingMode.HighQuality;
458 g.TextRenderingHint = TextRenderingHint.AntiAlias;
459 g.InterpolationMode = InterpolationMode.HighQualityBilinear;
460 //设置字体显示格式
461 StringFormat format = new StringFormat(StringFormatFlags.NoClip);
462 format.Alignment = StringAlignment.Center;
463 format.LineAlignment = StringAlignment.Center;
464 FontFamily f = new FontFamily(GenericFontFamilies.Serif);
465 Font textFont = new Font(f, randomStringFontSize, FontStyle.Underline);
466 int randAngle = 60; //随机转动角度
467 for (int i = 0; i < RandomStringCount; i++)
468 {
469 Brush brush = new System.Drawing.SolidBrush(GetRandomLightColor());
470 Point pot = new Point(random.Next(5, bgWidth - 5), random.Next(5, bgHeight - 5));
471 //随机转动的度数
472 float angle = random.Next(-randAngle, randAngle);
473 //转动画布
474 g.RotateTransform(angle);
475 g.DrawString(randStr[random.Next(randStr.Length)], textFont, brush, pot, format);
476 //转回去，为下一个字符做准备
477 g.RotateTransform(-angle);
478 //释放资源
479 brush.Dispose();
480 }
481 textFont.Dispose();
482 format.Dispose();
483 f.Dispose();
484 return b;
485 }
486 #endregion
487
488 #region 随机生成贝塞尔曲线
489 /// <summary>
490 /// 随机生成贝塞尔曲线
491 /// </summary>
492 /// <param name="bmp">一个图片的实例</param>
493 /// <param name="lineNum">线条数量</param>
494 /// <returns></returns>
495 public Bitmap DrawRandomBezier(Int32 lineNum)
496 {
497 Bitmap b = new Bitmap(bgWidth, bgHeight);
498 b.MakeTransparent();
499 Graphics g = Graphics.FromImage(b);
500 g.Clear(Color.Transparent);
501 g.SmoothingMode = SmoothingMode.HighQuality;
502 g.PixelOffsetMode = PixelOffsetMode.HighQuality;
503 GraphicsPath gPath1 = new GraphicsPath();
504 Int32 lineRandNum = random.Next(lineNum);
505 for (int i = 0; i < (lineNum - lineRandNum); i++)
506 {
507 Pen p = new Pen(GetRandomDeepColor());
508 Point[] point = {
509 new Point(random.Next(1, (b.Width / 10)), random.Next(1, (b.Height))),
510 new Point(random.Next((b.Width / 10) * 2, (b.Width / 10) * 4), random.Next(1, (b.Height))),
511 new Point(random.Next((b.Width / 10) * 4, (b.Width / 10) * 6), random.Next(1, (b.Height))),
512 new Point(random.Next((b.Width / 10) * 8, b.Width), random.Next(1, (b.Height)))
513 };
514 gPath1.AddBeziers(point);
515 g.DrawPath(p, gPath1);
516 p.Dispose();
517 }
518 for (int i = 0; i < lineRandNum; i++)
519 {
520 Pen p = new Pen(GetRandomDeepColor());
521 Point[] point = {
522 new Point(random.Next(1, b.Width), random.Next(1, b.Height)),
523 new Point(random.Next((b.Width / 10) * 2, b.Width), random.Next(1, b.Height)),
524 new Point(random.Next((b.Width / 10) * 4, b.Width), random.Next(1, b.Height)),
525 new Point(random.Next(1, b.Width), random.Next(1, b.Height))
526 };
527 gPath1.AddBeziers(point);
528 g.DrawPath(p, gPath1);
529 p.Dispose();
530 }
531 return b;
532 }
533 #endregion
534
535 #region 画直线
536 /// <summary>
537 /// 画直线
538 /// </summary>
539 /// <param name="bmp">一个bmp实例</param>
540 /// <param name="lineNum">线条个数</param>
541 /// <returns></returns>
542 public Bitmap DrawRandomLine(Int32 lineNum)
543 {
544 if (lineNum < 0) throw new ArgumentNullException("参数bmp为空！");
545 Bitmap b = new Bitmap(bgWidth, bgHeight);
546 b.MakeTransparent();
547 Graphics g = Graphics.FromImage(b);
548 g.Clear(Color.Transparent);
549 g.PixelOffsetMode = PixelOffsetMode.HighQuality;
550 g.SmoothingMode = SmoothingMode.HighQuality;
551 for (int i = 0; i < lineNum; i++)
552 {
553 Pen p = new Pen(GetRandomDeepColor());
554 Point pt1 = new Point(random.Next(1, (b.Width / 5) * 2), random.Next(b.Height));
555 Point pt2 = new Point(random.Next((b.Width / 5) * 3, b.Width), random.Next(b.Height));
556 g.DrawLine(p, pt1, pt2);
557 p.Dispose();
558 }
559 return b;
560 }
561 #endregion
562
563 #region 写入验证码的字符串
564 /// <summary>
565 /// 写入验证码的字符串
566 /// </summary>
567 private Bitmap DrawRandomString(string Code)
568 {
569 if (fontMaxSize >= (bgHeight / 5) * 4)
570 throw new ArgumentException("字体最大值参数FontMaxSize与验证码高度相近，这会导致描绘验证码字符串时出错，请重新设置参数！");
571 Bitmap b = new Bitmap(bgWidth, bgHeight);
572 b.MakeTransparent();
573 Graphics g = Graphics.FromImage(b);
574 g.Clear(Color.Transparent);
575 g.PixelOffsetMode = PixelOffsetMode.Half;
576 g.SmoothingMode = SmoothingMode.HighQuality;
577 g.TextRenderingHint = TextRenderingHint.SingleBitPerPixelGridFit;
578 g.InterpolationMode = InterpolationMode.HighQualityBilinear;
579 chars = Code.ToCharArray(); //拆散字符串成单字符数组
580 validationCode = chars.ToString();
581 //设置字体显示格式
582 StringFormat format = new StringFormat(StringFormatFlags.NoClip);
583 format.Alignment = StringAlignment.Center;
584 format.LineAlignment = StringAlignment.Center;
585 FontFamily f = new FontFamily(GenericFontFamilies.Monospace);
586 Int32 charNum = chars.Length;
587 Point sPoint = new Point();
588 Int32 fontSize = 12;
589 validationCodeCount = charNum;
590 for (int i = 0; i < validationCodeCount; i++)
591 {
592 //定义字体
593 Font textFont = new Font(f, random.Next(fontMinSize, fontMaxSize), FontStyle.Bold);
594 //定义画刷，用于写字符串
595 //Brush brush = new SolidBrush(GetRandomDeepColor());
596 Int32 textFontSize = Convert.ToInt32(textFont.Size);
597 fontSize = textFontSize;
598 //Point point = new Point(random.Next((bgWidth / charNum) * i + 5, (bgWidth / charNum) * (i + 1)), random.Next(bgHeight / 5 + textFontSize / 2, bgHeight - textFontSize / 2));
599 // 字符位置坐标
600 Point point = new Point(random.Next((bgWidth / charNum) * i + 2, (bgWidth / charNum) * (i + 1) - (textFontSize / 2)), random.Next(bgHeight / 5 + textFontSize / 2, bgHeight - textFontSize / 2));
601 //如果当前字符X坐标小于字体的二分之一大小
602 if (point.X < textFontSize / 2)
603 {
604 point.X = point.X + textFontSize / 2;
605 }
606 //防止文字叠加
607 if (i > 0 && (point.X - sPoint.X < (textFontSize / 2 + textFontSize / 2)))
608 {
609 point.X = point.X + textFontSize;
610 }
611 //如果当前字符X坐标大于图片宽度，就减去字体的宽度
612 if (point.X > (bgWidth - textFontSize / 2))
613 {
614 point.X = bgWidth - textFontSize / 2;
615 }
616 sPoint = point;
617 float angle = random.Next(-rotationAngle, rotationAngle);//转动的度数
618 g.TranslateTransform(point.X, point.Y);
619 g.RotateTransform(angle);
620
621 Rectangle myretang = new Rectangle(0, 1, Convert.ToInt32(textFont.Size), Convert.ToInt32(textFont.Size));
622 Color c = GetRandomDeepColor();
623 //设置渐变画刷
624 LinearGradientBrush mybrush2 = new LinearGradientBrush(myretang, c, GetLightColor(c, 120), random.Next(180));
625 g.DrawString(chars[i].ToString(), textFont, mybrush2, 1, 1, format);
626
627 g.RotateTransform(-angle);//转回去
628 g.TranslateTransform(-point.X, -point.Y);//移动光标到指定位置，每个字符紧凑显示，避免被软件识别
629 strPoint[i] = point;
630 textFont.Dispose();
631 mybrush2.Dispose();
632 }
633 return b;
634 }
635 #endregion
636
637 #region 增加或減少亮度
638 /// <summary>
639 /// 增加或減少亮度
640 /// </summary>
641 /// <param name="img">System.Drawing.Image Source </param>
642 /// <param name="valBrightness">0~255</param>
643 /// <returns></returns>
644 public System.Drawing.Bitmap AdjustBrightness(System.Drawing.Image img, int valBrightness)
645 {
646 // 讀入欲轉換的圖片並轉成為 Bitmap
647 System.Drawing.Bitmap bitmap = new System.Drawing.Bitmap(img);
648 for (int y = 0; y < bitmap.Height; y++)
649 {
650 for (int x = 0; x < bitmap.Width; x++)
651 {
652 // 取得每一個 pixel
653 var pixel = bitmap.GetPixel(x, y);
654 // 判斷 如果處理過後 255 就設定為 255 如果小於則設定為 0
655 var pR = ((pixel.R + valBrightness > 255) ? 255 : pixel.R + valBrightness) < 0 ? 0 : ((pixel.R + valBrightness > 255) ? 255 : pixel.R + valBrightness);
656 var pG = ((pixel.G + valBrightness > 255) ? 255 : pixel.G + valBrightness) < 0 ? 0 : ((pixel.G + valBrightness > 255) ? 255 : pixel.G + valBrightness);
657 var pB = ((pixel.B + valBrightness > 255) ? 255 : pixel.B + valBrightness) < 0 ? 0 : ((pixel.B + valBrightness > 255) ? 255 : pixel.B + valBrightness);
658 // 將改過的 RGB 寫回
659 System.Drawing.Color newColor = System.Drawing.Color.FromArgb(pixel.A, pR, pG, pB);
660 bitmap.SetPixel(x, y, newColor);
661 }
662 }
663 // 回傳結果
664 return bitmap;
665 }
666 #endregion
667
668 #region 水波纹效果
669 /// <summary>
670 /// 水波纹效果
671 /// </summary>
672 /// <param name="src"></param>
673 /// <param name="nWave">坡度</param>
674 /// www.it165.net
675 /// <returns></returns>
676 public Bitmap AdjustRippleEffect(Bitmap src, short nWave)
677 {
678 int nWidth = src.Width;
679 int nHeight = src.Height;
680 // 透过公式进行水波纹的採样
681 PointF[,] fp = new PointF[nWidth, nHeight];
682 Point[,] pt = new Point[nWidth, nHeight];
683 Point mid = new Point();
684 mid.X = nWidth / 2;
685 mid.Y = nHeight / 2;
686 double newX, newY;
687 double xo, yo;
688 //先取样将水波纹座标跟RGB取出
689 for (int x = 0; x < nWidth; ++x)
690 for (int y = 0; y < nHeight; ++y)
691 {
692 xo = ((double)nWave * Math.Sin(2.0 * 3.1415 * (float)y / 128.0));
693 yo = ((double)nWave * Math.Cos(2.0 * 3.1415 * (float)x / 128.0));
694 newX = (x + xo);
695 newY = (y + yo);
696 if (newX > 0 && newX < nWidth)
697 {
698 fp[x, y].X = (float)newX;
699 pt[x, y].X = (int)newX;
700 }
701 else
702 {
703 fp[x, y].X = (float)0.0;
704 pt[x, y].X = 0;
705 }
706 if (newY > 0 && newY < nHeight)
707 {
708 fp[x, y].Y = (float)newY;
709 pt[x, y].Y = (int)newY;
710 }
711 else
712 {
713 fp[x, y].Y = (float)0.0;
714 pt[x, y].Y = 0;
715 }
716 }
717 //进行合成
718 Bitmap bSrc = (Bitmap)src.Clone();
719 // 依照 Format24bppRgb 每三个表示一 Pixel 0: 蓝 1: 绿 2: 红
720 BitmapData bitmapData = src.LockBits(new Rectangle(0, 0, src.Width, src.Height), ImageLockMode.ReadWrite, PixelFormat.Format24bppRgb);
721 BitmapData bmSrc = bSrc.LockBits(new Rectangle(0, 0, bSrc.Width, bSrc.Height), ImageLockMode.ReadWrite, PixelFormat.Format24bppRgb);
722 int scanline = bitmapData.Stride;
723 IntPtr Scan0 = bitmapData.Scan0;
724 IntPtr SrcScan0 = bmSrc.Scan0;
725 //指针在c#中是不提倡使用的，有关指针的操作被认为是不安全的(unsafe)。因此运行这段代码之前，先要改一个地方，否则编译不过无法运行。
726 //修改方法：找到你的项目，在项目图标上点右键，选项目属性（Properties）,Build标签页里把Allow unsafe code勾选上
727 unsafe
728 {
729 //指针
730 byte* p = (byte*)(void*)Scan0;
731 byte* pSrc = (byte*)(void*)SrcScan0;
732 int nOffset = bitmapData.Stride - src.Width * 3;
733 int xOffset, yOffset;
734 for (int y = 0; y < nHeight; ++y)
735 {
736 for (int x = 0; x < nWidth; ++x)
737 {
738 xOffset = pt[x, y].X;
739 yOffset = pt[x, y].Y;
740 if (yOffset >= 0 && yOffset < nHeight && xOffset >= 0 && xOffset < nWidth)
741 {
742 p[0] = pSrc[(yOffset * scanline) + (xOffset * 3)];
743 p[1] = pSrc[(yOffset * scanline) + (xOffset * 3) + 1];
744 p[2] = pSrc[(yOffset * scanline) + (xOffset * 3) + 2];
745 }
746 p += 3;
747 }
748 p += nOffset;
749 }
750 }
751 src.UnlockBits(bitmapData);
752 bSrc.UnlockBits(bmSrc);
753 return src;
754 }
755 #endregion
756
757 #region 生成随机字符串
758 /// <summary>
759 /// 生成随机字符串
760 /// </summary>
761 /// <returns></returns>
762 public string GetRandomString(Int32 textLength)
763 {
764 string[] randomArray = charCollection.Split(','); //将字符串生成数组
765 int arrayLength = randomArray.Length;
766 string randomString = "";
767 for (int i = 0; i < textLength; i++)
768 {
769 randomString += randomArray[random.Next(0, arrayLength)];
770 }
771 return randomString; //长度是textLength +1
772 }
773 #endregion
774
775 #region 随机生成颜色值
776 /// <summary>
777 /// 生成随机深颜色
778 /// </summary>
779 /// <returns></returns>
780 public Color GetRandomDeepColor()
781 {
782 int nRed, nGreen, nBlue;
783 // nBlue,nRed nGreen 相差大一点 nGreen 小一些
784 //int high = 255;
785 int redLow = 160;
786 int greenLow = 100;
787 int blueLow = 160;
788 nRed = random.Next(redLow);
789 nGreen = random.Next(greenLow);
790 nBlue = random.Next(blueLow);
791 Color color = Color.FromArgb(nRed, nGreen, nBlue);
792 return color;
793 }
794 /// <summary>
795 /// 生成随机浅颜色
796 /// </summary>
797 /// <returns>randomColor</returns>
798 public Color GetRandomLightColor()
799 {
800 int nRed, nGreen, nBlue;
801 //越大颜色越浅
802 int low = 180; //色彩的下限
803 int high = 255; //色彩的上限
804 nRed = random.Next(high) % (high - low) + low;
805 nGreen = random.Next(high) % (high - low) + low;
806 nBlue = random.Next(high) % (high - low) + low;
807 Color color = Color.FromArgb(nRed, nGreen, nBlue);
808 return color;
809 }
810 /// <summary>
811 /// 获取与当前颜色值相加后的颜色
812 /// </summary>
813 /// <param name="c"></param>
814 /// <returns></returns>
815 public Color GetLightColor(Color c, Int32 value)
816 {
817 int nRed = c.R, nGreen = c.G, nBlue = c.B;
818 //越大颜色越浅
819 if (nRed + value < 255 && nRed + value > 0)
820 {
821 nRed = c.R + 40;
822 }
823 if (nGreen + value < 255 && nGreen + value > 0)
824 {
825 nGreen = c.G + 40;
826 }
827 if (nBlue + value < 255 && nBlue + value > 0)
828 {
829 nBlue = c.B + 40;
830 }
831 Color color = Color.FromArgb(nRed, nGreen, nBlue);
832 return color;
833 }
834 #endregion
835
836 #region 绘制圆角矩形
837 /// <summary>
838 /// C# GDI+ 绘制圆角矩形
839 /// </summary>
840 /// <param name="g">Graphics 对象</param>
841 /// <param name="rectangle">Rectangle 对象，圆角矩形区域</param>
842 /// <param name="borderColor">边框颜色</param>
843 /// <param name="borderWidth">边框宽度</param>
844 /// <param name="r">圆角半径</param>
845 private static void DrawRoundRectangle(Graphics g, Rectangle rectangle, Color borderColor, float borderWidth, int r)
846 {
847 // 如要使边缘平滑，请取消下行的注释
848 g.SmoothingMode = SmoothingMode.HighQuality;
849 Pen p = new Pen(borderColor, borderWidth);
850 // 调用 getRoundRectangle 得到圆角矩形的路径，然后再进行绘制
851 g.DrawPath(p, getRoundRectangle(rectangle, r));
852 }
853 #endregion
854
855 #region 根据普通矩形得到圆角矩形的路径
856 /// <summary>
857 /// 根据普通矩形得到圆角矩形的路径
858 /// </summary>
859 /// <param name="rectangle">原始矩形</param>
860 /// <param name="r">半径</param>
861 /// <returns>图形路径</returns>
862 private static GraphicsPath getRoundRectangle(Rectangle rectangle, int r)
863 {
864 int l = 2 * r;
865 // 把圆角矩形分成八段直线、弧的组合，依次加到路径中
866 GraphicsPath gp = new GraphicsPath();
867 gp.AddLine(new Point(rectangle.X + r, rectangle.Y), new Point(rectangle.Right - r, rectangle.Y));
868 gp.AddArc(new Rectangle(rectangle.Right - l, rectangle.Y, l, l), 270F, 90F);
869 gp.AddLine(new Point(rectangle.Right, rectangle.Y + r), new Point(rectangle.Right, rectangle.Bottom - r));
870 gp.AddArc(new Rectangle(rectangle.Right - l, rectangle.Bottom - l, l, l), 0F, 90F);
871 gp.AddLine(new Point(rectangle.Right - r, rectangle.Bottom), new Point(rectangle.X + r, rectangle.Bottom));
872 gp.AddArc(new Rectangle(rectangle.X, rectangle.Bottom - l, l, l), 90F, 90F);
873 gp.AddLine(new Point(rectangle.X, rectangle.Bottom - r), new Point(rectangle.X, rectangle.Y + r));
874 gp.AddArc(new Rectangle(rectangle.X, rectangle.Y, l, l), 180F, 90F);
875 return gp;
876 }
877 #endregion
878 }View Code
调用
1 private void frmValidateCode_Load(object sender, EventArgs e)
2 {
3 ValidateCode vCode = new ValidateCode();
4 string code = vCode.GetRandomString(5);
5 MemoryStream stream = vCode.CreateImage(code);
6 pictureBox1.Image = new Bitmap(stream);
7 }效果
转载于:https://www.cnblogs.com/WarBlog/p/11189717.html
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