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:
<"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查字典教程网。
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