android端实现验证码随机生成功能

本文实例为大家分享了android端生成随机验证码的具体代码，供大家参考，具体内容如下

package com.nobeg.util; 

import java.util.Random; 

import android.graphics.Bitmap;
import android.graphics.Canvas;
import android.graphics.Color;
import android.graphics.Paint;
import android.graphics.Bitmap.Config; 

public class Code { 

 private static final char[] CHARS = {
  '2', '3', '4', '5', '6', '7', '8', '9',
  'a', 'b', 'c', 'd', 'e', 'f', 'g', 'h', 'j', 'k', 'l', 'm',
  'n', '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', '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
 private static final int DEFAULT_CODE_LENGTH = 3;
 private static final int DEFAULT_FONT_SIZE = 25;
 private static final int DEFAULT_LINE_NUMBER = 2;
 private static final int BASE_PADDING_LEFT = 5, RANGE_PADDING_LEFT = 15, BASE_PADDING_TOP = 15, RANGE_PADDING_TOP = 20;
 private static final int DEFAULT_WIDTH = 60, DEFAULT_HEIGHT = 40; 

 //settings decided by the layout xml
 //canvas width and height
 private int width = DEFAULT_WIDTH, height = DEFAULT_HEIGHT; 

 //random word space and pading_top
 private 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 size
 private int codeLength = DEFAULT_CODE_LENGTH, line_number = DEFAULT_LINE_NUMBER, font_size = DEFAULT_FONT_SIZE; 

 //variables
 private 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, Config.ARGB_8888);
  Canvas c = new Canvas(bp); 

  code = createCode(); 

  c.drawColor(Color.WHITE);
  Paint paint = new Paint();
  paint.setTextSize(font_size); 

  for (int i = 0; i < code.length(); i++) {
   randomTextStyle(paint);
   randomPadding();
   c.drawText(code.charAt(i) + "", padding_left, padding_top, paint);
  } 

  for (int i = 0; i < line_number; i++) {
   drawLine(c, paint);
  } 

  c.save( Canvas.ALL_SAVE_FLAG );//保存
  c.restore();//
  return bp;
 } 

 public String getCode() {
  return code;
 } 

 //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();
 } 

 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);
 } 

 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);
 } 

 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
 } 

 private void randomPadding() {
  padding_left += base_padding_left + random.nextInt(range_padding_left);
  padding_top = base_padding_top + random.nextInt(range_padding_top);
 }
} 

java代码：

yanzhengma_img = (ImageView) findViewById(R.id.yanzhengma_img);
  yanzhengma_huan = (Button) findViewById(R.id.yanzhengma_huan);
  yanzhengma_val = (EditText) findViewById(R.id.yanzhengma_val); 

   yanzhengma_img.setImageBitmap(code.getInstance().createBitmap()); 

   System.out.println("验证码："+code.getInstance().getCode()); 

   yanzhengma_huan.setOnClickListener(new View.OnClickListener() { 

   public void onClick(View v) { 

   yanzhengma_img.setImageBitmap(code.getInstance().createBitmap());
   System.out.println("验证码："+code.getInstance().getCode());
   }
  });

以上就是本文的全部内容，希望对大家的学习有所帮助，也希望大家多多支持我们。