Android实现随机生成验证码 Android实现随机生成验证码

本文实例为大家分享了Android验证码的随机生成代码，供大家参考，具体内容如下
Code.java

package com.example.myapp; import android.graphics.Bitmap; import android.graphics.Canvas; import android.graphics.Color; import android.graphics.Paint; import java.util.Random; public class Code {/*** 随机数数组* 去除了易混淆的数字 0 和字母 o O*数字 1 和字母 i I l L*数字 6 和字母 b*数字 9 和字母 q*字母 c C 和 G*字母 t （经常和随机线混在一起看不清）*/private static final char[] CHARS = {'2', '3', '4', '5','7', '8','a','d', 'e', 'f', 'g', 'h', 'j', 'k', 'm','n', 'p','r', 's','u', 'v', 'w', 'x', 'y', 'z','A', 'B','D', 'E', 'F','H','J', 'K', 'M','N', 'P', 'Q', 'R', 'S', 'T', 'U', 'V', 'W', 'X', 'Y', 'Z'}; private static Code bmpCode; public static Code getInstance() {if(bmpCode == null)bmpCode = new Code(); return bmpCode; }//default settings//验证码默认随机数的个数private static final int DEFAULT_CODE_LENGTH = 4; //默认字体大小private static final int DEFAULT_FONT_SIZE = 25; //默认线条的条数private static final int DEFAULT_LINE_NUMBER = 5; //padding值private static final int BASE_PADDING_LEFT = 10, RANGE_PADDING_LEFT = 15, BASE_PADDING_TOP = 15, RANGE_PADDING_TOP = 20; //验证码的默认宽高private static final int DEFAULT_WIDTH = 100, DEFAULT_HEIGHT = 40; //settings decided by the layout xml//canvas width and heightprivate int width = DEFAULT_WIDTH, height = DEFAULT_HEIGHT; //random word space and pading_topprivate int base_padding_left = BASE_PADDING_LEFT, range_padding_left = RANGE_PADDING_LEFT,base_padding_top = BASE_PADDING_TOP, range_padding_top = RANGE_PADDING_TOP; //number of chars, lines; font sizeprivate int codeLength = DEFAULT_CODE_LENGTH, line_number = DEFAULT_LINE_NUMBER, font_size = DEFAULT_FONT_SIZE; //variablesprivate String code; private int padding_left, padding_top; private Random random = new Random(); //验证码图片public Bitmap createBitmap() {padding_left = 0; Bitmap bp = Bitmap.createBitmap(width, height, Bitmap.Config.ARGB_8888); Canvas c = new Canvas(bp); code = createCode(); c.drawColor(Color.WHITE); Paint paint = new Paint(); paint.setAntiAlias(true); paint.setTextSize(font_size); //画验证码for (int i = 0; i < code.length(); i++) {randomTextStyle(paint); randomPadding(); c.drawText(code.charAt(i) + "", padding_left, padding_top, paint); }//画线条for (int i = 0; i < line_number; i++) {drawLine(c, paint); }//c.save( Canvas.ALL_SAVE_FLAG ); //保存c.save(); //保存c.restore(); //return bp; }public String getCode() {return code; }//生成验证码private String createCode() {StringBuilder buffer = new StringBuilder(); for (int i = 0; i < codeLength; i++) {buffer.append(CHARS[random.nextInt(CHARS.length)]); }return buffer.toString(); }//画干扰线private void drawLine(Canvas canvas, Paint paint) {int color = randomColor(); int startX = random.nextInt(width); int startY = random.nextInt(height); int stopX = random.nextInt(width); int stopY = random.nextInt(height); paint.setStrokeWidth(1); paint.setColor(color); canvas.drawLine(startX, startY, stopX, stopY, paint); }//生成随机颜色private int randomColor() {return randomColor(1); }private int randomColor(int rate) {int red = random.nextInt(256) / rate; int green = random.nextInt(256) / rate; int blue = random.nextInt(256) / rate; return Color.rgb(red, green, blue); }//随机生成文字样式，颜色，粗细，倾斜度private void randomTextStyle(Paint paint) {int color = randomColor(); paint.setColor(color); paint.setFakeBoldText(random.nextBoolean()); //true为粗体，false为非粗体float skewX = random.nextInt(11) / 10; skewX = random.nextBoolean() ? skewX : -skewX; paint.setTextSkewX(skewX); //float类型参数，负数表示右斜，整数左斜//paint.setUnderlineText(true); //true为下划线，false为非下划线//paint.setStrikeThruText(true); //true为删除线，false为非删除线}//随机生成padding值private void randomPadding() {padding_left += base_padding_left + random.nextInt(range_padding_left); padding_top = base_padding_top + random.nextInt(range_padding_top); }}

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