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。