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我们。