（转）Android 之生成图形验证码

2018-06-18 00:30:53来源：未知阅读 ()

  1 import android.graphics.Bitmap;
  2 import android.graphics.Canvas;
  3 import android.graphics.Color;
  4 import android.graphics.Paint;
  5 import java.util.Random;
  6 
  7 /**
  8  * Created by ekikousei易皇星 on 16/11/21.
  9  * E-mail:13764664731@163.com
 10  * Signature:缘分是本书,翻的不经意会错过,读的太认真会流泪!!
 11  * <p/>
 12  * TODO:类描述:  用于图形验证码的工具类
 13  */
 14 public class CodeUtils {
 15 
 16 //    private static final char[] CHARS = {
 17 //            '0', '1', '2', '3', '4', '5', '6', '7', '8', '9',
 18 //            'a', 'b', 'c', 'd', 'e', 'f', 'g', 'h', 'i', 'j', 'k', 'l', 'm',
 19 //            'n', 'o', 'p', 'q', 'r', 's', 't', 'u', 'v', 'w', 'x', 'y', 'z',
 20 //            'A', 'B', 'C', 'D', 'E', 'F', 'G', 'H', 'I', 'J', 'K', 'L', 'M',
 21 //            'N', 'O', 'P', 'Q', 'R', 'S', 'T', 'U', 'V', 'W', 'X', 'Y', 'Z'
 22 //    };
 23 
 24     private static final char[] CHARS = {
 25 
 26             'a', 'b', 'c', 'd', 'e', 'f', 'g', 'h', 'i', 'j', 'k', 'l', 'm',
 27             'n', 'o', 'p', 'q', 'r', 's', 't', 'u', 'v', 'w', 'x', 'y', 'z',
 28 
 29     };
 30 
 31     private static CodeUtils mCodeUtils;
 32     private int mPaddingLeft, mPaddingTop;
 33     private StringBuilder mBuilder = new StringBuilder();
 34     private Random mRandom = new Random();
 35 
 36     //Default Settings
 37 //    private static final int DEFAULT_CODE_LENGTH = 6;//验证码的长度  这里是6位
 38     private static final int DEFAULT_CODE_LENGTH = 4;//验证码的长度  这里是4位
 39     private static final int DEFAULT_FONT_SIZE = 60;//字体大小
 40     private static final int DEFAULT_LINE_NUMBER = 3;//多少条干扰线
 41     private static final int BASE_PADDING_LEFT = 40; //左边距
 42     private static final int RANGE_PADDING_LEFT = 30;//左边距范围值
 43     private static final int BASE_PADDING_TOP = 70;//上边距
 44     private static final int RANGE_PADDING_TOP = 15;//上边距范围值
 45     private static final int DEFAULT_WIDTH = 300;//默认宽度.图片的总宽
 46     private static final int DEFAULT_HEIGHT = 100;//默认高度.图片的总高
 47     private static final int DEFAULT_COLOR = 0xDF;//默认背景颜色值
 48 
 49     private String code;
 50 
 51     public static CodeUtils getInstance() {
 52         if (mCodeUtils == null) {
 53             mCodeUtils = new CodeUtils();
 54         }
 55         return mCodeUtils;
 56     }
 57 
 58     //生成验证码图片  返回类型为bitmap 直接用imageview.setbitmap()即可
 59     public Bitmap createBitmap() {
 60         mPaddingLeft = 0; //每次生成验证码图片时初始化
 61         mPaddingTop = 0;
 62 
 63         Bitmap bitmap = Bitmap.createBitmap(DEFAULT_WIDTH, DEFAULT_HEIGHT, Bitmap.Config.ARGB_8888);
 64         Canvas canvas = new Canvas(bitmap);
 65 
 66         code = createCode();
 67 
 68         canvas.drawColor(Color.rgb(DEFAULT_COLOR, DEFAULT_COLOR, DEFAULT_COLOR));
 69         Paint paint = new Paint();
 70         paint.setTextSize(DEFAULT_FONT_SIZE);
 71 
 72         for (int i = 0; i < code.length(); i++) {
 73             randomTextStyle(paint);
 74             randomPadding();
 75             canvas.drawText(code.charAt(i) + "", mPaddingLeft, mPaddingTop, paint);
 76         }
 77 
 78         //干扰线
 79         for (int i = 0; i < DEFAULT_LINE_NUMBER; i++) {
 80             drawLine(canvas, paint);
 81         }
 82 
 83         canvas.save(Canvas.ALL_SAVE_FLAG);//保存
 84         canvas.restore();
 85         return bitmap;
 86     }
 87 
 88     /**
 89      * 得到图片中的验证码字符串
 90      *
 91      * @return
 92      */
 93     public String getCode() {
 94         return code;
 95     }
 96 
 97     //生成验证码
 98     public String createCode() {
 99         mBuilder.delete(0, mBuilder.length()); //使用之前首先清空内容
100 
101         for (int i = 0; i < DEFAULT_CODE_LENGTH; i++) {
102             mBuilder.append(CHARS[mRandom.nextInt(CHARS.length)]);
103         }
104 
105         return mBuilder.toString();
106     }
107 
108     //生成干扰线
109     private void drawLine(Canvas canvas, Paint paint) {
110         int color = randomColor();
111         int startX = mRandom.nextInt(DEFAULT_WIDTH);
112         int startY = mRandom.nextInt(DEFAULT_HEIGHT);
113         int stopX = mRandom.nextInt(DEFAULT_WIDTH);
114         int stopY = mRandom.nextInt(DEFAULT_HEIGHT);
115         paint.setStrokeWidth(1);
116         paint.setColor(color);
117         canvas.drawLine(startX, startY, stopX, stopY, paint);
118     }
119 
120     //随机颜色
121     private int randomColor() {
122         mBuilder.delete(0, mBuilder.length()); //使用之前首先清空内容
123 
124         String haxString;
125         for (int i = 0; i < 3; i++) {
126             haxString = Integer.toHexString(mRandom.nextInt(0xFF));
127             if (haxString.length() == 1) {
128                 haxString = "0" + haxString;
129             }
130 
131             mBuilder.append(haxString);
132         }
133 
134         return Color.parseColor("#" + mBuilder.toString());
135     }
136 
137     //随机文本样式
138     private void randomTextStyle(Paint paint) {
139         int color = randomColor();
140         paint.setColor(color);
141         paint.setFakeBoldText(mRandom.nextBoolean());  //true为粗体，false为非粗体
142         float skewX = mRandom.nextInt(11) / 10;
143         skewX = mRandom.nextBoolean() ? skewX : -skewX;
144         paint.setTextSkewX(skewX); //float类型参数，负数表示右斜，整数左斜
145 //        paint.setUnderlineText(true); //true为下划线，false为非下划线
146 //        paint.setStrikeThruText(true); //true为删除线，false为非删除线
147     }
148 
149     //随机间距
150     private void randomPadding() {
151         mPaddingLeft += BASE_PADDING_LEFT + mRandom.nextInt(RANGE_PADDING_LEFT);
152         mPaddingTop = BASE_PADDING_TOP + mRandom.nextInt(RANGE_PADDING_TOP);
153     }
154 }