Android菜鸟练习第十五课 随机生成验证码及验证码图片

第一部分 生成随机验证码及图片的工具类

public class CreateRandomCode {//    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'//    };//设计随机数的随机范围private static final char[] CHARS = {'0', '1', '2', '3', '4', '5', '6', '7', '8', '9'};private static CreateRandomCode bmpCode;public static CreateRandomCode getInstance() {if (bmpCode == null)bmpCode = new CreateRandomCode();return bmpCode;}//default settingsprivate static final int DEFAULT_CODE_LENGTH = 4;private static final int DEFAULT_FONT_SIZE = 25;private static final int DEFAULT_LINE_NUMBER = 2;private static final int BASE_PADDING_LEFT = 10, RANGE_PADDING_LEFT = 15, BASE_PADDING_TOP = 15, RANGE_PADDING_TOP = 20;private static final int DEFAULT_WIDTH = 100, DEFAULT_HEIGHT = 40;//settings decided by the layout xml//canvas width and heightprivate int width = DEFAULT_WIDTH, height = DEFAULT_HEIGHT;//random word space and pading_topprivate 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 sizeprivate int codeLength = DEFAULT_CODE_LENGTH, line_number = DEFAULT_LINE_NUMBER, font_size = DEFAULT_FONT_SIZE;//variablesprivate 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;}//不同样式的验证码图片public Bitmap createNeatBitmap() {padding_left = 0;Bitmap bp = Bitmap.createBitmap(width, height, Config.ARGB_8888);Canvas c = new Canvas(bp);code = createCode();c.drawColor(Color.LTGRAY);//浅灰色画布Paint paint = new Paint();paint.setTextSize(font_size);for (int i = 0; i < code.length(); i++) {paint.setColor(Color.BLACK);paint.setFakeBoldText(true);  //true为粗体，false为非粗体padding_left += base_padding_left + 8;padding_top = base_padding_top + 12;c.drawText(code.charAt(i) + "", padding_left, padding_top, 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);}}

第二部分 Activity部分

public class MainActivity extends AppCompatActivity {public ImageView mIvCode;@Overrideprotected void onCreate(Bundle savedInstanceState) {super.onCreate(savedInstanceState);setContentView(R.layout.activity_main);mIvCode = (ImageView) findViewById(R.id.iv_code);mIvCode.setImageBitmap(CreateRandomCode.getInstance().createNeatBitmap());Toast.makeText(MainActivity.this,CreateRandomCode.getInstance().getCode(),Toast.LENGTH_SHORT).show();mIvCode.setOnClickListener(new View.OnClickListener() {@Overridepublic void onClick(View v) {mIvCode.setImageBitmap(CreateRandomCode.getInstance().createNeatBitmap());Toast.makeText(MainActivity.this,CreateRandomCode.getInstance().getCode(),Toast.LENGTH_SHORT).show();}});}}

第三部分 布局部分

<?xml version="1.0" encoding="utf-8"?><RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"android:id="@+id/activity_main"android:layout_width="match_parent"android:layout_height="match_parent"><ImageViewandroid:id="@+id/iv_code"android:layout_width="100dp"android:layout_height="45dp"android:background="#f3f3f3" /></RelativeLayout>