Android随机生成验证码

public class code { 
 
 //随机数数组 
 private static final char[] chars = { 
   '2', '3', '4', '5', '6', '7', '8', '9', 
   'a', 'b', 'c', 'd', 'e', 'f', 'g', 'h', 'j', 'k', '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 
 //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 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.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.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); 
 } 
} 

<?xml version="1.0" encoding="utf-8"?> 
<linearlayout xmlns:android="http://schemas.android.com/apk/res/android" 
 android:layout_width="match_parent" 
 android:layout_height="match_parent" 
 android:orientation="vertical" > 
 
 <relativelayout 
  android:layout_width="match_parent" 
  android:layout_height="50dp" 
  android:background="@color/main_color_white" > 
  <textview 
   android:id="@+id/tv_title" 
   android:layout_width="wrap_content" 
   android:layout_height="wrap_content" 
   android:layout_centerinparent="true" 
   android:text="找回密码" 
   android:textcolor="@color/loan_butbackground" 
   android:textsize="20sp" /> 
 </relativelayout> 
 
 <linearlayout 
  android:layout_width="match_parent" 
  android:layout_height="40dp" 
  android:layout_margintop="30dp" 
  android:orientation="vertical" 
  android:layout_marginleft="15dp" 
  android:layout_marginright="15dp" 
  android:background="@drawable/security_code_bg"> 
 
   
 
  <linearlayout 
   android:layout_width="match_parent" 
   android:layout_height="match_parent" 
   android:gravity="center_vertical" 
   android:orientation="horizontal" > 
 
   <textview 
    android:layout_width="wrap_content" 
    android:layout_height="wrap_content" 
    android:layout_marginleft="20dp" 
    android:layout_marginright="20dp" 
    android:text="中国+86" 
    android:textcolor="#a2cd5a" 
    android:textsize="16sp" /> 
 
   <view 
    android:layout_width="0.1dp" 
    android:layout_height="match_parent" 
    android:background="@color/loan_butbackground" /> 
 
   <edittext 
    android:id="@+id/et_forgetpass_phonenum" 
    android:layout_width="match_parent" 
    android:layout_height="wrap_content" 
    android:layout_marginleft="20dp" 
    android:background="@null" 
    android:digits="0123456789" 
    android:hint="请填入您的手机号" 
    android:inputtype="number" 
    android:maxlength="11" 
    android:textsize="16sp" /> 
  </linearlayout> 
 </linearlayout> 
 
  
 
 <linearlayout 
   
  android:layout_width="match_parent" 
  android:layout_height="wrap_content" 
  android:layout_marginleft="15dp" 
  android:layout_marginright="15dp" 
  android:layout_margintop="20dp" 
  android:orientation="horizontal" > 
 
  <linearlayout 
   android:layout_width="wrap_content" 
   android:layout_height="40dp" 
   android:background="@drawable/security_code_bg" > 
 
   <edittext 
    android:id="@+id/et_phonecodes" 
    android:layout_width="match_parent" 
    android:layout_height="match_parent" 
    android:layout_marginleft="10dp" 
    android:layout_marginright="10dp" 
    android:background="@null" 
    android:hint="请输入右侧验证码" /> 
  </linearlayout> 
 
  <imageview 
   android:id="@+id/iv_showcode" 
   android:layout_width="100dp" 
   android:layout_marginleft="10dp" 
   android:layout_height="match_parent" /> 
   
 </linearlayout> 
 
 <button 
  android:id="@+id/but_forgetpass_tosetcodes" 
  android:layout_width="match_parent" 
  android:layout_height="wrap_content" 
  android:layout_margin="20dp" 
  android:background="@drawable/buttonshape" 
  android:text="提交验证码" 
  android:textcolor="@color/main_color_white" /> 
 
</linearlayout> 

public class mainactivity extends activity implements onclicklistener { 
 public static final string tag = mainactivity.class.getname(); 
 private imageview iv_showcode; 
 private edittext et_phonecode; 
 private edittext et_phonenum; 
 //产生的验证码 
 private string realcode; 
 
 @override 
 protected void oncreate(bundle savedinstancestate) { 
  super.oncreate(savedinstancestate); 
  setcontentview(r.layout.activity_main); 
 
  et_phonecode = (edittext) findviewbyid(r.id.et_phonecodes); 
  button but_tosetcode = (button) findviewbyid(r.id.but_forgetpass_tosetcodes); 
  but_tosetcode.setonclicklistener(this); 
  iv_showcode = (imageview) findviewbyid(r.id.iv_showcode); 
  //将验证码用图片的形式显示出来 
  iv_showcode.setimagebitmap(code.getinstance().createbitmap()); 
  realcode = code.getinstance().getcode().tolowercase(); 
  iv_showcode.setonclicklistener(this); 
 } 
 
 @override 
 public void onclick(view v) { 
  switch (v.getid()) { 
   case r.id.iv_showcode: 
    iv_showcode.setimagebitmap(code.getinstance().createbitmap()); 
    realcode = code.getinstance().getcode().tolowercase(); 
    log.v(tag,"realcode"+realcode); 
    break; 
   case r.id.but_forgetpass_tosetcodes: 
    string phonecode = et_phonecode.gettext().tostring().tolowercase(); 
    string msg = "生成的验证码："+realcode+"输入的验证码:"+phonecode; 
    toast.maketext(mainactivity.this,msg,toast.length_long).show(); 
 
    if (phonecode.equals(realcode)) { 
     toast.maketext(mainactivity.this, phonecode + "验证码正确", toast.length_short).show(); 
    } else { 
     toast.maketext(mainactivity.this, phonecode + "验证码错误", toast.length_short).show(); 
    } 
    break; 
  } 
 } 
}