Android随机生成验证码

Android随机生成验证码,Android利用随机数绘制不规则的验证码，加强用户登录或者注册的安全性。
具体思路如下：
在一块固定宽高的画布上，画上固定个数的随机数字和字母，再画上固定条数的干扰线
随机数和干扰线的颜色随机生成，随机数的样式随机生成。

界面效果如下：

1、生成随机数代码，Code.java:

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); 
 } 
} 

2、编写布局文件，activity_main.xml:

<?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> 

3、在主界面生成随机数，校验验证码MainActivity.java:

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; 
  } 
 } 
} 

至此，基本功能已实现，源码下载：http://xiazai.jb51.net/201611/yuanma/AndroidSecurityCode(jb51.net).rar

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呐喊教程。

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